Blowing belts

[musselmark]

I have a 2010 Vector GT and have been blowing belts pretty frequently, I had it to the dealer and they did all adjustments (it needed some shims on secondary) and things got better but I still blow a couple/year. I drive it very hard (full throttle or idle, hard braking), it has 14000Km on it now and the only maintenance I have ever done is replaced buttons and thorough cleaning once. The belts always seem to go at full throttle 70-80+mph accelerating. Does the primary ever need to be broken down for cleaning etc..Does driving very hard simply = blowing belts. All belts were 8dn yamaha

 

[Ratpack]

Yes it does need cleaned. It also may need to be rebuilt. There are two bronze bushings that wear out. The clutch will close crooked and tear up belts if they are worn. There are also plastic slides that you spider rides in that wear.

 

[sgauthier]

definitely something binding to be blowing belts especially an 8DN belt . as Ratpack mentioned clutch bushings and or weight/roller bushings are shot or need cleaning. same goes for the secondary. are you sure the Centre to Cemtre and offset is correct? i would suggest you clean those at least once or twice a year depending on how many miles you do. i usually clean them at the start of the season, never had a problem.

 

[Ratpack]

If your wife isn't home, the dishwasher works really good.

 

[Mills]

You may have a broken motor mount that is allowing the motor to move/twist under high load which would cause enough clutch misalignment to blow belts as you are describing.

 

[kinger]

^^X2 check your mounts. Something is out of alignment to cause that much heat to blow the belt. You should run that vector like you stole it and have no issue with belts.

 

[musselmark]

Last year the dealer did check the mounts and said all were good. I would like to do it again, do you just pry up on the engine with a bar and look for any movement? I noticed also when I grab the secondary there is a tiny bit of rocking of movement. I know in-out is normal but this is a rocking motion as in 9 oclock in 3 oclock out and vise versa. What are the common parts that should be changed with 14000km on it.

 

[Mills]

you may have some jack shaft bearing issues if you can rock back and forth 9-3 o'clock. That would definitely cause some misalignment that could over heat and blow a belts.

 

[musselmark]

you may have some jack shaft bearing issues if you can rock back and forth 9-3 o'clock. That would definitely cause some misalignment that could over heat and blow a belts.

The rocking I was describing is from the tiny bit of play between the splined jackshaft and secondary, I guess this is normal

I disassembled both clutches tonight and cleaned them very well. They were very dirty with a lot of fibers everywhere as well, sheaves almost had a slippery shiny surface, I used a scotchbrite to clean them. How much play should there be if you slide the 2 halves of the secondary together without the spring, mine has quite a bit, is the bushing where these 2 halves slide together a wear item that should be replaced periodically? They are called BiMetal Formed Bushings on the parts diagrams.

 

[journeyman]

The rocking I was describing is from the tiny bit of play between the splined jackshaft and secondary, I guess this is normal

I disassembled both clutches tonight and cleaned them very well. They were very dirty with a lot of fibers everywhere as well, sheaves almost had a slippery shiny surface, I used a scotchbrite to clean them. How much play should there be if you slide the 2 halves of the secondary together without the spring, mine has quite a bit, is the bushing where these 2 halves slide together a wear item that should be replaced periodically? They are called BiMetal Formed Bushings on the parts diagrams.

I'd replace them. Check your primary cover bushing too. They have to be pressed in with an arbor press. I'm fortunate that I have a machine shop at my work and one of my machinist is a Yamaha rider too. How are the buttons that the helix slides against?

 

[musselmark]

I'd replace them. Check your primary cover bushing too. They have to be pressed in with an arbor press. I'm fortunate that I have a machine shop at my work and one of my machinist is a Yamaha rider too. How are the buttons that the helix slides against?

I replaced the helix buttons last year, there is still lots of material but there are tiny cracks in them down at the bottoms of their ramps. I measured the bushing/shaft and there is approx 0.010" or 0.03mm in the difference. Is there a tolerance listed somewhere? I would hate to buy these bushing and press them in only to find the same play as my originals.

 

[journeyman]

I am not sure how the Vector is for clutch wear but the 2 stroke Viper I used to have I replaced the bushings mentioned, the bushing on the helix and the buttons when it had around 7,000 miles. I never did have belt blowing issues but it helped get the performance back to normal. My current Attak has 13,000+ miles and it needed little clutch maintenance when I bought it with 12,000 miles but the previous owner rode it like a grandpa. In your case something is wrong if it keeps popping belts.

 

[musselmark]

I downloaded the service manual and there is no mention of tolerances for these bushings, just says to inspect for uneven wear/out of roundness so it can't be too important. Hopefully this thorough cleaning will do the trick

 

[4strokeluvr111]

I downloaded the service manual and there is no mention of tolerances for these bushings, just says to inspect for uneven wear/out of roundness so it can't be too important. Hopefully this thorough cleaning will do the trick

With respect I doubt that a thorough cleaning will make your problem go away. With over 8,400 miles on them and this being the FIRST time you've ever really cleaned them, I would spend the money and have both clutches totally rebuilt.

 

[musselmark]

Well, I did a thorough cleaning, replaced sliders in secondary, both bushing in secondary (new ones are really no tighter than old ones), everything in primary is good. Had dealer check alignment, defection motor mounts all good. Put new belt on, and got 10km and a bunch of threads came out of outboard side of belt, clutches too hot to put hand on for more than 3-4 seconds, belt very hot. there is a vibration coming from the front end, worse the faster I go. The jackshaft bearing feels rough/squeaks when rolled back and forth with belt off. Took secondary off and when I push and pull on shaft there is a tiny bit of play between inner and outer races of jackshaft bearing but no up/down play, pulled out seal and grease is brown. Could this tiny bit play cause some sort of vibration at high speed, which is causing the belt to slip and heat up then delaminate. While accelerating it feels to be slipping. I am going to change the bearing regardless but am just wondering if this theory sounds plausible. How often should the chaincase bearings be changed, 14000km on the sled, case oil changed yearly since new.