Backfire when cold?

[tjello327]

Hello,
I have a 1986 125hp Force. Just about every time I start it cold, it backfires once. When I start it, I choke it for about 1-2 seconds as I am cranking it over and it will backfire once and then start and idle good. As it warms up, I dont need to choke and it will start pretty good. Is this bakfire normal or is there something with the tuning that I need to look at better.

Thanks!

 

[roscoe]

Re: Backfire when cold?

Is it a BANG backfire, or kind of like a big sneeze?

Sneeze would indicate a lean running condition, and should be remedied so as not to burn up the engine.

 

[tjello327]

Re: Backfire when cold?

If it is out of the water, it is a bang. If it is in the water, it is a sneeze. The plugs are never lean looking, always a little wet, and at idle speeds, it smokes a little. Very poor fuel economy but I think a good prop will help that. I set my mixture screws to were if they are out or in a half turn more, it wont idle very good. As long as the mixture screws are were they are at (about 1.25 turns out) it idles good. The entire ignition system has been change and like I stated before, I havent set the timing at WOT yet, I did just at idle.

Thanks.

 

[roscoe]

Re: Backfire when cold?

With that info, it sounds like you are close, but need to get the timing dialed in.

 

[tjello327]

Re: Backfire when cold?

I was out today and this thing just starts hard when cold. I have to be very careful when I choke it or it floods. The plugs dont look bad but the guy that I bought this boat from had alot of problems with it & I think the plugs may have took a beating. He said that they were new but it never ran good for him & he cranked the hell out of it trying to start it when the igniton system was screwed up. I guess that the plugs could be gas fouled? This could be the sneezing it is doing maybe?