Return to the home page...

Go Back   Moyer Marine Atomic 4 Community - Home of the Afourians > Discussion Topics > Troubleshooting

Reply
 
Thread Tools Display Modes
  #1   IP: 24.214.124.111
Old 02-03-2013, 11:50 AM
Decca Decca is offline
Member
 
Join Date: Feb 2013
Posts: 4
Thanks: 0
Thanked 0 Times in 0 Posts
Lightbulb No power in gear

Hi everybody,

This is my first post although I have been following this forum everyday for quite a while now! I decided to post as I couldn't figure out the next step regarding my issue just by reading the older posts.

I've got an 1983 Catalina 30 with original A-4 engine 30hp, and the same problem as I could find in a handful of other posts: a power loss in gear only. However, I can't figure out who is the culprit. Have a look at the information below and let me know what you think

Problem: power loss, mainly in forward gear. Getting only 25 to 30% of the power, after that, I push the throttle forward with absolutely no result (and sometimes it feels like the engine is suffocating if I insist too much with full throttle, but not always). Revving up perfectly and "explosively" in neutral, revving up more or less fine (probably 50% to 75% power) in reverse and then simply going out of gear if I go above (not starving, going to neutral by itself). I am mainly concerned with the forward issue, as in reverse I get more than enough power to maneuver.

Additional information: doesn't stall, doesn't die, but systematically requires the choke to start on the first start only (subsequent starts are ok) at the very beginning (for literally half a second, if I keep the choke on too long, then it dies)

Troubleshooting:
- Compression checked, satisfactory result (in the 90 range for the four of them).
- All spark plugs changed (older ones looked ok, but changed anyway). Newer one got some black residue on them pretty quickly, I don't know if this is an important information... I cleaned them and put them back, they still look - and are - new)
- carburetor cleaned and rebuilt. Interesting fact here: I have 2 carburetors, and I cleaned and rebuilt both of them, and I get different results with each of them. The problem remains, but with carb #1 the engine idles at 700 RPM and the max RPM is 1200 (!!!) and with carb #2 the engine idles at 1,200 RPM and the max RPM is 1,800. This got me totally puzzled. I tried to idle at 700 RPM with carb #2 but under 1,100 it simply dies. while with carb #1 it cannot get above 1,200 RPM no matter what I do with the idling screw. What does it mean? I thought about it and I formulated the hypothesis that considering that the "range" of operation of both carburetors is similar (about 550 RPM variation from idle to max power), they probably both are fine, but simply work differently, and something else is probably limitating the RPM range at a delta of 550. What do the experts think?
- fuel filter checked: brand new, no issue, no debris, fuel flowing.
- I checked the prop and shaft: clean, no obstruction.
- I poured MMO in the spark plugs holes, hoping to 'free' a 'valve' ( I have no idea what I'm talking about, I just copied what other people did having the same issue) and in the gas.

What I didn't check yet (among the things that were recommended to check in other posts dealing with this problem) : exhaust system, and fuel pump. Exhaust system, because I know nothing about it, and because it's hard to get there, hard to find replacement, and I hope I can avoid this step (and it was replaced 4 years ago, so I thought that it is a little doubtful to already experience internal collapse). Fuel pump because before buying an expensive new one, I'd like to get some direction.
The symptoms and troubleshooting lead me to a dead end, and I don't know where to look next or how to look (can I check the fuel pump without buying a new one? could it be the fuel pump starving the carb?)

so... any idea or recommendation? I can spend time on it, I can't spend money on it, and my mechanical knowledge is very limited (got the boat a couple of months ago, and before that nada. trying to catch up as quickly as I can...)

Thank you for your help!

D
Reply With Quote
  #2   IP: 24.224.152.244
Old 02-03-2013, 01:41 PM
Mo's Avatar
Mo Mo is offline
Afourian MVP
 
Join Date: Jun 2007
Location: Halifax NS,
Posts: 4,470
Thanks: 292
Thanked 411 Times in 272 Posts
Smile Just a few more things.

Welcome aboard Decca,
Seems you did a few checks in the right direction so I have a few questions.

- Does it start easy?
- Does it stall when put in forward...or reverse.
- Does it bog down when put in forward or reverse.
- Does it run normally without misses etc in neutral and under load?
- Have you double checked the routing of the wires from the distributer to the plugs?...with two of those backwards it will run but not well.
- Do you know what size prop is on the boat?

Common culprits are:
-valves...ensure compression is checked with a guage, not by thumb method.
-exhaust blockage...yet to be determined.
-prop oversized.

There are a few more things that can do this but they usually end up as combination of problems regarding adjustment.

Regarding "transmission shifting":
- Expect to have to hold in into reverse. If you let go it is supposed to move back to the neutral position. When you pull the handle for reverse you should hear a short wind-up as the reversing gear engages....after that you should feel the boat start to move as the prop moves water.

- As for forward. You should feel an indent as it moves into forward...much the same as a shifter on a manual transmission in a car. At this point the boat should start moving forward and you notice prop moving water. RPMs will depend on the prop size. If the forward gear was slipping your rpms would / should rise and the boat makes less than normal speed.
__________________
Mo

"Odyssey"
1976 C&C 30 MKI

The pessimist complains about the wind.
The optimist expects it to change.
The realist adjusts the sails.
...Sir William Arthur Ward.
Reply With Quote
  #3   IP: 24.152.131.153
Old 02-03-2013, 02:32 PM
ndutton's Avatar
ndutton ndutton is offline
Afourian MVP
 
Join Date: May 2009
Location: Torrance, CA
Posts: 9,619
Thanks: 198
Thanked 2,208 Times in 1,425 Posts
For starters I'd check a couple of things that seem to be infrequently maintained if at all. Doing so will eliminate them from the mix and get the maintenance up to snuff.
  1. Clean the backfire flame arrester. Soak it in a bowl of lacquer thinner or similar aggressive solvent, brush clean both sides and blow out with compressed air.
  2. Oil the distributor advance flyweights. They are located under the points plate inside the distributor, should have both springs intact and move freely.
  3. Try throttling up by hand underway with the throttle cable removed from the carburetor and see if there's a difference. You'll need a helmsman and puhlenty of clear sea room.
Now a couple of questions:
  • With the engine off and in neutral, does the shaft turn easily by hand?
  • At max RPM does feathering the choke make a difference? It'll make a difference but is it better or worse?
  • OK, everybody calm down, do you have a PCV system? If yes, I'd remove it at least until the troubleshooting is complete.
__________________
Neil
1977 Catalina 30
San Pedro, California
prior boats 1987 Westsail 32, 1970 Catalina 22
Had my hands in a few others

Last edited by ndutton; 02-03-2013 at 02:37 PM.
Reply With Quote
  #4   IP: 216.115.121.240
Old 02-03-2013, 03:59 PM
lat 64's Avatar
lat 64 lat 64 is offline
Afourian MVP
 
Join Date: Oct 2008
Location: Fairbanks, Alaska
Posts: 1,964
Thanks: 39
Thanked 240 Times in 157 Posts
I think it's the reversing gear. perhaps not releasing due to maladjustment or some bits inside are broken.
I'm just being a bit too fast out of the gate with this guess, but iv'e been drinking lots of coffee today.

The only thing we don't really know is the history of the problem. The onset of these things can give good clues. So without that I think the above checklist are the best to start with.

Good post by the way. lots of data to get started with.

Russ
__________________
Whiskeyjack a '68 Columbia 36 rebuilt A-4 with 2:1

"Since when is napping doing nothing?"
Reply With Quote
  #5   IP: 24.224.152.244
Old 02-03-2013, 04:05 PM
Mo's Avatar
Mo Mo is offline
Afourian MVP
 
Join Date: Jun 2007
Location: Halifax NS,
Posts: 4,470
Thanks: 292
Thanked 411 Times in 272 Posts
Smile

Very possible Russ ... I did mention briefly how it should feel on the boat. If his compression numbers are correct then I would be leaning toward fouled or wrong size prop and Neil's number 2 suggestion (excellent by the way Neil... I didn't think of it but we've had that happen on here before as well).
__________________
Mo

"Odyssey"
1976 C&C 30 MKI

The pessimist complains about the wind.
The optimist expects it to change.
The realist adjusts the sails.
...Sir William Arthur Ward.
Reply With Quote
  #6   IP: 99.124.190.130
Old 02-03-2013, 09:44 PM
Al Schober's Avatar
Al Schober Al Schober is offline
Afourian MVP
 
Join Date: Jul 2009
Location: Uncasville, CT
Posts: 2,002
Thanks: 16
Thanked 578 Times in 405 Posts
Decca,
Welcome to the forum. Hope we can help! :-)
Sounds a lot like a clogged exhaust. If you happen to have one of the Moyer exhaust flanges with the pressure port, use it & advise. Since you probably don't..
Disconnect the exhaust piping from the manifold - don't have to move it much - 1/2" is plenty - and see if it runs any better. If so, you've found your problem. If not, get back and I'll dream up something different - or suggest the same as Neil..
Reply With Quote
  #7   IP: 24.214.124.111
Old 02-04-2013, 12:51 AM
Decca Decca is offline
Member
 
Join Date: Feb 2013
Posts: 4
Thanks: 0
Thanked 0 Times in 0 Posts
Thank you all for your answers!

@Mo:
Does it start easy? YES, depends on what you call easy but with a little choke starts in less than 5 sec.
- Does it stall when put in forward...or reverse. NO
- Does it bog down when put in forward or reverse. What does bog down mean? *sorry, english isn't my first language. but I don't think so because whatever it means, it behaves well in reverse and forward except for the loss of power.
- Does it run normally without misses etc in neutral and under load? YES
- Have you double checked the routing of the wires from the distributer to the plugs?...with two of those backwards it will run but not well. NO, and I'll check it in the coming days, as this is something I can do easily. thanks!
- Do you know what size prop is on the boat? NO, I just know it is clean and it was working before with the same prop. I will check when I get the opportunity.

-valves...ensure compression is checked with a guage, not by thumb method.
-exhaust blockage...yet to be determined.
Done properly with guage, too lazy to pull out the result sheet but all where between 85 and 95 so pretty darn ok for what I've been told.
-prop oversized. to be checked, will let you know. But it is not fouled, I had someone dive under the boat and he said everything was looking fine and aligned (and it was the guy from the boatyard)


And thank you a lot for the reversing gear explanation, now a lot of things make sense!

@neil

Clean the backfire flame arrester. Soak it in a bowl of lacquer thinner or similar aggressive solvent, brush clean both sides and blow out with compressed air.
DONE already, together with the carbs.
Oil the distributor advance flyweights. They are located under the points plate inside the distributor, should have both springs intact and move freely. I'll try to find those, and let you know how it goes.
Try throttling up by hand underway with the throttle cable removed from the carburetor and see if there's a difference. You'll need a helmsman and puhlenty of clear sea room. Did it (singlehanded! and there is no difference.

Now a couple of questions:

With the engine off and in neutral, does the shaft turn easily by hand?
YES
At max RPM does feathering the choke make a difference? It'll make a difference but is it better or worse? it is worse. the engine doesn't stand the choke except for starting (for the first few seconds)
OK, everybody calm down, do you have a PCV system? If yes, I'd remove it at least until the troubleshooting is complete. No I don't

@lat 64 : god forbides you're right I really don't want to deal with the reversing gear. Is there any easy way to check? But i would be enclined to think that based on what Mo said, I don't have an issue with the reverse gear. If it is meant to go out of gear by itself if not held as he mentioned, then I have no issue. I'll have to try to power up holding it, but even without holding it, it stays in reverse until 2,500 RPM at least which is fine, and I'm enclined to think that if I were to hold it it would just stay in gear. So what Mo said makes a lot of sense to me.

Conclusion: I'll try the few recommendations (for the reverse: hold it manually and see if it stays in gear, for the power loss: check the prop size, check the flyweights, and if I have to... check the exhaust (but only if I have no choice! removing this thing scares me...!)

I'll let you know how it goes! Thank you all for your responsiveness and for welcoming me in the afourian community

Just for the record, it was wonderfully sunny today so I still took the boat out and had a blast, even with my power loss issue and with all the other little issues I have that's how it is and will always be anyway!
Reply With Quote
  #8   IP: 24.224.152.244
Old 02-04-2013, 01:36 AM
Mo's Avatar
Mo Mo is offline
Afourian MVP
 
Join Date: Jun 2007
Location: Halifax NS,
Posts: 4,470
Thanks: 292
Thanked 411 Times in 272 Posts
Smile

Decca,
You have ruled out allot of things. Do you have an MMI manual from Moyer Marine. Allot of these boats are sold with one aboard...you never know. If not you will be needing one...

The firing order is 1243. I will tell you the set up from looking in over the engine toward the rear of the boat....I'm taking for granted that your engine is flywheel forward. Typically, they are set up as below if the distributor hasn't been moved....before pulling anything off check the route of each first. If number 1 is in a different position other than the 9 oclock area let us know before you change anything. If the no 1 is where I'm telling you (below) check the routing ...very common for 3 and 4 to be mixed up.

"Usually" No. 1 wire is the one toward the 9 O'clock position on the distributer, as you look in over the engine from the front...that wire goes to number 1 plug, most forward on the engine toward you.

No 2 wire is in the 12 Oclock position as you look in from the front and it goes to 2nd plug from front of engine

No 4 wire is next...it's at 3 Oclock as you are looking in over the engine...it goes to the 3rd plug back from front of the engine.

No 3 wire is at 6 Oclock position, closest to you, and it goes to the 4th and rear plug.

So that should be the wiring. If that looks OK remove the distributor cap ... I usually just remove the coil wire and leave the plug wires on doing this little job. Remove rotor button. Now you should see a plate (silver metal color if not too rusty)....there are 2 flat head screws holding it ... these are out on the edge of the metal plate securing it to the distrib...if you have points and condenser don't take the screws out of them or your EI if that is there...leave them where they are and don't move them...it will all go back into place. Once those two screws are removed gently lift the plate...might be a cloth looking thing under there but don't remove it...some still have it ..some don't. The springs will be right in front of you...two small ones. Check to ensure not broken and spray liberally with lubricating oil. Put back together reverse order...double check your wires again if you take them off.

You should ask the PO what kind of performance he got in forward as well. You and Al have both mentioned exhaust and I know you don't want to go there...but that could be the problem. I was just going through the easy stuff first. Usually with the exhaust there are a few problem areas...one is enough to hurt your performance.
-sometimes a blockage in manifold....haven't seen it myself.
-collapsed exhaust hose.
-most common...rust flaking off and blocking the metal hot exhaust.

Accessibility is the major factor in how hard this is going to be to fix the hot exhaust ... if it turns out to be the problem. The actual parts and assembly are not that bad to do...I did mine in 3 hrs. I let go the exhaust hose at the rear of the hot exhaust, took off carb, take off 3 nuts on exhaust manifold, let go small hose from T-stat to manifold....then move the whole manifold and hot exhaust to the right a couple of inches so that it clear the studs you just took those 3 nuts off. The gasket may stay on block or manifold...it might be reusable so try to protect from impact. Move the whole thing toward you, manifold and hot exhaust as one piece...might have to wind it through and turn it etc to get it out....might work just fine for you if it comes to that. Might be best to take some measuments, pics or even build a new hot exhaust just like the one you have before you take it off the manifold...by this I mean take it out of the boat first then build you new one like what you have in front of you, then take the old one off and re-istall the new one.

Reversing Gear:...usually not a major at all. I have a feeling it might be OK if you can spin the shaft by hand when in neutral. It should not stick / hold in reverse though. If you let go pressure it should drop out of gear in 1-2 seconds.

Don't sweat it. But talk to that previous owner if you can and see what kind of rpms he had in forward. I've seen A4's so over-propped they couldn't get out of their own way. We check the things that don't cost money first.
__________________
Mo

"Odyssey"
1976 C&C 30 MKI

The pessimist complains about the wind.
The optimist expects it to change.
The realist adjusts the sails.
...Sir William Arthur Ward.

Last edited by Mo; 02-04-2013 at 12:22 PM.
Reply With Quote
  #9   IP: 216.115.121.240
Old 02-04-2013, 02:40 AM
lat 64's Avatar
lat 64 lat 64 is offline
Afourian MVP
 
Join Date: Oct 2008
Location: Fairbanks, Alaska
Posts: 1,964
Thanks: 39
Thanked 240 Times in 157 Posts
I am trying to make sense of the difference in performance from forward to reverse. Decca, You said it works much better in reverse, right?
And, the motor revs up "explosively" in neutral?

The over-proped idea(that is to say too big of a propellor) fit this simple explanation.

The reverse gear is a reduction of 1.27:1. This means the engine would always have better rpms in reverse than forward. Does this make sense to others or perhaps is this a non-issue for diagnosis?

I'm only pursuing this line of thinking because Mo, Niel, and Al have covered the engine nicely and I can not add better suggestions there. Keep my ideas in the box with the fishing bait, then throw them out when they get too old and they won't smell up the boat.


Nice to learn that SOMEONE gets to sail in the winter!

Russ
__________________
Whiskeyjack a '68 Columbia 36 rebuilt A-4 with 2:1

"Since when is napping doing nothing?"

Last edited by lat 64; 02-04-2013 at 02:44 AM.
Reply With Quote
  #10   IP: 76.7.144.132
Old 02-04-2013, 04:03 AM
Marian Claire's Avatar
Marian Claire Marian Claire is offline
Afourian MVP
 
Join Date: Aug 2007
Posts: 1,797
Thanks: 33
Thanked 129 Times in 94 Posts
Any history on how the engine ran in the past? Have you tried removing one of the plug wires while running under load? http://www.moyermarine.com/faq/1.1.html Welcome to the forum. Dan S/V Marian Claire
Reply With Quote
  #11   IP: 70.53.225.237
Old 02-04-2013, 08:58 AM
Sony2000 Sony2000 is offline
 
Join Date: Dec 2011
Location: Montreal, QC. Canada
Posts: 424
Thanks: 0
Thanked 0 Times in 0 Posts
My boat was possibly referred to by Mo, as being the one that was overproped. Max rpm was 1100 at the time and I believe the PO from 5 years earlier, operated the boat like that. So I went from the 12X9 I think, to the plastic one that is 11X7, while the boat is on the hard this winter. A rough estimate is that I can expect a 3"x200 rpm=600 rpm increase, this Spring.
Since you are afloat, do check that each cylinder is firing when under load.
Reply With Quote
  #12   IP: 96.229.18.9
Old 02-04-2013, 09:02 AM
Dave Neptune Dave Neptune is offline
Afourian MVP, Professor Emeritus
 
Join Date: Jan 2007
Location: Grove, Oklahoma
Posts: 5,035
Thanks: 711
Thanked 1,289 Times in 839 Posts
Lightbulb How & ?

Decca, sounds like a plugged exhaust or and/or a clutch adjustment to me.
Only one question here now ~~Did it run fine before or did it just start slipping into neutral? Sounds to methatthe engineis running fine as you tried 2 carbs so I would not worry about tune or fuel at this point!
A bit more of a chronology of how it ~the problem(s) came to be noticed.
What have you touched,adjusted or moved?
Yeh,I know more than one question~consider the source~.

Dave Neptune
Reply With Quote
  #13   IP: 24.152.131.153
Old 02-04-2013, 10:54 AM
ndutton's Avatar
ndutton ndutton is offline
Afourian MVP
 
Join Date: May 2009
Location: Torrance, CA
Posts: 9,619
Thanks: 198
Thanked 2,208 Times in 1,425 Posts
It sounds like all the usual culprits have been addressed. After you double check the firing order it's likely time for an exhaust backpressure test. This can be safely done with a pressure gauge in the exhaust flange (the necessary components are found here and here) or you can do a noisy and dangerously noxious running test with the exhaust disconnected from the manifold. Be careful with that one.

Maybe before that try a running test at the slip with the engine in forward gear and the shaft coupler disconnected.
__________________
Neil
1977 Catalina 30
San Pedro, California
prior boats 1987 Westsail 32, 1970 Catalina 22
Had my hands in a few others

Last edited by ndutton; 02-04-2013 at 11:03 AM. Reason: added links
Reply With Quote
  #14   IP: 68.4.106.201
Old 02-04-2013, 12:13 PM
yeahjohn yeahjohn is offline
Senior Member
 
Join Date: Jun 2012
Posts: 261
Thanks: 0
Thanked 6 Times in 5 Posts
Maybe you have done this but as Neil stated check your stuffing box. Our packing glan appeared to be in good order and turned by hand with engine off but once put into gear would automatically freeze up because the stuffing was more like charcoal. So maybe just unscrew the packing glan and check it out for yourself. We had two mechanics tell us we need a new engine... So triple check the extremely basic. Did you just get the boat or did your engine just develop these symptoms? I had very similar symptoms to you.
Reply With Quote
  #15   IP: 199.168.148.136
Old 02-04-2013, 01:16 PM
JOHN COOKSON JOHN COOKSON is offline
Afourian MVP, Professor Emeritus
 
Join Date: Nov 2008
Posts: 3,500
Thanks: 54
Thanked 855 Times in 629 Posts
Here's another quick and easy thing to check.
Disconnect the shift linkage at the shift lever on the engine and shift by hand.
Maybe just maybe all that has happened is your shift linkage somehow got out of adjustment and you are no longer shifting into full forward.

TRUE GRIT
Reply With Quote
  #16   IP: 24.224.152.244
Old 02-04-2013, 01:44 PM
Mo's Avatar
Mo Mo is offline
Afourian MVP
 
Join Date: Jun 2007
Location: Halifax NS,
Posts: 4,470
Thanks: 292
Thanked 411 Times in 272 Posts
Thumbs up

Excellent point John. Certainly worth a look while he's there at those checks.
__________________
Mo

"Odyssey"
1976 C&C 30 MKI

The pessimist complains about the wind.
The optimist expects it to change.
The realist adjusts the sails.
...Sir William Arthur Ward.
Reply With Quote
  #17   IP: 24.12.166.208
Old 02-20-2013, 04:35 PM
Decca Decca is offline
Member
 
Join Date: Feb 2013
Posts: 4
Thanks: 0
Thanked 0 Times in 0 Posts
Thumbs up back in business :)

Hey!
First of all, I have to say that I am totally stunned. I didn't expect so many advices and tips so quickly. Very impressive, and I am indeed very thankful.
It took me some time to get back to you guys, but I did some work !

So to go straight to the point: I got some improvement, but it is still not perfect. AND, I don't know HOW I improved it.... well. What I mainly did is that I played again with the carbs, and basically built a 3rd carb out of the 2 I had taking from each of them the parts that looked best, and putting them together with new gaskets, and did what Ndutton suggested (clean the flame arrestor again, oil the flyweights) and I also checked the prop myself (free and clean). Also checked and cleaned fuel lines and filter, all clean and flowing well, and I cleaned the fuel filter again anyway.
After all that, I went out sailing (as Lat 64 mentioned it, some of us ARE SAILING IN WINTER! but it is easy to do so when it is 70+ degrees outside and sunny ) and it... worked! I could reach 6.3 knots under power (it was only 4 knots before) and reach up to 2100 rpm, while idling at 800. Good idle, good power, good acceleration, and this was in quite heavy seas. Not really GOOD, but better. I think I have 75% of the power now. How I did it I have no idea, maybe the carb after all... maybe a combination...?

Anyway, 75% just isn't good enough, I want it all! So I'll keep working on it. It is actually not so much to get the extra power (now with 75% I feel safe enough) than to keep my engine healthy. He can do it, but he is clearly telling me that he is still not totally healthy and I want to take care of him

So let's keep going:
Here are a few answers to the questions I received.

- the plugs are set up correctly. I know this because the PO was the first and only owner, and he was very very meticulous. Everything he did, purchased, or noticed related to this boat since 1983 is documented and kept. I have a diagram of how the plugs should be wired.

- the history of the engine is as follows: worked fine until last summer. Was left without being used for a couple of months by PO when I purchased it. Power issue was there since day 1 (well, I didn't pay much attention to it on the very first day, but at least from day 2). The owner had similar issues that were always solved with change of plugs and MMO, which I did. Twice.

- the prop is clean. I don't know about it's size, but it is the same prop the PO used without any issue previously. I dived under the boat and it's all clean, all good.

Out of the suggestions that came, I really liked the 2 following (because they are easy to check ) and will check them.
- the stuffing box (John could you tell me where to find it? You say " unscrew the packing glan"? I really know nothing about engines, and if you could be a little bit more detailed about where to locate this thing...)

- the shift linkage. Never thought of this. Thanks, John (the other John). Will give it a check. I'm praying for it to be the issue, that would be so so great.

However, I have the terrible feeling that Mo and Ndutton are 100% right and that I'll soon have no other choice than considering the exhaust. I also have to admit that however the PO was very careful, after 30 years the engine is kind of heavily rusted and small rusted parts are falling everywhere. Therefore I wouldn't be surprised if rust were to be found in the exhaust, as I found rusted parts pretty much everywhere else (on the ground, in the flame arrestor, around the plugs, ...)

Again, thank you all for your help, I feel like I just had a team of skilled mechanics come to my boat, and it feels great!

I WILL TAKE SOME TIME TO COME BACK TO YOU, because I'm not on the boat anymore (holidays, visiting family!) and won't be for the next 3 weeks at least. And then, I'll be do a passage ( a slow, coastal cruising, farniente passage) from Panama city to Tampa, FL (70 degrees just isn't enough. I want warmer! just kidding). Once I'll be in Tampa, I'll get back to work, and let you know how it goes.

Cheers
D.
Reply With Quote
  #18   IP: 65.92.161.249
Old 02-20-2013, 05:41 PM
Sony2000 Sony2000 is offline
 
Join Date: Dec 2011
Location: Montreal, QC. Canada
Posts: 424
Thanks: 0
Thanked 0 Times in 0 Posts
Before going too far, what are the mixture settings on your carburators? Like 1 1/2 turns out from being "in".
Reply With Quote
  #19   IP: 24.152.131.153
Old 02-20-2013, 05:45 PM
ndutton's Avatar
ndutton ndutton is offline
Afourian MVP
 
Join Date: May 2009
Location: Torrance, CA
Posts: 9,619
Thanks: 198
Thanked 2,208 Times in 1,425 Posts
2100 RPM and 6.3 knots? Dude, that's all I've ever wrung out of mine. Assuming your prop is the typical diameter and pitch I think you're already there. I'd run it for a while and read the plugs, maybe make minute adjustments as the plugs indicate.

For reference the theoretical hull speed is 6.7 knots and that's in a dead flat calm; the factory Catalina 30 prop is 12x7x1 RH two blade.
__________________
Neil
1977 Catalina 30
San Pedro, California
prior boats 1987 Westsail 32, 1970 Catalina 22
Had my hands in a few others

Last edited by ndutton; 02-20-2013 at 10:19 PM.
Reply With Quote
  #20   IP: 98.189.172.157
Old 02-20-2013, 05:54 PM
yeahjohn yeahjohn is offline
Senior Member
 
Join Date: Jun 2012
Posts: 261
Thanks: 0
Thanked 6 Times in 5 Posts
I dream about those numbers... I max out at 1600 rpm and 5.5 knts with my martec folding prop. The stuffing box is where the shaft goes through the boat and into the water, it is the covered area right below the companion way ladder. The shaft is there, along with the shaft log (piece of tubing), and packing gland (the nut thing, with a lock nut). I would not mess with it until you can ask a dock neighbor who knows how to help you. This stuff is rather important because if it fails your boat will sink. Google proper maintenance etc.
Reply With Quote
  #21   IP: 199.168.148.136
Old 02-20-2013, 06:17 PM
JOHN COOKSON JOHN COOKSON is offline
Afourian MVP, Professor Emeritus
 
Join Date: Nov 2008
Posts: 3,500
Thanks: 54
Thanked 855 Times in 629 Posts
Decca
I reread this thread. I'm going to join in with the others that say after you have tried all of the other fixes and you are still not getting all the power you should it is time to look at the exhaust system.
Rubber exhaust tubing can collapse internally and still appear normal on the outside. There are many Catalina 30 owners in the forum that will be willing to help with the project. You are not alone when you are in the forum.

TRUE GRIT
Reply With Quote
  #22   IP: 24.224.152.244
Old 02-20-2013, 06:39 PM
Mo's Avatar
Mo Mo is offline
Afourian MVP
 
Join Date: Jun 2007
Location: Halifax NS,
Posts: 4,470
Thanks: 292
Thanked 411 Times in 272 Posts
Smile I think you have it.

If the engine is pushing the boat at 2100 / 6.3 kts in calm water I think you are there. It won't go faster. Neil has the same boat as you. Mine is a C&C 30 and I'd be lucky to push it at 6.2 with clean bottom and dead calm...that's all there is.
__________________
Mo

"Odyssey"
1976 C&C 30 MKI

The pessimist complains about the wind.
The optimist expects it to change.
The realist adjusts the sails.
...Sir William Arthur Ward.
Reply With Quote
  #23   IP: 108.28.109.76
Old 02-21-2013, 09:22 AM
edwardc's Avatar
edwardc edwardc is offline
Afourian MVP
 
Join Date: Aug 2009
Location: Laurel, MD
Posts: 2,509
Thanks: 153
Thanked 595 Times in 388 Posts
Decca,

With a 25' waterline, the theoretical hull speed is of the C30 is only 6.7 kts (1.34 x sqrt(LWL) ), so you're essentially there, as it takes increasingly large amounts of power as you approach hull speed.

But I had another question. How exactly are you judging or measuring "power"? You can't do it by the percent of the max throttle position, as our A4s have a carb that is capable of supplying a much larger displacement engine than we have (I'm sure Dave Neptune can give much better details). Once the engine is taking all it's capable of, there is no effect from applying further throttle. Even in a perfect A4, there will always be some "unused" throttle beyond the max RPM setting. This is normal, and not indicative of an under-performing engine.
__________________
@(^.^)@ Ed
1977 Pearson P-323 "Dolce Vita"
with rebuilt Atomic-4

Reply With Quote
  #24   IP: 24.12.166.208
Old 02-21-2013, 02:29 PM
Decca Decca is offline
Member
 
Join Date: Feb 2013
Posts: 4
Thanks: 0
Thanked 0 Times in 0 Posts
well, good to hear that I get some good figures, however here is my concern: I am aware of the hull speed limit and I do not expect to go faster. I expect to have extra throttle power. Right now, I can carefully reach the 6 knots after playing with the throttle, but still, it is not responding "very well" (sometimes I move the throttle up and there is no answer, then it decreases a little bit, then it increases again), and also I do not have this "extra power" that could be necessary if I had a strong current against me or other challenging conditions. The max I get in RPM barely gets me to this speed of 6knots, and then it is impossible to increase the power.

I did my homework and read that to bring a catalina 30 to hull speed an engine has to develop 10HP. So with 30 HP I should have plenty of extra power (not extra speed, I know) that I don't have.

Does it make sense? Do you still think that I have unrealistic expectations and that I cannot really get better than what I have right now?
Reply With Quote
  #25   IP: 141.0.9.76
Old 02-21-2013, 02:49 PM
Bold Rascal's Avatar
Bold Rascal Bold Rascal is offline
Senior Member
 
Join Date: Mar 2011
Location: Princess Anne, MD
Posts: 302
Thanks: 0
Thanked 1 Time in 1 Post
30Bhp

Hi Decca, Here's a cut N paste from an A4 manual PDF I found online a while back. I hope it post's correctly for you but according to the information available, 30BHP is not achieved until 3500 RPM.

Brake Horsepower
RPM 600 1000 1500 2000 2500 3000 3500
UJS-UJSR 4 7.1 11 15 18 — ---
UJ-UJR-UJVD 5 7.3 11.9 16.2 20 25 30

I'd be really happy to get 6 knots even in calm conditions. Maybe this year.
__________________
Mike, Slower-Lower Eastern shore, MD
1973 Pearson 33
1967 Bristol 27
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
No power in forward gear bmoore1974 Troubleshooting 8 05-29-2012 02:57 PM
No power when in gear Seabee Chief Troubleshooting 34 06-28-2010 01:24 PM
No power when in gear!!!!!!!!! penneypincher Troubleshooting 2 06-06-2008 09:58 PM
No power in gear Baltimore Sailor Troubleshooting 10 09-16-2007 09:27 PM


All times are GMT -4. The time now is 07:10 AM.


Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2024, vBulletin Solutions, Inc.


Universal® is a registered trademark of Westerbeke Corporation

Copyright © 2004-2024 Moyer Marine Inc.

All Rights Reserved