speratic speed

[Brandenton]

I have a 1984 90 horse, Chrysler model 908V4B, at idle it runs great. Once i give it gas, it starts to have speratic speed changes. Even at WOT it only has about 2000 RPM's and doing less than 10MPH and it jumps around. I checked compression and spark and both were good. I replace the fuel diaphram and gasket, as well as fuel line from the gas tank to the motor and the carbs are tuned as per the chrysler manuel. Anyone ever have any problems like mine? If so, what was your resolution? Any help would be great. Thanks.

 

[additup12]

Re: speratic speed

I am having the same problem with a 1989 85 hp. It started to occur after accidentally running the gas tank dry on gas. After I refuled it started to have the above discribed problem. Starts fine, idles fine, goes into gear fine, even starts to accelerate fine. Once i get to plaining speeds, the power sort of dies off for no reason. I have done the above as well as degummed the carbs.

Does anyone have any idea what may cause this?

 

[GrindKore]

Re: speratic speed

These symptoms may be related to a number of issues, however it is also possible air being sucked in to the fuel delivery system and causing the motor to run lean at higher RPMs. Check your fuel line clamps before and after fuel pump. I had similar problem, turned out the fuel line between pump and the carbs was cracked.

 

[Brandenton]

Re: speratic speed

I did replace every bit of hose from the gas tank to the motor, all of it is brand new. I did go back and double check that all the clamps were tight. It runs fine with the muffs on it, but I wont be able to get the full results until I get it back to the lake.