thundercat running on 2 cylinders

[atcfreak85]

I just got this sled about a week ago, it is a 94 thundercat 900. It is only running on two cyliders and I need help figuring this out I'm not the the best mechanically with snowmobiles! I put new plugs in,cleaned carbs and new gas. I was told that the choke plungers stick on the older tripples sometimes so I cleaned it out and it does not seem to be sticking to me anyways. It also has spark. I t seems to be getting alot of gas maybe even too much seeing how the pulg is soaked after it has been started and I pull it from cylinder 1. Also I pulled all the plug wires off to change the plugs, Is there a certain order these must go back on from left to right when sitting on the seat your left hand side being cylinder #1? What thing can I look for and do to try to correct this problem myself? and which way should these plug wires go back on or doesn't it matter? Thanks :wondering

[Maico]

Do a compression check 1st.

[atcfreak85]

O.k I'll have to get a compression tester. Thanks, anyone else have any ideas?

[sandpuppi101]

I had a '95 900 T-Cat ,Fast sled !! Do your compression check 1st,then something that you should look at is the carbs ,are they in sync- that will have to be checked also!! Just so you know have that machine up in the rear and DO Not take the belt off when you are running it,that motor will over rev and you can do some serious damage to alot of mechanical's. I will follow up and try to help ya ,those sleds went 108 out of the crate ,just a little bit of trivia!!! Here's a pic of me up in Marquette ,Mi !!!

[atcfreak85]

well like I said I don't know that much so.... how do I see how the carbs are insync? Also I have had the belt off while running it! Funny that you say that I was just thinking today I should probally put the belt back on! I hope I didn't mess any thing up! :eek: What do you mean blow it up or what? I hope I didn't! Don't you need a special tool to check the carbs rite?

[MTS]

witch Cylinder isnt firein? Almost bet the middle one is Fryed...People dont generally Jet them properly and The Middle cyl runs little hotter, Leans it out-boom there go's all the nickasil.....

[Jason Hall]

Here Is a quick easy way to find out If the cylinder that Is not firing does'nt have enough compression to run. Pull out the plug on the suspected cylinder. Hold your finger over the plug hole. If you can push real hard & totally stop the compression from forcing your finger off the plug hole while cranking the engine over, then It will not run. Once the engine Is running, the other 2 cylinders would make a weak cylinder sometimes spudder Intermittently. Did you try changing the plugs & see If that helps. The best way to start with syncing the carbs Is to set the slide heights the same when the throttle Is all the way released. I use a small drill bit & stick It In the carb under the slide & adjust the Idle screw until they are all the same (with the engine off of course). After that you should have a carb syncronizer to set the air screws. Once you have the slide heights set, then make sure all 3 carbs open at the same time. You might have to adjust the cables on the carb tops to make them all open at the correct time. Then make sure they all are at wide open throttle at the same position of the throttle lever hitting the handlebar. A easy way to find out what cylinder Is not firing Is to see If that exhaust manifold or closest point of the pipe to the cylinder Is getting hot. the cold one aint workin.

[atcfreak85]

If you are sitting on the seat it is the cylinder on the left. (By the clutch). Thanks for all the help so far! Keep it coming! I'll try some of your suggestion tomorrow.

[Maico]

PTO is the 1 that will usually burn down first...mostly due to the extra heat created by the clutch. When you do your compression check...pull ALL of the plugs out,turn the key to OFF,hit the kill switch and hold the throttle wide open. Give it a good 5 or six pulls. Do this for each cylinder. Those T-Cats can be finicky but run like hell when tuned in.

[brapp]

another thign is check crank seal, the clutch side tends to be the 1st one to go out die to the torque and radial play fo the clutches.

[jason 32]

yea it prolly has a fireing order as to wich ones fire before the other one does
unless there is only one pick up,and couil with 3 wires - but that would be odd-
clean the pilot jets ,sync the carbs-new, plugscheck each wire for power even with the other 2 running it should be running /fireing with low comp the other 2 would keep it goin- check the fire/timing/plug wires