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Discussion Starter #1
I bought this sled at the beginning of the season last year with 1000 miles on it. It ran well initially, but began fouling plugs during the winter. This fall after getting it out of storage, I went though about 10 plugs (old but clean) before I got it to run on two cylinders. After running a minute or two, it fouled another one. So I decided it was time to go through the carbs. They were a little dirty but not too bad. I cleaned them thoroughly, checked float levels, etc. Put it all back together and it started right up, but only running on one (the right) cylinder. Tried a few more old plugs, but still only one cylinder. Went out and bought new plugs, and it has not fired once since. I have great spark (tried two sets of new plugs), compression is 125-130 in both cylinders, and I'm getting fuel. I can lay the plugs on the top of the head, crank it over, and flames will shut up a foot in the air. But it absolutely will not fire with the plugs in. I have a good inductive timing light, but don't know how to check the timing without the motor running (and no battery). Also seems unlikely that the timing would just go out. One friend thought maybe the crankcase is full of fuel. I have let it set for two days, and it still won't fire. It's in a heated garage. Any ideas????? Thanks! Also, this sled has the HAC (high altitude compensation thing) and about 1400 miles. My other sled is an Indy 400, which runs great.
 

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Discussion Starter #3
I don't think so. I run a part-time marine repair place and rebuild a lot of carbs. I looked closely at needles, seats, and pilots, and all looked fine to me. Even if I'm wrong, it should still fire, and perhaps run poorly.
 

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Hmmmm, well the three things you need are spark, fuel, and air. You say you're getting spark, and fuel (plugs are wet, correct). Just for the hell of it, I'd check the airbox and exhaust for nests that any critters may have built.
 

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Discussion Starter #5
I did have the airbox off when I did the carbs, and it was clean. Didn't check the exhaust, so I'll do that (although I did have it running for several minutes both before and after doing the carbs). Plugs are not getting wet. Ski-doos have the plunger-primer, and it did verify it was pumping fuel into the intakes prior to putting the air box back on. Any chance this is a reed problem?
 

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Discussion Starter #6
I also tried pouring some gas into the cylinders, putting plugs in quickly, and it still wouldn't pop. This always works on outboards!
 

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your motor doesn't have reeds it has a rotary valve, and if you ever had the cover off it could be in the wrong place, one other thing to check and i am not being mean because i have did this when trying to start it but did you check to make sure the fuel valve is turned on.
 

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Originally posted by Barry
[br]I also tried pouring some gas into the cylinders, putting plugs in quickly, and it still wouldn't pop. This always works on outboards!
As it should with sleds as well. Very strange, and since you state your familer with carbs, I won't bother taking you through that whole process, as I'm sure you know it.

If the sled fired when you dumped a small amount of gas in each cylinder, but after that it died, AND the plugs were dry, I'd say:

A: Clogged jet or throttle cables need adjust ment/idle screw as well.

B: Fuel pump isn't working.....needs rebuild.

But you say it didn't even fire when you dumped fuel in the cylinders, and the plugs are firing.......I'm kind of at a loss here. Maybe someone else will have some insight into this one.
 

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Discussion Starter #9
If you're talking about those red things above the exhaust pipes, I haven't touched them. Fuel valve is on, and I pulled the fuel line on the other side of the filter to verify gas is getting though, and the filter is not plugged. No, you're not being mean! I can fix most any outboard or I/O, but snowmobiles give me fits! [:)] Also, this motor pulls hard, but always has. My arms and back are sore!
 

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about the pull in 97 they redesigned the starter rope and they have a larger diameter spool. you should have to mess with the rave valve (the red caps) has there been anything done to the sled like a pipe or a can where the previous owner may have changed the jetting? i am still thinking its a carb problem
 

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Discussion Starter #12
The sled is completely stock. It ran before I did the carbs, ran after I did the carbs (on one cylinder with old plugs), but hasn't fired even once since I ran to the auto store and bought new plugs. It may still be a carb problem, but it should fire regardless. This motor always started after hitting the primer 2 or 3 times before. The next day, I could smell gas (I had left the gas on), but didn't see any leaks from the carbs. What about the "crankcase full of fuel" theory? Ever happen to anyone? Can I upgrade this motor to the bigger spool?
 

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Discussion Starter #13
The tank was on "E" when I started all this, so I added about 3 gals of 90+ octane gas that I had in a container. That gas was maybe two months old. In my experience, not old enough to prevent firing.
 

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Yeah, I had this problem with my 97 XLT SP. My needle n seats would leak if I left the fuel switch on. It was so bad it would leak out of the carbs, into the chassis and onto the floor. If they are leaking on yours, I suppose the case could be full of fuel. On my Polaris there are three 10mm bolts on the exhaust side of the case down near the bottom. I could pull these out to drain it. Not sure if your Summit has these or not.
 

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yes you can upgrade it you will need to get the complete housing and then there is a clamp and a rubber seal and a adapter plate, if you go to www.hlsm.com you can get the part numbers
 

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Discussion Starter #17
Well, I'll think about that recoil once I get it running again. I use that HLSM site all the time for boat stuff, very handy. BTW, this is a great forum because it has active members. I appreciate all the help. Other sites you wait for two days before you get a reply.
 

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Well if what you say is true, and you are getting fuel, and spark and compression it would make sense to me that you are getting too much fuel. So I know that you said you had rebuilt the carbs but make sure the needles and seats not just move properly but also can hold pressure. After gas sits a little while pressure starts to build up in the tank if it is not vented properly and can force pressure into the fuel lines and carbs. Next make sure your chokes arent stuck open and also make sure your idle isnt adjusted too high. If the idle is too high the chokes wont work properly. These chokes require vacuum on the back side of the throttle slide to richen the mixture, if they are open too much there will not be sufficient vacuum to make it work properly. If all else fails, hold the throttle wide open and give it a few tugs to see if it will fire. As always let me know what works or doesnt work....as you know its kind of difficult to diagnose something over the internet.
 

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Hmmm, Couple of Dumb questions,
Does that year have altitude compensators?
Is it possible you have flooded the bottom end of the motor? I know if you fill them right up they won't spin, but maybe there is too much down there. Also, and I know this is a stretch, but on an old Honda trike I had years ago, I had a plug short on me. It would spark on the head when it was out, but once it was installed it would not work. My experience with sled motors is limited so sorry if these things are obvious or off base.
 

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he has a primer and no choke there is a h.a.c system, when you try to start it do you have the system hooked up and the airbox on. what jets do yo uhave in there it should be 75 pilots and 380 mains.
 
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