Snowmobile Fanatics banner

1 - 12 of 12 Posts

·
Registered
Joined
·
38 Posts
Discussion Starter #1
I have a 1996 Polaris XCR 600. It was starting in one or two pulls when I first got it and it stayed running fairly easily. I haven't done anything to it, and now it starts hard and when it does start, it doesn't want to run for longer than about 10 seconds or so. A friend and I pulled off the carburetors and they were totally clean, the jets are at 160, stock size. The only things I can think of to explain this is that my friend said the carbs look like they were overbored, they look like they have been machined out. And the other thing is when I got it, it was about 40 degrees out, and now it's more like around 20 to 10 degrees. Does anyone know what this could be?
 

·
Registered
Joined
·
328 Posts
I am not sure if this particular mikuni carb has one, but check to see if the piston in the carb has a needle on it that goes all the way down into the resivoir. If it does it should have a ring around it to hold it in place. Try raising it or lowering it. If it does not have one and it should than that is your problem. Hope this helps
will
 

·
Registered
Joined
·
8,842 Posts
does it do this just when its cold? or wont let it get warm? an engine needs four things. fuel air spark compression.
it first sounds like a fuel problem. are the chokes adjusted?
do you have a filter, either in the tank or before the pump, is it good?
is this the first start of the year? is the gas from last year? was it stabalized?
i would check the fuel filter, put in fresh gas, new plugs and give it a try. you might have to run for a while to get the old gas out of the system. play with the choke once it is running see what makes a difference. thats should be a place to start.
 

·
Registered
Joined
·
38 Posts
Discussion Starter #5
Well, it does it when it's cold, but I can't get it running long enough to see if it will run better warm. The chokes are adjusted, and the slides are adjusted. Filters are good, I've put new gas in it, and plugs.
 

·
Registered
Joined
·
3,188 Posts
Well, i have one idea, but i've been avoiding it. It's rather grim.

I had a 96 xcr 600 and the crankshaft went out on me. I was flying along at WOT and suddenly the engine died, as if someone hit the kill switch. After repeated attempts of starting the machine, it just would not run. I checked everything, but it wouldn't go. I finally asked a mechanic. We knew these engines were notorious for twisting cranks. The first thing we noticed was that the clutch didn't spin in a perfect circle. It was very very slightly out-of-round just by watching it spin. So we pulled the clutch off. Then we used a dial indicator tool (i think thats the name?) to measure the tolerance of the crankshaft and it turned out to be way out of spec. That's how we determined that the crank had twisted. I brought it to a crank-shop place that does repairs on crankshafts. They looked it up in a book to see what they could do about it, then told me that they DO NOT work on the crankshafts on these particular engines. They said many of them have come to the shop, but they always turn them away. He said "those cranks are nothing but trouble".
I did, however, find a specialty shop that CAN repair it, but he had a 9 month waiting list!!! So I put a used one in for $350 and it ran perfectly again. It felt like a ticking time bomb just waiting to go off, so I sold it. Never-the-less, it was still a fun sled to drive with alot of speed, but i just wanted to get away from it.

I'm not saying that is what's wrong with yours, but its not impossible.
 

·
Registered
Joined
·
135 Posts
maybe the needle and seats are bad. The jugs could be full of gas. Look under the exhaust on the bottom front of the jug. The is a little bolt, take that out and see if any gas comes out, do all 3 holes.

Runner
 

·
Registered
Joined
·
287 Posts
Pilot jets, pilot jets, pilot jets. Replace them with new.
 

·
Registered
Joined
·
2,729 Posts
Check the needles and seats in the carbs...make sure they are stopping the flow of gas. i usually take a clean peice of 1/4" gas line, attach it to the carb and blow through it while moving the float arm up and down to check this. Also...make sure your belt deflection isnt set too tight....if its too tight it will drag on the primary clutch and make the sled VERY difficult to start if you can get it running at all. I had this problem on an older sled of mine, but it is something to watch out for.
 

·
Registered
Joined
·
246 Posts
Did it run when you parked it last year? If it did your carbs might have a bit of varnish on them. Try running some injuctor cleaner in your gas. Try 1/3 can to a tank of gas. You will have to run it for a while but it will break it loose. I made the mistake of not shutting the gas off on mine and it took about 30 miles for it to run right.
 
1 - 12 of 12 Posts
Top