Snowmobile Fanatics banner

1 - 20 of 23 Posts

·
Registered
Joined
·
1,090 Posts
Discussion Starter #1
Just rebuilt the Storm, got to hear her run tonight. She started up, did good for a second, then started speeding up, at first gradually then it started racing, so I shut it off at about 5000RPM. I have no clue what is wrong with it. At first I thought an air leak, but I wasnt sure. Would really like to diagnose this, didnt wanna blow up a fresh engine. Thanks guys.
 

·
Registered
Joined
·
1,219 Posts
check to make sure throttles arent hanging up, make sure theyre adjusted properly. make sure all carbs are adjusted properly. could be an air leak, but itd have to be a major one to race like that.
is the belt and clutch on? keep the track off the ground and run it. it may come right back down.
im assuming no carb jetting was change or other mods? just a rebuild?
be ready on the kill switch.
 

·
Registered
Joined
·
1,090 Posts
Discussion Starter #3
Tore into the bottom and all, but I just cleaned the carbs, didnt mess with the jetting or anything. Clutch is on it, belt's not connected. It was really getting up there which made me concerned. We tried this a few times, and it still raced everytime. Kinda disappoints me, but its all part of the fun.
 

·
Registered
Joined
·
2,916 Posts
MY XLT did that, check the throttle cables.
 

·
Registered
Joined
·
1,090 Posts
Discussion Starter #5
What about it being too lean and it trying to catch up? I didnt touch the carbs besides to clean them, but I did bore it out .020 over.
 

·
Registered
Joined
·
523 Posts
check your throttle cables!!! your throttle shouldn't be too tight needs some play. now if you want to check for an air leak. you can do one of the following:
get it running and spray around the engine with starting fluid and if the engine revs up u have an air leak, but in this case you can't do that.
the other thing is to do this: PRESSURIZE THE ENGINE WITH AIR!!!!!!!! and then listen for leaks if you don't hear any let it sit for a couple hours and see if the gauge moves if does refill to the same amount of air and then let it sit overnite. check it in the morning. if u loose 2 lbs or less you are good but anymore than that u better repressurize if needed and get some soap an water spray mixed up an start spraying.

goodluck
 

·
Registered
Joined
·
1,219 Posts
pretty much every post has advised, CHECK THE THROTTLE CABLES, let us know what you find. make sure theyre all opening and closing evenly and start from the same position! did you move the idle air screw at all? make sure its adjusted properly all 3 the same.
as fpr it being to lean, i highly doubt it. not for it racing from the get go.
as for the air test, this to me is old school and a pain in the rear! specially on a 3 cylinder. to do this properly you have to have each cylinder so that the piston is below the transfer port, other wise youre only testing the rings. also have to have block off plates for the exhaust and intake. basically have to do each cylinder 1 at a time.
a real pain and takes awhile also have to have right tools to do it. (leakdown test)
 

·
Registered
Joined
·
523 Posts
yes the air test is old school but very very effective!!! doesn't take long to do. and you can do all 3 cylenders at once. and as for the right tool you can make one from compenents from your local hardware or farm store.

goodluck
 

·
Registered
Joined
·
1,219 Posts
if you know a way to test all 3 cylinders at once, clue me in. youre gonna have 1 cylinder thats above the transfer ports and(if your ring/cylinder clearance is good) your not actually getting the air past that and not effectively testing bottom end. this test it to check bottom end not top end.
 

·
Registered
Joined
·
1,090 Posts
Discussion Starter #10
Will check the cables, did have those off, maybe I didnt do something just right. Thanks guys!
 

·
Registered
Joined
·
2,016 Posts
polarisrxlrider said:
Will check the cables, did have those off, maybe I didnt do something just right. Thanks guys!

Of course you just clean the carb, but if you didn't put tha carb back where they supossed to go they can be a little out of sync. Did that before, you always wanna check and adjust carb sync before starting a rebuilt engine. Idle screw adjustment?
 

·
Registered
Joined
·
9,982 Posts
If you put the carbs in the wrong locations after cleaning them the jets could be wrong...

Look for a sticker under the hood and make sure your jetting is right. (as well as all the stuff mentioned above)
 

·
Registered
Joined
·
1,090 Posts
Discussion Starter #13
I bet that's what I did. Thought all the jets were the same? So my easiest fix may be just to switch the carbs around?
 

·
Registered
Joined
·
2,016 Posts
polarisrxlrider said:
I bet that's what I did. Thought all the jets were the same? So my easiest fix may be just to switch the carbs around?
no, on that engine the jets are not the same, Like you said switch the carb, but I'm still confused... the rpm should not go up just by switching the carb!!!
 

·
Registered
Joined
·
9,982 Posts
Do you know which is which? If not, on the bottom of each carb, the jet is just inside the hex cap and easily readable by just removing the cap. Of course, now I think about it, jet size shouldn't matter till half throttle or better so it probably isn't your problem.

On the sticker under the hood should also be basic carb settings, IE: mixture screw settings, etc. Make sure you set the carbs to those.
 

·
Registered
Joined
·
1,090 Posts
Discussion Starter #16
Will do. I was happy to hear her run, but about crapped myself when she took off!
 

·
Registered
Joined
·
1,090 Posts
Discussion Starter #18
STEVE650 said:
polarisrxlrider said:
I bet that's what I did. Thought all the jets were the same? So my easiest fix may be just to switch the carbs around?
no, on that engine the jets are not the same, Like you said switch the carb, but I'm still confused... the rpm should not go up just by switching the carb!!!
Yeah, I'm gonna look at those cables either tonite or tomorrow. Thanks guys.
 

·
Registered
Joined
·
1,090 Posts
Discussion Starter #19
So what exactly am I looking for? just where it connects into the carbs? Or am I looking at the junction box to make sure they are all opening correctly, or do I have to tear back into the carbs? Thanks guys, really appreciate the help!
 

·
Registered
Joined
·
1,219 Posts
check to make sure proper play at the thumb throttle, check to make sure proper play where each cable cscrews into the cap on the carb. take airbox apart and make sure one or more, slides aint stuck up. 2 at a time make sure the slides open evenly.
 
1 - 20 of 23 Posts
Top