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emlesnick 08-17-2013 12:17 PM

Troubleshooting help Needed
 
Hi all Thanks in Advance. I'm at my wits end and have used up my limited knowledge. I'll try to make some sense but cant promise anything lol

Engine is a rebuilt A4 purchased 2 years ago with probably a total of less than 10 hours time on it. Last year was very short season.

Engine started running rough and would not accelerate through full range of RPMs no matter what setting throttle was at.

Engine would start and die out. Would only start and run with full choke.
I let engine sit for a few minutes and then it would start back up.

I thought maybe the Water/Fuel Separator wasn't working or needed to be changed.

I changed the bulkead mounted Racor Water/Fuel separator. I forgot to fill filter with fuel when I reinstalled.

Engine would start only on full choke and die out. Engine Very Anemic. As soon as choke was lessened it would die.

I removed Racor filter to make sure fuel was in there and it was.

I removed Fuel line at the Carb intake and jumped out fuel pump from "out going" side of Oil Pressure switch and fuel was flowing out of hose into a glass jar.

I took off the Carb, brought it home, and cleaned and removed jets as in the Video from Moyer (which was very helpful for me). The only thing I did not do on the video was use the wooden dowel.

Upon trying to reinstall Carb I could not get the Aft bolt to catch. I attempted this for a long time and finally realized threads were stripped on Carb. I got a new longer bolt that caught the last 3 good threads and seemed to work. It made a tight seal to flange and didn't protrude to hit Idle set screw.

I reinstalled Carb and Engine would not start. It turned over once on full choke and died immediately.

We tried jumping out fuel pump again to starter to make sure it was "humming" just incase I made a bad connection reinstalling. Pump was making the sound.

I tried every combo of throttle/choke/idle set screw setting to no avail.

I am unsure if fuel is getting into carb. Spark plugs seemed dry. There was a little fuel under spark arrestor according to my partner in crime.

I looked at wire that runs from the Distributor Cap to Oil pressure shut off switch. There was a lot of "goop" in fuse and on terminal end of switch. Not sure if its anti corrosion stuff or something else?

Is it possible to "jump out" oil switch by just clamping some alligator clips to top of distributor cap and to "out side" of the switch?

Any other suggestions?

I'm sure many of you out there can imagine my state of mind right now:mad:

I spent over an hour trying to get the carb back onto the flange, had to make trip off boat down to hardware store to get new bolt, etc, etc.

This engine is rebuilt and has has such little usage. I'm sure the fault lies with me somewhere but for the life of me I can't figure out what is wrong. I'm losing valuable cruising time and getting frustrated.

Thanks for any and all suggestions and thoughts

CalebD 08-18-2013 12:29 AM

1 Attachment(s)
Welcome.

A few quick spurts of ether/starting fluid into the flame arrestor and then starting the engine will tell you if you have spark; if it kicks over a few times and then dies you've got spark.
If you have spark but no fuel then your fuel pump is a likely suspect. If your fuel pump is electric the OPSS (oil pressure sensor switch) is also a suspect as well as the pump. The OPSS can be bypassed temporarily in the wiring for testing.

When was the last time your fuel tank was drained or cleaned? You could have crud in your tank if it has been there for a number of years like mine was.

Marty Levenson 08-18-2013 02:54 AM

dry plugs
 
Sure sounds like a gas related problem. Maybe you fixed the initial gas supply problem (carb and filters) but now have a new problem....

When you reattached the carb did you set up the throttle cable properly? If it is staying shut when you think you have full throttle, that would of course keep gas from entering manifold. Similarly, take off the flame arrestor and confirm that the choke is fully closed when you give it choke. Either of those cables can look right but slip.

Are you sure the carb- manifold connection is air tight now? An air leak there keeps manifold from sucking gas up to plugs. As they say, ask me how I know.

Don't forget to shut off water intake when you do a lot of cranking.

Good luck,
Marty

emlesnick 08-18-2013 09:12 AM

I will def double check cables. What does leaving water intake open do? Ill be working on this starting in an hour or two. Thanks

roadnsky 08-18-2013 10:53 AM

Quote:

Originally Posted by emlesnick (Post 72386)
What does leaving water intake open do?

If you are doing a lot of cranking in a no-start situation, be sure to close the raw water intake until you get the engine running..
the water pump spins along with the starter (mechanically driven) so it will fill up the exhaust/muffler and then can back up and dump water into the cylinders thru the manifold.

NOT a good thing! :cool:

romantic comedy 08-18-2013 11:30 AM

remember you need 3 things to run

spark
fuel
compression


try using starting fluid. see if that makes a difference.

adab1402 08-18-2013 12:35 PM

Take a deep breath
 
Start by reading the a- 4 bible under does not run . Now the. Pull your plugs keep track of the firing order . Look at the plugs wet? No ? Great , if wet set aside in the sun or get fresh plugs s Ignition switch off water thru hull for cooling closed . Install remote starter switch ,hot side of starter to starter switch on solenoid . Switch available at any parts store Napa etc . Press the button stand clear engine should crank over look at spark plug holes. Safety goggle s on ? You can do a compression test at this pt or wad a thick paper or cloth in the hole and watch it pop out cheap entertainment. No water wads pops out briskly ? Great. Lets move on . Ignition 12 volts at the coil ? Pt sys? Pop the cap check pt cap crank engine with remote starter be careful bump it till cam lobe is on pt arm gap should be no wider than the width of a small coin great watch the Pts open and close as you crank the engine notice a spark ? Good take the coil wire yes the big one in the center one end in the coil the other 1/2 an inch from a ground the block is good do not hold in hand wedge it lots of volts get a good spark ? Great. Lets move on to fuel take a plastic cup 3-4 ounces of fuel from the tank let it settle look good? Or is water or crud mixed in ? Fuel good ? Put it all back together and see what happens . Don't be hard on yourself take some time and think it through or find a mechanically inclined friend to walk you through it these engines are great soldiers but they need to be used hope this jabbering helps. Fair winds

emlesnick 08-18-2013 12:56 PM

Guys-Thanks for the replies. Waiting to see if my friend who is much more mechanically inclined than I can joine me today. Will update ASAP

edwardc 08-19-2013 11:25 AM

Sure sounds like fuel starvation to me.

I think Caleb is on the right direction. Old/dirty/water-contaminated fuel can cause all of these symptoms, and can also re-clog a freshly cleaned carb. You can eliminate that from the equation by temporarily using a portable fuel tank with fresh gas.

When you cleaned the carb, did you physically run a small stiff wire thru every opening? Carb cleaner isn't enough. You need to get a wire thru them. There are lots of strange and mysterious vents, jets, and passages inside the carb. It's easy to overlook one. And even a thin film of varnish on one of them can cause the engine to run terrible.

emlesnick 08-19-2013 10:15 PM

I think I got it
 
Well worked on this all day. Don was very helpful and patient on the phone with me. We did A LOT of diagnosing and tests. Fuel was getting to the carb but not apparently getting up into the cylinders. After a lot of back and forth I went out to get new plugs. I had the fuel hooked up a portable outboard tank straight to the fuel pump. I sprayed starting fluid in the spark arrestor and once it got going the engine ran GREAT. very strong. full range of acceleration. I think the main culprit was bad gas. I got a new fuel/water separator and fully drained the completely full fuel tank. I filled the new fuel/water separator with fresh fuel and will return tomorrow with fresh fuel for the main tank and god willing everything will work. Thanks for all the help!! I've learned a lot.

Is there anything I should add to the new fuel when I put it in the tank and in what quantity?

Thanks again guys.

Mo 08-20-2013 06:56 AM

If you don't use a full tank per year it is best to add stabilizer to the fuel when the fuel is new....if you think you will use the fuel, by all means skip it until you add your last tank for the year.

emlesnick 08-20-2013 07:57 PM

Update
 
Back at the boat today, I added new fuel. Engine started up but with original symptoms that started this odyssey. Engine will only run "correctly" with half choke. Spoke with Don and he seemed to think there was an air leak somewhere. Anyone else have any thoughts? I'm seriously just considering ordering a new carb and throwing it on there just to eliminate the carb completely. It would suck to order one and not have it work but as of now I have a brand new rebuild that I spent a lot more on that isn't working.

Mo 08-20-2013 08:27 PM

Sure sounds like an air leak and there comes a time when a new carb is in order as well ... and now may very well be the time. Your engine hasn't been run much so I'd like to suggest a few easy checks before you order a carb just in case you need something else.

Compression test...did you do one with a gauge? Need to ensure your valves are not stuck. Also, check all plugs, not just the wire spark, and centrifugal advance springs (under distributor cap plate) for rust...lubricate those.

emlesnick 08-20-2013 08:37 PM

Mo-Thanks
I changed all the plugs yesterday. Spark seemed good. I only checked compression using the old thumb over the sprkplug hole method.

Mo 08-20-2013 08:49 PM

Quote:

Originally Posted by emlesnick (Post 72563)
Mo-Thanks
I changed all the plugs yesterday. Spark seemed good. I only checked compression using the old thumb over the sprkplug hole method.

Can't rely on that compression test...It's good enough to get her to start but I screwed up big time on a friends boat last year thinking it was good. Long story short...not the exact same problem, but I was thinking fuel all the way, then went to reversing gear....finally did a proper compression test and sorted it out...head had to be removed and valves cleaned up...my mistake cost him money (I wasn't charging him but he bought lots of things he didn't need...including a carb and smaller prop)...you may indeed need a carb, however, you need to know that compression.

CalebD 08-20-2013 08:52 PM

An air leak could be as simple as a missing or compromised gasket between carb & manifold. Check carb for any fuel leaks; if fuel can leak out then air can leak in.

Removing the main passage plug from the carb and collecting the fuel that leaks out often helps burp the carb and get debris out.

Mo 08-20-2013 09:01 PM

Quote:

Originally Posted by CalebD (Post 72565)
An air leak could be as simple as a missing or compromised gasket between carb & manifold. Check carb for any fuel leaks; if fuel can leak out then air can leak in.

About 4 or 5 yrs ago I believe I had an air leak around the throttle linkage where it enters the carb. Pretty sure that's where the problem was .. but as I had a new carb on my spare engine I just put that on .... the old one is now lost in the quagmire I call "the garage".


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