Force help needed BAD !!!

[splitshot]

I'm working on a 1997 40 hp force for a guy and it has a miss at high speed only runs great otherwise idles perfect great compression ...carb is spotless inside...when running wide open it sounds like -----da---------da-------------da with about 15 seconds or so in between misses...i hooked up a timinglight to each plug while running up river wide open and from half throttle to full throttle the light has a change in it kinda like it misses a beat so to speak

another guy did work on the motor and "adjusted the carb" because it wouldnt idle..but now it idles good but misses at high speed...the plugs look kinda rich to me but i'm not sure, definately dont want to lean it out...the third picture shows the only screw on the carb and i'm guessing its a mixture screw ?? turn it in = lean turning out = rich



top plug

Bottom plug

screw

 

[john from md]

Re: Force help needed BAD !!!

It is definitely too rich.

I don't know anything about a 40 size engine but will try to help out.

First thing to do is reset the mixture screw to 1 1/8 turns out. Next, go to the FAQ area of the maintenance section of this forum and learn how to do a decarb. Once you are comfortable with what you have to do, decarb the engine. Afterh you decarb it, readjust the mixture screw for best idle.

Let us know if it runs any better with a decarb.

Regards,

John

 

[splitshot]

Re: Force help needed BAD !!!

alright thanks alot !!! i have done decarbs on johnsons before so it will be no problem thanks again, i'll let you know how it goes