Mixture screw

[allymoss]

I bought a colortune device to adjust mixture to being perfect.

But, how do you adjust the mixture on a mercury 40hp blueband twin cylinder. serial no. is 9251545

I have looked myself and looked on mercruiserparts.com but cannot find a mixture screw.

 

[hkeiner]

Re: Mixture screw

If your carb looks like the one in the picture below, then the idle adjustment screw is #24. The high speed jets (#27) are fixed in size and are not adjustable.

By the way, I have always been curious whether the Colortune device really works for a 2 stroke outboard motor or if it is just a bunch of hooey and not useful for this application. If you end up using it, report back on how effective it was for adjusting the low speed idle jets.

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[allymoss]

Re: Mixture screw

ok thanks. I will report back on how the colortune device works.