Snowmobile Fanatics banner

1 - 16 of 16 Posts

·
Registered
Joined
·
17 Posts
Discussion Starter · #1 ·
'91 Polaris 500 LC Twin inside a '94 Polaris body.
It is easily started but dies out after about 30 seconds or so. It does the same thing while idling or throttling. It just started doing this last night, my friend and think it is the CDI because when it is running it sounds fine, then, it dies out as if the kill switch was being pushed. We took out the plugs to observe the spark, they seem to be weak, I don't know if that would be the problem though because it does start. We observed his '97 Polaris' spark and it seems to be significantly brighter and it runs at a lower wattage-180, I guess mine is 200. Yes, there are brand new plugs in it. Anyone run into this kind of problem? Think it's the CDI?
Another thing is that the exhaust has a bunch of holes in it at the "Y", sorry I don't have the technical terms but this "Y" is located directly off the engine and it's got a bunch of holes along the seam, but, I doubt this would be where my problem is.
View/listen to what I mean here:

http://www.youtube.com/watch?v=04TyhhYWq4g
 

·
Registered
Joined
·
1,850 Posts
First off, fix that y-pipe. That's going to kill that motor.

I don't think it's the throttle switch. Towards the end of the video, the sled started to die and he went to wide open (or close to it) and it didn't even try to come back. Do you know of anybody with the same cdi you could try? Hate to see you just throw money at it hoping the problem goes away.

After it dies, how long do you have to wait until it fires up again?
 

·
Registered
Joined
·
17 Posts
Discussion Starter · #4 ·
7
Hangman said:
First off, fix that y-pipe. That's going to kill that motor.

I don't think it's the throttle switch. Towards the end of the video, the sled started to die and he went to wide open (or close to it) and it didn't even try to come back. Do you know of anybody with the same cdi you could try? Hate to see you just throw money at it hoping the problem goes away.

After it dies, how long do you have to wait until it fires up again?
Not long, been firing right up. Today I ran it about 3 mins at 3500 rpm, it would sputter and bog after a minute but since rpms were up it remained running. I'm starting to think the exhaust has something to do with it.
 

·
Registered
Joined
·
105 Posts
the y pipe is not your running problem-guaranteed!i had one split 5 miles from home once and drove it home that way!as far as model parts changing goes-pretty much all the fuji 500 electrical parts are compatable except the first year-89.those had a indy 400 ignition which i think was 2 males and a female plug to the cdi.i really think it sounds like your throttle switch or maybe a partially grounded kill swith.just unplug the 3 wire connecter coming from the throttle block and see what happens.if its not that at least you have eliminated that.
 

·
Registered
Joined
·
17 Posts
Discussion Starter · #7 ·
How do i determine if my engine is a 500 sks, classic, or sp? Like i said i know its a 500 but its in a '94 600 body. Im trying to get the exact model identification.
 

·
Registered
Joined
·
17 Posts
Discussion Starter · #8 ·
nevermind that last post to anyone who cares. I got a y pipe and cdi, putting them in this weekend but I doubt it is the problem, I bet i will see the same weak little spark.
 

·
Registered
Joined
·
17 Posts
Discussion Starter · #9 ·
nope, wont start, buddy told me to try a compression before I keep going, my compression is around 60psi, is that low? new cdi is in but still same old weak spark, Im glad I bought this no good peice of shit that ran fine for a week.
 

·
Registered
Joined
·
393 Posts
60 psi is not good at all.Not sure but I,m guessing should be around 125psi.Sounds like its starving for fuel to me.I,d check all the lines including the one in the tank.Also if the compression is that bad in both cylinders it may not pulse the fuel pump very well(I,m assuming its a carb sled).Still doesn,t explain your weak spark.As far as cdi,s usually there either good or bad most of the time.Not acting up sporadically.
 

·
Registered
Joined
·
1,850 Posts
How many times did you pull it over to see 60 psi? Just wondering, but doesn't explain the weak spark.

Have you checked the connectors at the coils for corrosion, dirt, or being loose?
 

·
Registered
Joined
·
17 Posts
Discussion Starter · #12 ·
Pulled it over a few times but since then I learn that the throttle should be open to test compression? Things u learn... ill try again. I knew going in its probably stator. New caps new cdi new plugs, soaked plugs after a round of trying to start, new(replaced) y pipe so solid exhaust. I'm eliminating everything around it I think. All wires seem fine, and I can see/smell fuel go through system. By the way, is fuel supposed to drain out of the bottom of a carb after a bunch of pulls?
 

·
Registered
Joined
·
1,850 Posts
Torr58 said:
Pulled it over a few times but since then I learn that the throttle should be open to test compression? Things u learn... ill try again. I knew going in its probably stator. New caps new cdi new plugs, soaked plugs after a round of trying to start, new(replaced) y pipe so solid exhaust. I'm eliminating everything around it I think. All wires seem fine, and I can see/smell fuel go through system. By the way, is fuel supposed to drain out of the bottom of a carb after a bunch of pulls?
Shouldn't drain any fuel at all. Maybe a stuck float or bad needle or leaky bowl gasket.

The reason I asked about the compression, is when it was running good, it sounded strong. But, it's kind of hard to tell on a video.
 

·
Registered
Joined
·
17 Posts
Discussion Starter · #14 ·
update: my brother in law (who knows about these things) says compression is fine and cheap autozone rent-a-gauge is junk, say it has to be stator, i bought a stator and guess what?? bright blue spark, started on first pull! then, idled down and off, wont start again. im angry. Im thinking compression is bad and was running on weak spark entire time until compression finally said bye bye. to the other guy i pulled it over many times to see hwo high i could get guage, topped at 60 psi but didnt stay there at all, bro in law said guage is junk bc needle is supposed to stay there a second. Im really ticked at this thing, it ran fine until the day i wanted to take it on the trails, that was weeks ago and $200 later im still not running.
 

·
Registered
Joined
·
17 Posts
Discussion Starter · #15 ·
I just dont get it, it started fine last night right after I got the new stator in, now its doing the same thing, turning over and turning over without starting, the only difference now is that i have spark, good i guess, but worthless without a running sled. I have absolutely no idea how to re-do (rebuild) the seals and gaskets and such. Im going to do compression test again with different gauge and see if it get better than 60psi, but with my luck I wont and that will probably identify my problem, or, its something to do with carbs which are buried.
 

·
Registered
Joined
·
17 Posts
Discussion Starter · #16 ·
as closure (knock on wood) I did get the sled running, quite nicely, it was the stator no doubt but i adjusted the idle screws and that got me runnning neatly, as long as its warm it starts on a half pull, oh the feeling!
 
1 - 16 of 16 Posts
Top