Still wont start>94xlt tripple - Snowmobile Forum: Your #1 Snowmobile Forum

buford94xlt · 10-30-2009, 09:16 AM

i bought this sled this pass summer for 300$ not running it had the tops off and all pistons were rusted and stuck. so i bought a top end rebuild kit cleaned it up and put it together. it has good compression, i tried to start it but only flames came out of each cylinder. i found out i needed back pressure so i put the muffler on it. still nothing a back fire or two. i cleaned the carbs they were dirty but not too bad. put the carbs back on tried it nothing. i tried switching the CDI box out with the one off of my 93 xlt triple. same engine but still nothing. then i was told to get new plugs cause once they get wet they go bad. last weekend i put new plugs and caps on but again nothing. any other things you guys can think of????

**RJ Gleason** · 10-30-2009, 10:20 AM

Have you tried to prime it with a couple oz of gas in each cyl?

buford94xlt · 11-01-2009, 07:03 PM

ya i did it with gas tho not starter fluid cause i heard thats not good to use

skiboyracing · 11-01-2009, 08:26 PM

if you got compression, you got fuel, and you got spark it should fire. If not I would want to make sure the timing is correct and that it's firing in the right spot along with plug wires, make sure the wires are on the correct cylinders as well.

buford94xlt · 11-04-2009, 11:12 PM

my friends and i were thinking it was timing but we didn't know how you adjust it or what to adjust

My 96 XCR · 11-11-2009, 12:21 AM

did you replace crankcase seals?? do a cylinder leak down test on it

kevin2502000 · 11-11-2009, 01:21 AM

Are you sure the plug wires are on the correct cylinder?

tundrapolaris · 11-11-2009, 03:22 PM

Test to see if you have suction on intake side. Have someone pull it over and put your hand over each carb to see if there pulling air in. If not you may have to tear it down and replace crank seals. Timing could be an issue, but it won't be just an adjustment issue, it might be that the mag spun on it's keyway. It's not likely but it's possible. 2 strokes can have compression, but if you don't have transfer to and from the crankcase they won't run. SEALS!

mrholmquist · 11-11-2009, 04:28 PM

I agree with the flywheel thing as a possibility. It is possible someone may have been trying to free it up when the top end was seized by yanking on the cord so hard it twisted the flywheel and broke the key. If the key is broken and the flywheel has rotated on the crankshaft it would definitely explain your situation including the backfiring you mentioned.

**smallengineguy** · 11-11-2009, 04:29 PM

Remove the recoil and then take off the flywheel nut. You may be able to see if the key is sheared.

mrholmquist · 11-11-2009, 05:03 PM

Actually I would dissassemble it and replace those seals regardless. If they leak now or in the future you will ruin those nice new pistons and you will have to do the job again. I never just do a top end rebuild, always split the crankcase, check the crank and replace all seals and gaskets. Had you have done that in the first place you would have run across the flywheel key problem too.

I hate doing things twice!!

tundrapolaris · 11-11-2009, 05:27 PM

Yes i agree, always do the bottom end! For a few bucks more and alittle more time.

buford94xlt · 11-12-2009, 11:00 PM

ya i should of done the bottom end i was just being lazy and cheap but even if it had low pressure wouldn't it still start? i put my hand over all carbs and every one had suction. i was looking at the fuel pump and noticed the gas was like yellow a little so i drained all the gas and put new gas in it, still nothing. i will look and see if i sheared a key. would it still spark if the key is sheared? i can put gas in the cylinder and it fires but after about 6 pulls and all i get is a flame in the exhaust pipe. its like its not firing in the engine but in the exhaust pipe. the plug wires are on the right cylinders i checked and i did not do the crank seals. i was wondering if it could have anything to do with the little coil things the plug wire comes out of do those go bad/ could that be it? i was also told that the ignition switch could cut the spark out if it was fried and to try it unplugging the switch all together is this true? thanks for all the input guys!

kevin2502000 · 11-12-2009, 11:27 PM

It sounds like getting fuel isn't a problem unless it is too much. WHen you say it fires, do you means it starts for a second or what? Usually when the ignition coil is bad it will not have any spark unless it is heat related and fails when it gets warm. You should be able to unplug the ignition switch as a "hotwire" as it is preventing it from grounding out. Are you sure it isn't just really flooded? Pull the plugs, look at them and if they are wet dry out the cylinders. I never trust a plug that has been fouled/flooded on a 2 cycle engine. If your key is sheared it can still have spark, just not at the right spot.

tundrapolaris · 11-13-2009, 04:47 AM

Even if you have compression 2 strokes still won't run if the seals are that bad because you will not get suction and transfer. But in your case you say you have good suction. If it's firing out the exhaust ports (more of a backfire) it's one of two things-- 1. miss firing,timing. 2. It's flooded real bad,in this case you have to air it out and start with fresh plugs. You may go through a few sets before it's cleaned out. There's a few things you can do to help clean it out quicker. There are drain plugs on the bottom at the front of the block which you can blow air into if you have a compressor. Let air run into the crank for some time but not under pressure just move air around in there for awhile to dry it out. If you remove the carbs (so you don't pull anymore fuel in) pull it over with the plugs out and ignition off while blowing air in. If you can't blow air into the drain wholes just blow into the plug wholes while pulling it over. I've had to do this before because the gas was so stale it just ends up in the bottom end. If you don't want to waste money on a bunch of plugs, you can stick them in your oven for 30 min. at 300 and most times you can bring life back into them.

buford94xlt · 11-13-2009, 07:59 AM

I've heard of the drain plugs on the bottom at the front of the block before but didn't think of that. I'll drain the block and I'll bake my plugs, both sound like good ideas. the plugs are wet but only some times. i think that old gas that was in it is still in the carbs and doesn't want to fire cause it has water or something in it, so it only fires when the water has escaped it and then the gas is left in the exhaust pipe to make a flame out of it. not sure tho. i did not know they have to have good compression to run i did know that the seals on the bottom end do go out on these sleds. if the key is not sheared and i have bad compression I'll have to do the bottom end. if key is sheared I'll replace. the key being sheared sounds like my problem i did and guessing the last guy did also pull on the cord to try and free the engine when it was seized. Thanks again I'll let you know how it goes! cross your fingers.

kevin2502000 · 11-13-2009, 05:44 PM

I second the heating the plugs, I use a propane torch. I shouldn't tell you this but I also use the torch through the plug holes to dry it out. Sometimes it will pop once and thats it. I never do this in the garage and always have a heavy rag or something just in case it catches fire. Like I said, old trick with extreme risks.

tundrapolaris · 11-13-2009, 05:59 PM

Quote:

Originally Posted by buford94xlt

I've heard of the drain plugs on the bottom at the front of the block before but didn't think of that. I'll drain the block and I'll bake my plugs, both sound like good ideas. the plugs are wet but only some times. i think that old gas that was in it is still in the carbs and doesn't want to fire cause it has water or something in it, so it only fires when the water has escaped it and then the gas is left in the exhaust pipe to make a flame out of it. not sure tho. i did not know they have to have good compression to run i did know that the seals on the bottom end do go out on these sleds. if the key is not sheared and i have bad compression I'll have to do the bottom end. if key is sheared I'll replace. the key being sheared sounds like my problem i did and guessing the last guy did also pull on the cord to try and free the engine when it was seized. Thanks again I'll let you know how it goes! cross your fingers.

Ok im confused, did you say you put new pistons and rings in, and i hope you honed it out? You can still have good compression and not have transfer. The bottom end seals do not effect compression, only fuel/air transfer.

tundrapolaris · 11-13-2009, 06:04 PM

I forgot something. This may be a dum question, but did you put the pistons in the correct way? This motor is a piston port not reed cages, correct? On piston port engines it's very important to install piston correct because the skirts are different.

buford94xlt · 11-15-2009, 12:08 AM

alright so i tested the compression and it sucked like 30 across. so i ripped apart my engine and its not clean at all but besides that does anyone know what the off set for the piston rings is???and what is the torque on the jug and heads????? o and the key is not sheared. some good news.