Optimum Air/Fuel ratio for ski engines?

[Watty]

I'm in the process of making up a set of tuning lights that tells me if my ski is running rich or lean.

The conditions where I live change so much, it's sometimes hard to tell whats going on just by riding the ski.

Basically, it will be like a set of tuning lights that you use in go-karts, that uses a temp probe in the exhaust ports.

The initial start point will obviously be the optimum air/fuel ratio and then work up and down the scale from there.

Can anyone tell me what they think would be the best AFR for a 2-stroke ski engine? I know there will be difference in opinions here, but I'm after a starting point. Any input would be appreciated.

Thanks.

 

[Matt_E]

The best AF ratio for ANY and ALL engines is 1:14.7

 

[the only couch rider]

why not just buy an a/f meter for a carb'd application, get your a/f dialed for the motor and leave it at that?

 

[Watty]

Ok, cool. Thanks.

Yeah, I'll be using another oneto get this one set up correctly so it is accurate, but I thought maybe ski engines may like a different AFR for whatever reason.

I should have this finished off within the next couple of days. It should be handy for tuning the top end, well, keeping the mixtures correct fot eh given compression/timing advance.

I have mates that use them on bikes and karts and it certainly takes a lot of the guesswork out of them.

 

[Matt_E]

I should add that 1:14.7 is the optimum volumetric combustion efficiency. While it does hold true for all engines, do not forget to compensate for the added oil.

 

[the only couch rider]

use the stand alone a/f gauge like the ones listed below..... it will save you some fab time i would use any of the one's below

http://www.performancecenter.com/products?category_name_sub=Gauges&sf4=Search+By+Gauge+Type&universal=0&sf5=Air%7EFuel&category_name=Gauges+%26+Dash&clearance=0&step=3&sf6=Aem+Gauges

http://www.performancecenter.com/pr...+Dash&clearance=0&step=3&sf6=Autometer+Gauges