Hello everyone. Hope we got some good tech people here cause i got something strange going on with my 1991 yamaha exciter 570. It has not worked right since i got it last winter. Here is my main problem now. I just redone the top end with all wiseco parts (gaskets, pistons, rigs, etc)

PROBLEM: On idle the machine only runs on one cylinder, as you press the gas you can here the machine pick up the other cylinder (at about 2500RPM). when you let off the gas and the machine idles down it looses the cylinder. You can hall the spark plug cap off one side and it stays going, off the other side and it cuts out. Ignition problem? Carb problem? Engine problem? i dunno?????

I have no idea so if anyone has any idea can you please help me.....Please!

I've tried, New top end, New coil, new crank seals, new clutch(ha ha)
one mechanic around here still seems to think it is my crack seal....

THANKS FOR TAKING THE TIME TO READ ALL OF THIS AND ANY COMMENT WOULD BE GREATLY APPRECIATED...

Sorry I can't help you out on this one, but welcome to the best snowmobile site on the web!!

Enjoy your stay.

I'm sure someone will come through with an answer for ya.

Thanks, im sure someone will have some idea's.

not to sure but might be a fuel dilivery problem?, cleaned the carbs and checked the fuel pump? could it be a bad ground?

Welcome to the site.

I have a 1993 Yamaha Exciter II 570. It is very tempormental and I never know when it will pick up and go. I cheked with many macanics and none of them could fix it either, except for a long bill.

In short, I am in the same boat as you, Briann 30. Here is what i did to fix it: I bought a newer sled (2001 Ski-Doo MXZ 700) and gave the exciter to my brother to ride.

Hope this gives an idea or two.

I assume it's always the same cylinder that your loosing? Have you confirmed you have spark at the low idle? If so, do a plug check after running at low rpm. Is it getting enough fuel...too much? I'm not sure what the carb is on this sled but maybe your low speed fuel delivery is NFG - plugged needle / pilot - or set too high. Your main jet will not provide enough fuel until you pick up the RPMS..maybe this is what's happening.

The low speed is adjustable for each of my carbs on my Phazer...maybe your low speed needs adjustment?

my two bits...good luck!

Originally posted by Psxbs@Sep 2 2004, 05:17 AM
I bought a newer sled (2001 Ski-Doo MXZ 700) and gave the exciter to my brother to ride.

Hope this gives an idea or two.


I did the same with my Exciter, always bogged out. Can't figure out what's wrong with it so we're selling it. (I'm sure it could be done if someone had alot of time on their hands. I bought a '98 SRX 700.

check spark right off the bat. Could have some resistance goin on there. If not check your head studs. Had a similar problem on my phazer and 3 of the 4 head bolts were cracked off. Hope u find out the prob. 22 foot lbs should be good.

If it's ignition then try one of those test plugs and see if that cylinder's plug is sparking.

More likely is that your carb is not clean enough especially in the choke and low speed circuits. If your really mechanically inclined try swapping the 2 carbs around so you have cleft on right and right on left. Then run it and pull off a lead after it's warmed up.

When you only have 1 cylinder operational it is really hard to start. I lost a piston this past year. No compression at all. It would run. Badly and noisy. And about 6000 RPM on the trail max.

If after the carb thingy or even before try a simple compression check with a good screw in type guage. Try it cold and warm see what the difference is.

Good luck

do you have TORS carb switches on this model. my 92 did and they would #### me off you would try to take off full throttle it would spit sputter bog down. you disconnect them, cant remember if you have to put a jumper in or not and it will run good. try this and let us know

You never said you changed the plugs. Did you?

im guessing that its dual carbs. clean both of em. try that. if that doesnt work maybe you should try changing the plugs. if not do a compression test. if you dont have one pick one up at sears for about 40$. maybe your rings are shot.

swap your plug wires,,,, then start it,,, pull the plug wire that you did before and it stayed running,,,, when you pull that one, if it keeps on running, you have good spark and you have a fuel problem. if it shuts off,,, I would assume you have a problem with that wire, cap, or plug

I would guess its a plugged pilot jet,,, when you get it running, your main kicks in and delivers the fuel to the other cylander and then it runs fine,,, but when your rpms come down you main closes and you are back to your pilot,,,,

Dude i have almost the same problem with my Eciter 570 deluxe. Whwn ever i go to hit the throttle and it just boggs out really bad then kicks in then go. If you find your prob find my listing and give me a reply on what was wrong with your sled thanks.

HOPE YOU FIXE YOUR SLED

Thanks Guys for all the support. I have switched the carbs around, Left to Right And Right to Left. Now it will run when i hall off the caps. Strange, So i am still thinking it is a carb problem, i am dropping it off to yet another mechanic this week, i will post anything that i find out. Thanks.