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Viper Timing Gear

murdered141

Snow Punisher
Joined
Nov 24, 2015
Messages
1,456
Age
43
Location
U.P Michigan
Country
USA
Snowmobile
Yamaha sr viper 15 ltx dx, mpi 190 turbo, straight line header, 38" mtx front end, mtx steering, mtx seat, xtx 141" skid and 2.25" power claw track
2019 sidewinder xtx le, sleeping for now
In an attempt to figure out my stalling issue on my 15 viper with mpi turbo, I received a comment on fb that if I had broken a belt really hard that it could've spun the timing gear on the stub shaft, that would somewhat explain the stalling and sometimes not starting on first attempt and rough idle on start up, is this even possible if so how would I check if the gear spun, understand the process off pulling it out but wouldn't i have bigger issues than just stalling or rough idle sometimes?
I've already checked the tors and throttle cable routing and adjustment, still need to unplug the tors at the thumb throttle to see if its possibly a bad tors switch, no code's and tors is reading 0% and 99% in all positions, this is starting to get very frustrating, and yes I looked at the other stalling threads.
Thanks in advance
 

In an attempt to figure out my stalling issue on my 15 viper with mpi turbo, I received a comment on fb that if I had broken a belt really hard that it could've spun the timing gear on the stub shaft, that would somewhat explain the stalling and sometimes not starting on first attempt and rough idle on start up, is this even possible if so how would I check if the gear spun, understand the process off pulling it out but wouldn't i have bigger issues than just stalling or rough idle sometimes?
I've already checked the tors and throttle cable routing and adjustment, still need to unplug the tors at the thumb throttle to see if its possibly a bad tors switch, no code's and tors is reading 0% and 99% in all positions, this is starting to get very frustrating, and yes I looked at the other stalling threads.
Thanks in advance
I'm not sure what causes it, but go ahead and check it. The special spline should line up with the mark.
 
The one at dealer would not do more than a fart trying to start. I would think it your tune causing starting issues. New Flash. I had to richen mine 5% at low rpm and gained over 100rpm at idle and much smoother.
 
Yes new flash and cranks longer to start, sometimes 2-3 attempts, don't want to blame the new flash cause it was stalling prior to new flash just after turbo install, the mpi gems controller has an idle setting in mode 1, mine is set to 3 which may be a tad rich, cause when i give it some throttle on start up, it fires up fine, by giving it some air it leans it out a bit
The one at dealer would not do more than a fart trying to start. I would think it your tune causing starting issues. New Flash. I had to richen mine 5% at low rpm and gained over 100rpm at idle and much smoother.
 
Yes new flash and cranks longer to start, sometimes 2-3 attempts, don't want to blame the new flash cause it was stalling prior to new flash just after turbo install, the mpi gems controller has an idle setting in mode 1, mine is set to 3 which may be a tad rich, cause when i give it some throttle on start up, it fires up fine, by giving it some air it leans it out a bit
Lean it up and see. You have a AFR guage I assume?
 
Friend has a 16 ZR 7000 having a hard time starting also hot /cold but when it starts sled runs great. Brought it to dealer started every time. Started acting up again brought it back to dealer and they found timing had skipped 2 teeth and needs new gear. Has no idea how it happened but it’s going to cost $650 plus labour.
 
Friend has a 16 ZR 7000 having a hard time starting also hot /cold but when it starts sled runs great. Brought it to dealer started every time. Started acting up again brought it back to dealer and they found timing had skipped 2 teeth and needs new gear. Has no idea how it happened but it’s going to cost $650 plus labour.
My dealer changed mine because of starting issues after new flash and it is now working great. Mine was out 1 tooth. Always ran great once started. If I gave mine a little throttle it would lean it out and fire every time
 
Are you only having to give it throttle to get it to fire on start up and then let off or are you having to use some throttle to warm it up? Does it run rough or like it's missing a cylinder or two at first on cold start?
 
Are you only having to give it throttle to get it to fire on start up and then let off or are you having to use some throttle to warm it up? Does it run rough or like it's missing a cylinder or two at first on cold start?
I would only have to give it throttle at start up. Then it would idle fine and run normal.
 
My hot start's sound like running on 1 or 2 cylinders
 
My dealer changed mine because of starting issues after new flash and it is now working great. Mine was out 1 tooth. Always ran great once started. If I gave mine a little throttle it would lean it out and fire every time

So your sled is starting and runs great now? No cold start problems?
 
My dealer changed mine because of starting issues after new flash and it is now working great. Mine was out 1 tooth. Always ran great once started. If I gave mine a little throttle it would lean it out and fire every time
So what is the cause of timing skipping a tooth or two. Will Dealer cover repair?
 
Last edited:
So what is the cause of timing skipping a tooth or two. Will Dealer cover repair?
Some have said it could be caused by a backfire? I know with the old flash I had a few good backfires at start up and after good full pulls.
 
Gonna take mine apart this evening, after pulling the primary clutch off and taking the four bolts out, it should pull out correct, anything else I should know?
 


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