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Discussion Starter · #1 ·
I took my sled out the other day after a top end rebuild. I put on about 6 miles at about 1/4 to 1/2 throttle when it started to sputter.

Within a couple of minutes it would hardly run.

I could ride slow but it I tried to accelerate it would start to backfire. Every once in a while it would backfire then run fine.

I rechecked the airscrews and cleaned the carbs ( I had cleaned them a few weeks back). Compressionis is 135 per side.

Could it be electrical?
I did mix some oil in the gas for the break in period. I was going to try straight gas tomorrow.
 

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to me it sounds like the carbs or the plugs.ck the plugs.plan on going through a few run premix along with the injected oil as well.I run the same way when I do rebuilds and you'll foul plugs.the reason I don't think electrical is because it runs ok at a lower speed,it's when you want to accelerate is when it happens right?which means more gas and oil............just my 2 cents.

830
 

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I am Spartacus
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machz830 said:
the reason I don't think electrical is because it runs ok at a lower speed,it's when you want to accelerate is when it happens right?which means more gas and oil............just my 2 cents.

830
It should also mean more air...But you're straining the ignition system more at higher RPM's. It's either WAY rich or misfiring..., thus the backfiring.
 

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Discussion Starter · #5 ·
When I got it, it needed a top end rebuild. I was told the one carbs clogged but it still ran eventually frying the rings. When I took the carbs apart they were a mess. In the process I noticed he had a 280 and 270 in for the main jets. The manual calls for 290 and 280. I put it back to stock.

Is it possible it came with the smaller jets and the manual was wrong (I even had a dealer check)? Should I risk dropping back down? I did open the air screw a little more in attempt to lean it out
 

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Discussion Starter · #7 ·
They were browm.

TO help with the break in I turned in the airscrews 1/4 turn and added premix. They were then black but dry.
 
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