larger jets after rebuild

[wayneo99]

my mechanic has told me that it is typical practice to install larger high speed jets in my 1983 evinrude 115 to avoid a lean condition and buring up a piston again.

I agree but what size is the question.

the next larger size for that era looks to be the high speed jet from the 140. he says it will be fine and suggests that that be done when carbs are redone.

has anyone done this?
i have a set of 140 carbs that are 1 5/16 but he says to stick with the stock 1 3/16 and just use the larger HS jet from the 140 carbs

any thoughts from the techs here?

 

[boobie]

Re: larger jets after rebuild

I've never done that on a rebuild, just made sure the high speed jets were good and clean. Maybe somebody else on here has done it tho'.

 

[dehydrated]

Re: larger jets after rebuild

Easy enough to just pull one of your jets and see what it is go up one size for sure better to be rich than lean

 

[emdsapmgr]

Re: larger jets after rebuild

Agree with dyhydrated. If you are using oversize pistons up to .030 oversize, you can still run the stock jets. If you are running a larger 140 carb (1 5/16") carb on your 115 engine that came with 1 3/16" carbs, it's likely it may already be overfueling slightly compared to your stock 1 3/16 carbs. The larger carbs will work great on the engine, but they tend to blow more air/fuel. Your block can take some extra air, but sometimes I've had to rejet the mains downward a size or two when using larger carbs on my lower hp engines. I'd run the larger carbs and do some high speed throttle chops and check the color of the plugs. If your 115 carb had say a .0585 main jet and the 140 had a .067 jet and you just put the 140 jet into the 115 carb, your engine won't run well at all over idle. It might run fine (reliably) with a .059 or .060 jet instead.

 

[wayneo99]

Re: larger jets after rebuild

where can I find larger jets, no part numbers listed that i can find.
it seems odd that it would not run good with the 140 HS jet but with a larger carb all together it will.

 

[emdsapmgr]

Re: larger jets after rebuild

The original factory service manuals lists all the jets. See this website: outboardbooks.com or call your Bombardier dealer.

 

[dehydrated]

Re: larger jets after rebuild

www.boats .net has jets for a good price or you can check on here