having an issue with the sled not wanting to rev past 3k-3500. its an 89 EX570, i ran it with the belt off and same thing ( i know i shouldnt run it with the belt off but I had to see what it was doing) it idles just fine, i just cannot get it to rev up and it starts bogging, i've read all the other bogging threads and couldnt find anything with my set up. i've gone through the entire machine and this is what I've got.

145-150 psi on both cyls,
all new fuel lines, fuel pump, fuel filter, fuel tank has been cleaned.
PSI single pipe,
SX style y-pipe with the 20mm removed.
38mm flatslides from a 94 Vmax 600.
Comet 108c clutch.

the problem is within the carbs or possibly the clutch. the sled sat for 3 or so years before I restored it and i don't know if the clutch could be seized up or not, but you'd think it would still be able to rev with the belt off correct? I'm pretty sure the TORS is functioning. i disconnected the throttle switch to check it and it would kill everytime i hit the gas. to me that tells me that the carb switch is operating correctly. I've got 160 mains, is this way too much fuel? 50 pilots and i'm not sure what the clip position is on the needles. stock mains for the vmax 600 is 156.2, stock mains for a exciter SX with flatslides is 155. i jetted up because of the pipe but could I have gone too far up? would the mains even affect anything besides WOT? i need all the input I can get on this, going up north in a few weeks and i'd like to have time to play in the snow before i take it on a trip. I may ditch the old 108c and go for a different setup, i'm sure its long worn out by now. any recommendations for a good primary on this thing? THANK YOU

Hey there

New guy to the forum... Actually just got back from a 100 mile ride. Quick intro, started riding sleds when i was 3 or 4, rode til i was 10 or 12 then I got into the dirt sports alot more...Still a big air dirt junky but just recently got back into sleds... been wheeling and dealing a little and ended up getting a 87 exciter...Great sled so far...Other then the suspension. Maybe with a little work it can be improved some.

Anyway... just got the thing last night. Rode it around my yard and it went like a bastard, lifting skis, etc. Took it out tonight for a real ride (probably put 100 miles on the old girl!) and she was just loading up....Now I am having a very similar problem to yours...only I can't get past 6k. Tommorow after work I'm gonna try the cursory plugs and carbs cleaned/resynched. My sled is on a fresh rebuild...It was pretty low on fuel and i ran it out...Im guessing clean the carbs and some new plugs and mine will be mint.

If I find anything else tommorow, I will let you know. Most likely something stupid.

I threw some plugs in mine tonight and put some more good miles on....gotta love that old exciter....Hell I was in front of the big boys or running right with em most of the night...great ride.

After reading your post again...I would say just take it from the top. You got good compression: check. Spark nice and strong....stupid question, but, good plugs?? Next go through your fuel system...Check your needle clip position, make sure everything is clean, synched, etc. Any airleaks anywhere...bad intake boot maybe?


good luck with it...hope you get it runnin soon im havin a blast on my 500$ oldy and running with the guys that got big money tied up into it.