[picklekx100]

i have a 1979 skidoo everest tein cylinder single carb. Nad im troubles with how its running it start great and evertything but it wont wind out. I think it might be the spark plug coils or the carb needs some adjusting. Some one please help.
Dylan

 

[Bman]

Do the plugs look like they are burning too dark or too light? Before you mess with the carb on that old sled I'd be checking more on the drive line. Sounds like friction is holding it up ie clutch/belt setup. Can you pull the track through by hand?

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I think.... therefore I sled
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Two '94 Indy XLT SKS

 

[picklekx100]

The sled did run good for about 3 hrs and the plugs are brand new. I will get the friction and see if i can pull the track through.

 

[picklekx100]

Is there anything else tht could be wrong?? please help!!!!!!!!!

 

[TriumphoverU]

by wind out i assume that you mean it wont reach top speed. I dont know if you mean the engine is not reaching top rpm or if you mean you just aren't moving very fast. My moms 77 ski-doo olympic had a problem where the engine ran great and rpm's wound all the way up but the sled wouldnt move very fast. It turns out on this sled the track drive sprockets had seperated. The rivets holding the sprockets together had rusted away and the sprocket no longer was turning with the drive shaft. The sled still moved but not very fast, cause the sprockets were slipping.

I would also check for seized bearings in the idler wheels and make sure the track rotates freely. Otherwise check the main jets in the carb to be sure that it isnt partially plugged.

Polaris is my way out - Other people just use a door.

 

[picklekx100]

the engine wont build up rpm's. it stops in the midrange. anyway other opinions.

 

[Ludwig]

Does it build up if you lift the track?
Do you ever smell belt when you're trying to hammer it?
Do you put stabil in your gas? Do you maybe have a varnish problem?

 

[Skrplyr23]

Usually when it sticks in the midrange its because its not getting enough gas. I would think that this is a carb problem that can be adjusted.

 

[picklekx100]

I checked the carb everything is ok there. it did run good and then it just stopped building rpms well my bro was riding so i dont think its the gas or the carb.

 

[Ludwig]

Okay, not gas or carb...
Does it still jump off the line like it did? Did the throttle cable slip?
Are both plug wires on good?
Did the little wire between the coils break?
Does it run better before it really gets warmed up? -could be a bad coil
What color are the end of the plugs?
Are the right plugs in it? Wrong heat range plugs might foul quickly and do this.

Does it start okay? Idle good?

 

[picklekx100]

I am checking the compressin any one know what the cylinder compression should be around on thsi sled its a 340 twin cyhclinder.

 

[Ludwig]

I don't know what the actual number should be, but make sure they're withing about 10% of each other and that they don't go UP if you squirt some oil down the cylinders.
If they go up once you've shot oil down the bores you'll be needing rings. If they're more than 10% different, the low one probably burnt a valve. Or the head might be cracked.

 

[Skrplyr23]

that year and that size engine, anything lower than 130 is bad i would think. my 1978 scorpion sting 440 pushes about 139 and it runs like a top.

 

[picklekx100]

Ok my sled is pumping about 120- 125 psi right now. each of the cylinders push the smae pressure. is this to low?

 

[Ludwig]

I don't think that'd be too bad. The Everest isn't a race sled after all. Maybe I'll buy a tester and try my '76 TNT, mine also has the 343, they should be similar.
120 would be fine in a car, too much more and you'd need higher test gas. I dunno if its different on a 2 stroke.

 

[picklekx100]

I took my engine out fo the sled and took the top end apart. everything cjecks out good all bearings are tight pistons have a little carbon on the top of them but nothing major. So now im leaning towards the ignition.

 

[Skrplyr23]

2-strokes are a higher compression engine and always have higher compression. This is true on all 2-strokes. i am kinda guessing what the compression should be on that old of an engine, but i know my older sled are all running about 140, and all the mechanics i work with if its below 130 its a little low. But that is on my machines.

 

[Ludwig]

Okay, dangit, I'm gonna have to get a tester and try it on mine. I still think the compression can't be all that much higher and still use regular gas without punching hole in pistons on a regular basis.

Picklekx100, without you passing on information like the plug color we can go around all day.
Your plug color will give alot of information about whats going on in there.
Almost forgot to ask, what plug are you using?

 

[picklekx100]

the plugs are burning a little dark indicating a mixture to rich. the sled ran good for roughly three hours. then it stopped revving out past the midrange. then yesterday it stopped starting. i use ngk b9hs I think. im leaning toward spark plug coils right now or spark plug caps. yes the spark plugs have been replaced.

 

[Ludwig]

Hmmm, for my '76 TNT with the type 343 you're supposed to use an 8something.
If it ran good for 3 hours, then lost midrange, then wont start at all, AND the plugs are black.... Hmmm,
Do you get spark at all?
If you take the plugs out, put them back on the wires, they them across the engine so the metal part of the plug contacts the metal part of the engine(important) and crank it over, can you see spark across the sparkplug gap?
What color is it? Weak and yellow would indicate a bad coil for that side, bright and blue would be good.

I'm going to lean toward still saying its a carb problem, but the spark test will tell alot. Don't replace your coils until you've tested.