idles rough

[grogan604]

hello i have a 40 hp force engine that i am having idle problems with put a water pump on new plugs fuel filter.it runs great on topp end but when u bring it back to idle it starts chugging and sounding like its loading up or flooding also smells like exhaust in cowling area pulled plugs found lower 1 wet and top one black deposits on it any help would be greatly appreciated thanks

 

[eurolarva]

Re: idles rough

Hello Grogan and welcome to Iboats. You are going to want to have a compression test done and a spark test done. Something is wrong with that lower cylinder. Hopefully it is just a head gasket but it could be more severe.

 

[jerryjerry05]

Re: idles rough

Do the comp and spark tests.And always check for water in the tank.Then check this.Front top of the carb top screw. Start motor then back screw out.If it makes a difference then turn it back in till messes up then back out till it stops then 1/2 turn out .Jerrry

 

[john from md]

Re: idles rough

Buy a Clymer manual and read the part on adjusting the carb. It may be only a mixture screw adjustment. If the carb hasn't been cleaned in a while, you should consider giving it a thorough cleaning.

Hope this helps,

John

 

[grogan604]

Re: idles rough

i think my engien might have an exhaust leak i noticed exhaust fumes in the cowling and when i pulled off the cowling it started idling higher like it was finnaly getting fresh air to breath could it be the lower seal between the power head or the exhaust manifold gaskets?

 

[sweezy722]

Re: idles rough

It could be the exhaust gasket just as you suspect. I had the same problem back in the spring. When I got it apart my adapter plate had a crack in it. Your symptoms sound the same as mine did. You will need help lifting the head off and putting it back on. It is not that heavy but you do not want to risk dropping it.

 

[grogan604]

Re: idles rough

I Managed To Get The Exhaust Manifold Off And Found The Seals To Be Ok But However Directly Under The Manifold At The Spacer Plates I Found A Gap In The Seals Big Enough To Put A Razor Blade Through,i Ordered The Parts.so Tonight I Start Pulling The Powerhead,does Anybody Think I Should Replce The Headgasket While I Have It Out Or Any Other Seals Or Matiance I Should Do With It Out?

 

[mthieme]

Re: idles rough

I would start with carb adjustments and/or cleaning too before tearing apart the powerhead.