Loss of power last few rides - 07 Rev

[Jaynelson]

Nearing the end of the season, I had a couple rides with a crappy running sled due to a failed throttle position sensor. After that was replaced, I only got a couple more rides on it.

It seemed to run good, idle fine, etc, BUT it just didn't have much jam. Couldn't get any RPM out of it and was just overall slow as balls. After that I just stuffed in it the garage and forgot about it.

I know the 07's are notorious for wearing out clutch bushings/other clutch parts, is the big drop in performance most likely from that? I would be around 600 miles on said bushings.

 

[farmboy84]

if the bushings were wearing out you would most likely notice changes in rpm. if it was at a lower rpm consistantly i would think it would be something else.

 

[Jaynelson]

Nope, not the RPM wander that plagues 07's.....it ran very well before the TPS issue, and the clutching was quite good. But since then just no power.

I wish I could be more specific, but it's really just a general lack of power, never getting up over low 7000's for rpm....feels like a 500 fan lol. Stock jetting, stock pipe....nothing changed. I'm kinda stumped.....what would the symptoms of a broken primary be?

 

[pinnedunderdoo#3]

take your clutch apart that will tell you right away what is wrong... i know when your rollers are shot they really run like sh!t....

 

[winter brew]

Very possibly the primary bushings, rollers and secondary bushing.....if clutching related.

 

[x-guy]

does the RPM change if you change your clickers? A friend of mine had the same problem, RPM would only hit 8000, then drop down to about 7600 and hold, if he clicked up or down it made no difference, and it just felt like it had no power, just nothing. It ended up being problems in the primary and secondary (worn out parts) but as well a loose connection to the rave valve, which from what I heard was also a notorious problem.

 

[duffman]

As said above, replace the rollers. My sled did the same thing. I visually inspected the old rollers, they looked brand new but were still shot.

 

[Tuesday]

exhaust valves?

 

[khaddon2110]

does the RPM change if you change your clickers? A friend of mine had the same problem, RPM would only hit 8000, then drop down to about 7600 and hold, if he clicked up or down it made no difference, and it just felt like it had no power, just nothing. It ended up being problems in the primary and secondary (worn out parts) but as well a loose connection to the rave valve, which from what I heard was also a notorious problem.

welcome to my last year midseason......

smartest thing I ever did was go to a dealer that knows what a snowmobile is and has a clue about setups.....At no charge to me, island park adventures spot on dialed a machine that rexburg motorsports couldn't see a problem with....and because IPA did such a good job with it, i snochecked from them.

Rexburg motorsports service department is like walking into an opportunity workshop

 

[pinnedunderdoo#3]

ill gaurantee you that the exhaust valves are fine they arent hard to take off and take a look but my sled has 4000 miles i think and they pretty well looked like brand new still... and every other set i have seen has looked fine on doo motors. cat on the other hand is a different story....

 

[Jaynelson]

Rave valves should be ok....hoses are zip tied on as per the bulletin. They may have gotten a little fouled up with the bad TPS sensor, sounds like the clutch is the more likely culprit tho

 

[winter brew]

Do a compression test just for fun.

 

[enis750]

UR SLED'S pretty new, so this shouldn't be the issue, BUT..check ur carb boots???
maybe u have a tear in one of them
the mag side one is kinda hard to get at, but u never know

which belt are u running?
my bro in law had issues w the new belt's being too narrow, right from the get go
he lost a few RPM's b/c of it

that's all i can think of for now...

 

[go high fast]

my first thought would also be to check compression.

 

[pinnedunderdoo#3]

i ran a zx belt for a good part of last year and gave me more rpm also ran the 600 rev belts on it to if i remember right i lost rpm though....

 

[ucandooit]

Are you on your original engine??? The 07's had crank bearing issues where the crankcase tolerances were machined too tight causing a crank bearing failure!

 

[triple7]

If it wont turn over low 7's I would be suspicious of a crank pilling up. Possibly the clutch could be having issues but you should have seen a decline in performance rather than the sharp drop. Cranks fail quickly.

 

[bonebreaker zack]

had same problem this year , twice first was vac leak in valve hose put two zip ties on problem solved second time was the carb boot.they are famous for cracking where the eye cant see.and my buddy had a different prob but same effect, had a hole in his exhaust pipe ( under pipe )

 

[Jaynelson]

Has an 08 motor with about 600 miles on it....hopefully not crank. We'll see where I wind up....was just bored and wanted a few opinions, thanks guys