24 replies to this topic

[ironfist104]

I was running way to rich so I rejeted I went down one size I was just wondering if this is the right shade of brown. or is it still too dark.

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[zekenater]

what kind of oil are you running? youre definatly on the safe side of brown if that was tested at WOT

[bknight187]

What size did you step down too? What size did u have in there? They were jeted different depending on if they were shipped to Canada or US.

[ironfist104]

What size did you step down too? What size did u have in there? They were jeted different depending on if they were shipped to Canada or US.

I sent you a P.M.

[zekenater]

are you sure they were jetted different, in my parts manual for a 79 says a 370 nothing about usa/canada

[ironfist104]

mine 370 i tried a 340 looked greyish so i went up too a 360

[bknight187]

are you sure they were jetted different, in my parts manual for a 79 says a 370 nothing about usa/canada

I should correct myself. You are correct.......... they did not put on different carbs or different size jets on the 450 Rotax. The 1981/1982 are the 464. They come with different carbs and jets in them.

USA VM 34-258 with a 340 main, 6EJ1-3 Needle, 159 P-0 Needle Jet, and 40 Pilot jet
Canada VM 34-215 with 310 main, 6F9-3 Needle, 159 P-8 Needle Jet, and 40 Pilot Jet

I run the 340 in mine, with the needle set on the top notch. Main is 1 turn out and pilot in 1 1/8ish turns out. Here in PA we dont see temps below 20 degrees F. consistantly.

[zekenater]

thats wierd youd think the canadian carb would run the higher jet since our temps are way colder

[ironfist104]

I played with it this weekend did better I think I can go down to a 350. cuzz after playing around pulling the groomer and the ice hut I took out the plugs and they where shy of being black.

[zekenater]

i have a 350 and a 40 pilot in my uncles machine for him seems to still be tad rich

[ironfist104]

Well I dunno what next. I did a new jet a 350 down from 370, all new fuel lines, a new primer pump, a rebuilt kit in the fuel pump, pressure tested the tank no leaks,and I have 150 psi compression. I have a new belt, I checked the tracks nice fit and alignment.

So now I'm wondering what next to bring that mileage up.... Today I got 24 miles on a five gal. of gas.... the only thing that's gonna be different on the next ride is the rebuilt fuel pump.

[ironfist104]

I'm also wondering if a restricted muffler would have effect on mileage.

[bknight187]

Ok something is not correct if you are getting five miles per gallon. Yes a muffler restricted well play a roll in poor gas milage but I am not sure how much. Let me do some research I can't remember off hand how the restriction effects the expansion chamber and combustion cycle. Also post your gas milage question in the vintage section as it will have more people view it and someone my think of something we are missing. BTW sounds like you are doing a good job trouble shooting. Step by step and looking at the correct things. One other thing is I would make sure everything is moving freely. Pull the belt off, jack it up, and see if the tracks spin somewhat easy. Also make sure the track is not rubbing on anything, and the gear case is topped off.

[zekenater]

a fuel pump can leak threw the diaphrams. but at 5 mpg youd think it would smoke and sputter horribly.
does it seam like the motor is working real hard?. i would change the needle and seat and make sure the float is adjusted correctly

[ironfist104]

Thats the funny thing the dam thing pull really good when I punch it it almost feels like its lifting the ski it has no problem spining the tracks. Tonight I'll break cleaner all the clutches to make shure that there is absolutly no oil/greese on them...see if it might be slipage.