Won't idle

[Rabbitdawghunter]

Just finished carb rebuild and water pump on 1986 50 HP. Will idle ok for about 2 minutes and then slowly starts to die out. Primer bulb stays firm and pumping the primer bulb does not help. When I activate the choke it will pickup.<br />I know that its a lack of fuel issue. I'm about 99.9 percent sure everything was done correctly with the carb rebuild. I am leaning towards the crankshaft seals, probably the lower ones because I don't see any residue coming out around the top of the crankshaft. I am running the engine on the muffs, would the lack of back pressure cause this symptom?

 

[Harker]

Re: Won't idle

My manual says to set the idle while in the water in gear so there is a small load against it. Check all the lines also where they hook to the carb and make sure they aren't split allowing air to be sucked in.

 

[Rabbitdawghunter]

Re: Won't idle

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[Rabbitdawghunter]

Re: Won't idle

There is no lean pop or cough that you ususally see when there is an air leak, don't think that is the problem. Everything is reasonably new and tight.

 

[fireman57]

Re: Won't idle

Have you checked the fuel pump diaphragm for small hoels, tears, or waviness? If it is weak it will cause the symptoms you describe.

 

[CaptainPuget]

Re: Won't idle

It could also be a sticky needle valve in a carb not allowing the bowl to fill.

 

[fireman57]

Re: Won't idle

I assume that he can run wide open with no problem. It just shows up at idle. Is this the case Rabbitdawg?

 

[tabbott]

Re: Won't idle

Resetting the low idle screws on mine fixed a similar problem.

 

[Rabbitdawghunter]

Re: Won't idle

Yes, the problem is only at idle, it uses vro that has been converted to premix. If it has adjustable idle jets the are covered by a welch plug. I soake the carbs for about 3 hours, blew them out with air and then verified with spray that passages to intermediate and idle ports were open.

 

[Rabbitdawghunter]

Re: Won't idle

Captain Puget, there were brand new needle and seats installed with the carb rebuild kit.

 

[fireman57]

Re: Won't idle

Did you ever check your fuel pump?

 

[reeldutch]

Re: Won't idle

I think your needle gets stuck.<br />did you check your float settings?<br /><br />i had the same problem with my v4 and changed the whole fuel system.<br /><br />now it runs fine.

 

[Rabbitdawghunter]

Re: Won't idle

What do you think Joe?

 

[Rabbitdawghunter]

Re: Won't idle

Fireman, if it runs ok at WOT, I had pretty much dismissed the fuel pump as part of the equation.

 

[Rabbitdawghunter]

Re: Won't idle

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[rabidfish]

Re: Won't idle

(My opinion) Your engine is worn out. It's not starving for fuel, it's loading up. It can't push the air/fuel charge into the combustion chamber, so it looks lean.<br /><br />Try this: Tilt it up while idling. ( or don't back it in all the way) Make sure the two exhaust ports on the back, just under the cowling are out of the water by at least an inch.<br /><br />Then let us know how it runs.<br /><br />I haven't seen youe engine, but i have seen hundreds like it, and dozens doing just what yours does.