Over Fueling 91' 60hp rude?

[Team Lowes 48]

This motor has a rebuilt powerhead with many new parts including taking out the VRO and replacing with a conventional fuel pump. It seems as though I have check and re-adjusted 100 things on this motor and nothing seems to work. The engine smokes excessively and will not idle. If I hook up a remote fuel tank directly to the fuel tree by-passing the pump and gravity feed the carbs, the motor runs great. However, when the fuel pump is used, the motor may as well be used as a mosquito fogger. It has been like this for both the VRO and conventional pumps. The carb floats are adjusted to specs and rebuilt, a new pulse limiter fitting, reeds, prime bulb, venting checked, etc. Any thoughts on this would be much appreciated. Thanks in advance for the help.

 

[clanton]

Re: Over Fueling 91' 60hp rude?

You have photos of fuel pump, pulse hose, and fuel supply hoses. If the powerhead is new, should have 25-1 mix in tank, which would cause smoke.

 

[Team Lowes 48]

Re: Over Fueling 91' 60hp rude?

I agree with you Clanton, but my smoke is excessive and the motor will not idle at all. I have used a 50:1 mix in the remote tank and going through the pump with the same smoking results.

 

[Solittle]

Re: Over Fueling 91' 60hp rude?

AC - Do you have the OMC shop manual for your motor? If not that is the first thing. Do a sync & link for the carbs and adjust the timing. That should solve the idle problem and will adjust the fuel/air the best that it is going to get. Have you tested the fuel pump pressue?

 

[papasage]

Re: Over Fueling 91' 60hp rude?

your fuel pump could be pumping fuel through the valcum port . check diafram form a hole.papasage

 

[Team Lowes 48]

Re: Over Fueling 91' 60hp rude?

Thanks for the info. I do have the shop manual and I am on my second fuel pump and they both have read about 6 psi. I am confident that my problem may be in the carbs but I don't know enough about them. I have done all the engine syncronization and while it was running fine w/ no smoke and gravity feed, I set the timing and carbs to specifications. My only shot in the dark is the float settings as I do not have the special OMC tool for doing so. I did set the drop as indicated in the book and rebuilt the carbs and sprayed out every port with cleaner and air. I have also set the foats about 1/8" higher upside down vs. level with the carb body and this didn't help either. When I prime with the bulb it will flood a bit in the throat of the carb and I need WOT to get it started. The float pins do their job when I have it apart and blow air into the fuel inlet while upside down. Thanks again for your help.

 

[Team Lowes 48]

Re: Over Fueling 91' 60hp rude?

You are right about the pulse hose. When I had the VRO on it, it was leaking fuel through the pulse hose, that's why I replaced with a conventional type fuel pump. I have checked the puls hose and it is dry thus far.

 

[clanton]

Re: Over Fueling 91' 60hp rude?

The float is set level with the carb body, float gasket surface. You turn carb upside down, campare top of float surface with gasket surface. The engine also needs a thermostat with correct seat and pressure relief spring. The correct thermostat seat pn is in service bulletin, the correct spring is slected by instructions in oem w/p kit. The correct temp sensor pn is in service bulletin, and others. You can push the push the float needle off the seat with bulb pressure some times. I hope to be able to scan and send next, the spring instructions next week.

 

[Team Lowes 48]

Re: Over Fueling 91' 60hp rude?

Thanks Clanton, I will check the float setting once again to ensure proper setting. I do have new thermostat at the moment but have not put it on, I will go ahead with that and I look forward to hearing from you.