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  #51   IP: 99.240.133.157
Old 07-28-2018, 12:53 PM
Sange Sange is offline
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Engine throttle hesitates

Hi Everyone - thanks again for your feedback. Let me answer a few of your questions:

1. Timing and advance - I cannot comment on the exact procedure but I double checked that my mechanic optimized this during the initial tune up in the spring and again after installing the electronic conversion kit a few weeks ago and the engine ran solid during our one week trip and we motored for 12 hours.
2. Mechanical vs Electric Fuel Pump- I doubt the electrical pump is going to make a difference as I just had the mechanical pump re-built. Reading a few comments on this forum including Don's feedback from years ago it appears that A4 owners are evenly divided and it's a matter of opinion and preference. From what I've gathered the mechanical pump is designed to pull the fuel and the electric pushes the fuel. If the electric pump doesn't make a difference I'm simply reverting back to the re-built mechanical pump. My preference is to stick with the mechanical but we'll see what happens during Monday's test.
3. Air/fuel mixture has been optimized with both the old carb and the rebuilt carb installed a few days ago. This definitely makes a difference but does not get rid of the hesitation. It is set to run a bit richer
4. Hesitation - only occurs in gear when moving primarily from low throttle to high throttle. Does not occur at the dock when running off the dock lines which is strange to me.
5. Lead additive to fuel - Far stretch and was not suggested that it would fix the problem, just suggested for regular maintenance -I will not be doing this. However, up until now I've been using Startron for the fuel. I will start using MMO effective immediately and sourced some locally here in Ontario yesterday
6. A friend of mine with the same boat C&C30-A4, also had the hesitation issue. He found an issue with the compression and 2 valves sticking. He removed the plugs and applied the MMO to release the valves. He has been treating his fuel and oil with MMO for regular maintenance and it's working for his A4. I also checked the forum and a bunch of videos and everybody seems to swear by the MMO. Sooo, I will be doing the same moving forward effective immediately. I'm also going to buy a compression tester to record the values before and after applying the MMO to quantify the condition and improvement.
7. Fuel Filters - I only have one New primary fuel filter that was installed a few days ago at the same time the rebuilt carb was installed and new fuel lines were installed. I am now going to purchase and install an in-line polishing filter and fuel pressure gauge before the carb as suggested thank you. I will try this first before adding a 3rd and need to investigate this further. Do you have a picture of your set-up with the 3 filters that I can use as a reference?
8. Brand new plugs and wires installed during electronic ignition conversion. Yes they are in the correct firing order
9. Will examine plugs and take pics when I remove them to apply MMO to the valves
10. Re-built carb - The carb was sent out to a specialty carb re-build shop and thats all that they do. I was told that they use a kit and new gaskets so trust this was done correctly. The re-built carb definitely performs much better than the other carb and my choke is now working.
11. Fuel looks clean but I have no idea if there is crud in the fuel tank. How else can I determine this simply?
12. Exhaust system issue - can you please elaborate on the issue I should be looking into?

Thanks again guys. Your feedback and questions have been very helpful and much appreciated!!
Frank
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Old 07-28-2018, 04:58 PM
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Quote:
Originally Posted by Sange View Post
11. Fuel looks clean but I have no idea if there is crud in the fuel tank. How else can I determine this simply?
1) Disconnect the hose from the carb and crank the engine to collect some fuel in a glass jar (do not use a PLASTIC container - some of them dissolve in gas - I have determined this experimentally...) Examine the sample for clarity and bit and pieces.

2) Remove your fuel filter and empty it out into a glass container. Examine for crud.

3) Another less direct test is to disconnect the fuel line from the boat tank and connect it to an auxiliary tank. If the engine runs fine, strong indication of crud in the fuel in the boat tank. This is a little tricky to do away from the dock.

Hope that helps.

Peter

PS - MMO is available from COSTCO in Canada - they deliver it at no cost in a six pack for about $60

Last edited by Peter; 07-28-2018 at 05:01 PM.
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Sange (07-29-2018)
  #53   IP: 72.194.219.196
Old 07-28-2018, 06:21 PM
JOHN COOKSON JOHN COOKSON is offline
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[QUOTE=Peter;113616]1)
3) Another less direct test is to disconnect the fuel line from the boat tank and connect it to an auxiliary tank. If the engine runs fine, strong indication of crud in the fuel in the boat tank. This is a little tricky to do away from the dock.
Hope that helps.
Peter

If there's curd in the carb from dirty fuel from the boats tank supplying clean fuel might not help the engine run better.
The fuel pumps job is to supply gas the carburetor at the correct pressure. The carb takes over from there.
Let's quite guessing.
STEP1: Get clean fuel to the carb from an auxiliary tank at the correct pressure. Post the results. We'll go from there.

Sorry to be so direct.

TRUE GRIT
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  #54   IP: 99.240.133.157
Old 07-29-2018, 09:01 AM
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Engine Throttle hesitates

During my initial post I indicated that fresh fuel was used utilizing an auxiliary tank and then the ship's tank. This was done again after installing the new fuel line and re-built carb. NO CHANGE in performance. I forgot to list it in my summary below so I've added it for reference. Next update will be after I've completed item #6&7, compression test and adding a polishing fuel filter and fuel pressure gauge before the carb. Thanks again!

1. Timing and advance - I cannot comment on the exact procedure but I double checked that my mechanic optimized this during the initial tune up in the spring and again after installing the electronic conversion kit a few weeks ago and the engine ran solid during our one week trip and we motored for 12 hours.
2. Mechanical vs Electric Fuel Pump- I doubt the electrical pump is going to make a difference as I just had the mechanical pump re-built. Reading a few comments on this forum including Don's feedback from years ago it appears that A4 owners are evenly divided and it's a matter of opinion and preference. From what I've gathered the mechanical pump is designed to pull the fuel and the electric pushes the fuel. If the electric pump doesn't make a difference I'm simply reverting back to the re-built mechanical pump. My preference is to stick with the mechanical but we'll see what happens during Monday's test.
3. Air/fuel mixture has been optimized with both the old carb and the rebuilt carb installed a few days ago. This definitely makes a difference but does not get rid of the hesitation. It is set to run a bit richer
4. Hesitation - only occurs in gear when moving primarily from low throttle to high throttle. Does not occur at the dock when running off the dock lines which is strange to me.
5. Lead additive to fuel - Far stretch and was not suggested that it would fix the problem, just suggested for regular maintenance -I will not be doing this. However, up until now I've been using Startron for the fuel. I will start using MMO effective immediately and sourced some locally here in Ontario yesterday
6. A friend of mine with the same boat C&C30-A4, also had the hesitation issue. He found an issue with the compression and 2 valves sticking. He removed the plugs and applied the MMO to release the valves. He has been treating his fuel and oil with MMO for regular maintenance and it's working for his A4. I also checked the forum and a bunch of videos and everybody seems to swear by the MMO. Sooo, I will be doing the same moving forward effective immediately. I'm also going to buy a compression tester to record the values before and after applying the MMO to quantify the condition and improvement.
7. Fuel Filters - I only have one New primary fuel filter that was installed a few days ago at the same time the rebuilt carb was installed and new fuel lines were installed. I am now going to purchase and install an in-line polishing filter and fuel pressure gauge before the carb as suggested thank you. I will try this first before adding a 3rd and need to investigate this further. Do you have a picture of your set-up with the 3 filters that I can use as a reference?
8. Brand new plugs and wires installed during electronic ignition conversion. Yes they are in the correct firing order
9. Will examine plugs and take pics when I remove them to apply MMO to the valves
10. Re-built carb - The carb was sent out to a specialty carb re-build shop and thats all that they do. I was told that they use a kit and new gaskets so trust this was done correctly. The re-built carb definitely performs much better than the other carb and my choke is now working.
11. Fuel looks clean but I have no idea if there is crud in the fuel tank. How else can I determine this simply?
12. Exhaust system issue - can you please elaborate on the issue I should be looking into?
13. Fresh fuel has been used utilizing an auxiliary tank throughout each step of this process (old carb, re-built carb) and hasn't solved the issue. No difference has been observed between the auxiliary tank and the ship's tank.
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Old 07-29-2018, 11:59 AM
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I wonder if the specialty carb rebuild shop uses the same kit that Moyer sells, or one with the same jets, or if they are doing something different than Moyer recommends, which might create your symptom. Probably their work is not the problem. If they know what they are doing, they know the Moyer manual. You say it runs ok at idle, hesitates on acceleration, then runs rough, is that right? If it hesitates and then runs ok at higher rpm under load, you might as well go sailing. We always hear that the engine should accelerate 'almost explosively', in Don Moyer's phrase. If that happens, then your air/fuel mixture is optimized. There are two idle ports in the upper throat of the carb, one above the throttle valve and one below. When the valve opens, fuel flows out both of them. They are small and easy to miss. Unlike the jets, you can't remove them to see if they are obstructed, you can only run a wire in them. Myself, I like to rebuild and clean my own carburetor. That way I don't wonder what someone else did or didn't do to it, professional though they may be. If the carb and fuel are clean, the jets and ports are unobstructed, the float valve is good, there is no air leak at the gaskets, and the choke works properly, your carb is good. You definitely need an inline filter, make sure it points the right way. It's probably overkill for me to have two of them, on either side of the pump, but it makes me feel better. Make sure you replace inline filters when you clean the carb. Sometimes you can tell if an inline filter is clogged by blowing through it. Let us know what the fuel pressure gauge reads, and if it drops on acceleration. It shouldn't.
MMO is your friend. The old Universal engineers whose job was to run and test these engines while they were being made also swore by it.
With your mechanical fuel pump you can use the bail underneath it to pump fuel into a glass jar to inspect for water and crud. Your primary fuel filter should have a bowl at the bottom which you can drain and inspect the fuel there, too.
I have read here about old exhaust hoses delaminating internally and collapsing inside, restricting exhaust flow but not leaking. Hasn't happened to me yet.
I have no explanation for why it only runs badly away from the dock, unless your tank is so full of crud that tossing the boat around while motoring clogs the filters, and then the jets. This is common. But then it should still run badly at the dock, until the carb is cleaned and the filters replaced. Don't let your fuel level get too low, or this is more likely to happen. I hope you are using non-ethanol gas, so water in the fuel stays at the bottom of the tank, and doesn't disperse in the fuel, bringing the crud with it, IMO. You are on the verge of motoring success here, keep at it!
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Old 07-29-2018, 02:28 PM
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Originally Posted by Sange View Post
12. Exhaust system issue - can you please elaborate on the issue I should be looking into?
If your exhaust is old, there are various ways it can become blocked or partially blocked which causes a "back-pressure" that chokes the engine and would cause hesitation under load.

Read this thread for a bit more info...
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Old 07-31-2018, 02:00 PM
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Red face Engine Throttle Hesitation

So I had some good luck yesterday after a two week battle! The root cause of the issue appears to be the incorrect hose (compressor hose) was used for a portion of my fuel line from the previous owner, deteriorated over time and clogged the carb. Did the compression test yesterday and all cylinders were reading 100psi dry and 105psi wet with only slight 2psi variation. Through all the trial and error and issues with the choke it appears that my new plugs (3 weeks old) became fouled. I changed the plugs with an equivalent NGK BR6S that was in stock locally and the problem has been solved for the time being!! Engine is operating solid and runs smooth again and we then enjoyed a great night sailing. Will be heading out again tonight and hopefully were all set for our regatta this week. Just ordered the recommended Moyer plugs Champion RJ-12C so I have a spare on board. Will set gap at .035" per spec.
Lots of smart guys with great knowledge and experience on this forum and I would like to thank each of you for your help. Until the next time....
Thanks again - Frank
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  #58   IP: 71.222.3.150
Old 07-31-2018, 09:58 PM
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Originally Posted by Sange View Post
...my new plugs (3 weeks old) became fouled.
Frank-
Not to rain on your happyness...
But one should ask... why are my new plugs fouling?
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Last edited by roadnsky; 08-01-2018 at 10:32 AM.
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Old 07-31-2018, 10:53 PM
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Dissolved hose goo????
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Old 04-28-2019, 07:20 PM
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Ye olde "only runs with the choke out" thread.

After a winter spent rectifying the effects of the boat partner not shutting off the raw water intake when cranking the motor with no start, I finally took the boat out for a sea trial today.

Work done since last Fall:

-rebuild carb
-rebuild raw water pump
-rebuild heat exchanger
-new coil
-new points, cap, and rotor

The motor has been running fine at the dock, in neutral and in gear. In fact, it sounds better than ever. Today I took it out for a motor in fairly rough seas. Just off the dock it was purring along fine and then quit with a "starved for fuel" type shutdown and restarted immediatley. Ten minutes out into the bay it quit again and then started back up readily. Fifteen minutes later, it quit again and started reluctantly then gradually required full choke to run and we returned to the dock with no further shutdown.

Things that I will do before heading out for the coming weekend:

-Turn in the idle air screw to enrichen the mixture a bit.
-Change main and secondary fuel filters.
-Order a new fuel pump.

Any other suggestions?
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Old 04-28-2019, 08:12 PM
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Cityhix, from your story I would guess that you stirred up some "krap" in the fuel tank and it is now clogging the filter or filters. If you have a "polishing filter" just ahead of the carb the carb may just be OK. Sounds like you are starving for fuel. All to often I have seen a rough sea-state stir up a mess. Unfortunately cleaning the tank is not often easy.

What is the layout of your fuel system from the tank?

This would be an EXCELLENT time to install a fuel pressure gage which would easily diagnose a fuel "delivery" problem.

Dave Neptune
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Old 04-28-2019, 08:58 PM
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Quote:
Originally Posted by Dave Neptune View Post
Cityhix, from your story I would guess that you stirred up some "krap" in the fuel tank and it is now clogging the filter or filters. If you have a "polishing filter" just ahead of the carb the carb may just be OK. Sounds like you are starving for fuel. All to often I have seen a rough sea-state stir up a mess. Unfortunately cleaning the tank is not often easy.

What is the layout of your fuel system from the tank?

This would be an EXCELLENT time to install a fuel pressure gage which would easily diagnose a fuel "delivery" problem.

Dave Neptune
I have a fuel/water seperator/filter after the tank, a small polishing filter and then the Facet electric pump.

Would the fuel pressure gauge go between the pump and the carb? Can you recommend a gauge?
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Old 04-28-2019, 09:13 PM
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Cityhix, any cheap fuel pressure gage will work fine. The order of the system should be ~~ fuel filer separator ~ fuel pump ~ polishing filter ~ gage ~ carb.

The gage will let you know what the carb "sees" and that is what feeds it!! Once installed and any trouble rears it's head a quick look at the gage showing pressure means look elsewhere or perhaps inside the carb as the "delivery" of the fuel is OK.

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Old 04-29-2019, 08:42 AM
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Cityhix, Since you are already in it this deep, I would add "Clean the carb (again)" to your list as you may have gotten some crap in the carb too..Stuff still gets by the filters once in a while, but adding the $15 pressure gauge will tell a lot too. If the gauge says 3PSI and the motor still needs choke, something is clogging the carb..If the gauge is 1PSI or less and the motor needs choke, probably clogged filters and the motor is starved for fuel and the carb itself might be OK.

I had a saturated water separator filter that was starving the engine, but she was still running at 1 PSI. Couple drains of the filter bowl and things got a lot better (until it got saturated again, but at least I knew the carb was OK, and the gauge helped explain the problem being upstream). Fixing the fuel filler leak that let the rain water in to the tank in the first place, really helped the situation.
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Old 04-29-2019, 10:04 AM
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Sometimes the source of crap in the carb is the filter itself. One listmate a while ago cut open a metal polishing filter and found that the metal was corroded into a white powder, that plugged up his jet. How old is your polishing filter?
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Old 05-02-2019, 01:53 PM
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Thanks for all of the suggestions.

I installed a fuel gauge after the polishing filter (which is after the pump) and I am getting 4.5 PSI. I turned the idle air screw in about 1/4 turn and it just ran in gear at the dock flawlessly for 15-20 minutes.

Now I'm noticing a hole in the side of the fuel pump that is oozing out a viscous liquid. Wish I had ordered a new one last week when I thought of it. Planning to go out for the weekend tomorrow. Any suggestions for a pump that I might be able to get locally that I could make do with?
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Old 05-02-2019, 04:07 PM
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Originally Posted by Cityhix View Post
Any suggestions for a pump that I might be able to get locally that I could make do with?
When I first got my boat it had this Facet AUTOMOTIVE pump.
I used it for about 2 months before replacing it with the marine version offered here on MMI.

Napa seems to have it readily available. Not sure of your area.
https://www.napaonline.com/es/p/BK_6101078
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Old 05-03-2019, 12:36 AM
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FYI - I used the same Facet "cube" pump as shown for over 20 seasons. Couple of friends of mine use the newer "posi-flow" design. Changed it out last spring with a new cube when I had some fuel issues [ethanol/water/crud etc] and they were readily available for on line for $40-50 bucks. Various model numbers have different pressure ranges which are not available in store stock - believe I bought 2-4psi range and the pressure gauge shows a steady 2.75 +psi, engine runs fine.
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Old 05-03-2019, 12:01 PM
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Carb bulliten

When rebuilding or cleaning the carb VERY special attention need to be paid to the "emulsion well" seal. The emulsion well is in the center of the bowl and seals with the bowl gasket. If and many are the bowl halves are not pristine this seal in the center does not seal. Any leak will have adverse affects on fuel delivery especially making the mix lean at idle and even full throttle. It is a must that the gasket seals in the "center".

Dave Neptune
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