89 Force 85hp rough idle

[Trum008]

Engine ran fine then one time cut out on me. cleaned carbs, replaced fuel line and fuel filters. finally, Replaced "the problem" fuel pump diaphram which was ripped. that fixed the problem....for a while. ran great for a few outings now i have a very rough idle and the engine runs great when in gear but when I pop it back to nuetral the engine cuts out. all spark plugs are oily. adjusted the mixture screws and idle setting a bunch. It seems to idle at different RPMs all the time then slowly decrease RPMs till the engine dies. Gets worse every time i take her out. stumped. A few notes: u get zapped by the spark plugs even with covers on, seems to be leaking fuel out of the lower part/unit of engine, small leak in water cooling exhaust, oil on spark plugs, gas in inline fuel filter is orange before pumping bulb when sitting for awhile before pumping bulb to get the ussual blue fuel, battery doesnt charge well when engine runs. I know it has many symptoms but the carbs should be clean and dont know where else to look. Could this be a lower unit problem? Also, I seem to use too much fuel when out on the water leading me to believe its leaking excess fuel. please help!

 

[jerryjerry05]

Re: 89 Force 85hp rough idle

Sounds like the fuel pump wasn't assembled right.Or the gasket behind it might be on wrong.
When you had carbs off did you check the reeds?
Do a compression test.
Spark zapld boots,replace.Check all wiring connections.
Get a carry tank with fresh gas and oil.Unhook the main tank and run it on the spare.See how it runs then.Orange gas:Ethanol in your area?(profile)
I doubt the lower would be causing any of these problems.J

 

[steveclv]

Re: 89 Force 85hp rough idle

Everything he said...plus

Sounds like an over-rich mixture possibly an incorrect float level in the carb bowl or a leaking float. The fuel you are seeing in the lower unit is probably unburned fuel from the exhaust water - when you are running in gear your engine is not using the idle circuit, it's using the main jets which are fixed and non-adjustable. When it drops back to idle, the idle mixture circuit is the main fuel control and as it's far too rich it's loading up the motor with more and more fuel which eventually chokes it.

So start checking your entire fuel system from tank (the idea of a carry can of fresh fuel/oil is a good one) through the fuel pump to the carbs - looking for air leaks, blockages etc and then check the idle mixture screws on the carbs and the float levels. If it's carbs then it's probably just one that is affected which is why it idles and then dies over time.

 

[Trum008]

Re: 89 Force 85hp rough idle

Thanks for the input guys! I needed to make sure that the lower unit (like a gasket or something like that) wasnt the problem. I did check the reeds and there is 4 on each cylinder. one or two of the reeds were sticking so i should probly change those reed plates but someone told me that wouldnt make too much of a difference. also i think that maybe i need to clean the carbs again. one of them I am expecially skeptical of like you said that could be why it eventually dies out. I just dont know how they could have gotten that dirty in a few trips. I would think that the filters would help with that. Another note is that one of the carbs is sucking in alot more air than the other 2 when the intake is off and i put my hand up to them. this carb is the healthiest of the 3 i think and the other two need to be bringing more air into the mixture. my idle mixture screws only seem to run right when they are almost all the way rich which i dont like. Ill try that spare tank too. Any more suggestions?

 

[jerryjerry05]

Re: 89 Force 85hp rough idle

Do the comp test.Run it on a spare.Then go through the fuel system.
You don't say where you live(profile) so,Ethanol is a BIG problem with older hoses and gas lines.
It's delaminating the inside of the hoses and melting rubber and creating deposits in the works.J

 

[Trum008]

Re: 89 Force 85hp rough idle

I updated my profile but i live in Clearwater Beach, FL. And yea we do have ethanol in the gas except for one gas station thats really far away. I have mostly new gas lines though and always use ethanol treatment in my gas (startron enzyme fuel treatment). I'll try that compression test too just dont have the gear to do it. Its just weird that the engine ran perfect for awhile after replacing that fuel pump diaphram and now its got this idle problem out of nowhere