'89 50hp bad idle

[TheFormerlives]

Its a 50hp Force. After sitting around for a week it'll start right up and idle nice and smooth, but if I let it idle for more than 2 or 3 minutes it'll cut out. Then it'll be hard to start back up and even harder to get into gear without cutting out. Once I get it started and in gear it drives fine, WOT is great no problems. But as soon as I bring it back down to idle speed (in gear and neutral) it'll cut out again. Bulb gets soft but not flat. Pump the bulb and she gets good and hard again but will still start rough.

I replaced all fuel lines, fuel pump diaphram, cleaned the carb bowl. Spark plugs are 1 year old and aren't fouled too bad. Fuel/oil mixture is correct, compression is 120 on both cylinders. Any suggestions guys????

 

[TheFormerlives]

Re: '89 50hp bad idle

ttt

 

[TheFormerlives]

Re: '89 50hp bad idle

Somebody....anybody?

 

[john from md]

Re: '89 50hp bad idle

It's possible that you have sticking check valves in your fuel pump. The key indicator for this is the bulb going soft and the engine cutting out. You can pull the pump and gently press the center spring loaded portion of the check valves with a ball point pen. Do it a few times and see if it sticks. Do it gently as your fuel suction is only about 2 pounds.

Another possibility is that your fuel recirculation system is clogged. On a late50 horse engine, this system is the two small rubber lines near the fuel pump. At either end is and orifice and they need to be cleaned out with Carb cleaner.

On the early model 50 hp you have one rubber hose on each side of the engine going to orifices at the ends. Additionally, you have a plate on the right side of the engine that the one hose goes to that contains reed valves that allow excess fuel to be routed back for reburning.

If this system is clogged, you will get fuel build up at lower speeds which will cause the engine to run rough and shut off. It does not cause the bulb to go soft however.

John

 

[TheFormerlives]

Re: '89 50hp bad idle

Thanks John, that was very informative and I'll be looking into those things that you mentioned!