12 Vector Ltx belt issue

[Apexpat]

I have a 12 Vector that has suddenly started eating belts, 3 in the last 1000 miles. I purchased the sled with 5,000 miles it had an Ultimate 805 belt on it with stock clutching. Ran it a few thousand miles and blew the first belt. Put on a new 8DN belt and lasted about 2,000 miles. One thing I had to do was remove the 3 small shim washers in the back of the secondary as it was squealing bad with the 8DN vs the Ultimate. A few weeks ago I blew the 8DN belt and replaced with 2 older belts I had from my Apex. Blew these 2 older belts in 400 miles in back to back days. These were older belts so I thought ok let’s put on a new one. Replaced this week with a new 8DN belt and blew in 400 miles. I usually get 4-5000 miles on all the apex and vectors I’ve owned and replace as general maintenance before blowing. I’m guessing I could have got more than 5000 miles on these other sleds. Looks the belts are heating up and the top edge of the belts are delaminating. I did notice the top edge of the belts were sitting below the top edge of the secondary so I put the 3 washers into the back of the secondary to see if raising the height will help. It does squeal slightly at idle with the new 8DN belt and good so far after 200 miles. Wondering if the belts were sitting below spec in the secondary as the longevity went down after removing the shim washers in the secondary. However, breaking a brand new 8DN belt in 400 miles is extreme, should get a few thousand miles minimum. The top of all the belts are coming apart in large chunks separating from the main part of the belt. The sled has 12,000 miles and I noticed like others have said the primary is definitely grooved and wondering if that is the main issue or was just sitting too low in the secondary without the shims? Other than the short belt life the sled seems to be running fine clutch wise not slipping and shifting fine with good top end. Can’t be blowing belts frequently at the price and don’t want to get stranded on a longer trip. This is definitely a new one for me, before these 3 broken belts the last 2 weeks, probably only had 2 broken belts in over 60,000 miles going back to my 2003 RX-1, all with 8DN belts.

 

[Apexpat]

Anybody out there on thoughts for suddenly blowing all these belts

 

[RobX-1]

Chasing a similar issue in my 18 Apex where I can't seem to get more than 1500-2000 miles on a belt. Started going thru belts recently where I was experiencing the top portion of the belt was delaminating too where it you didn't catch it soon enough, would start spitting out pieces of belt fuzz on your lower left leg/foot and making a mess on the backside of your side panels. I thought my issue was due to the belt sitting too high in the secondary as a new belt would squeal so removed the the thin washers on the 3 screws behind the secondary. They also had a thick washer too so left them and only removed the thin one. When I checked my 08 Apex which doesn't have this belt issue and has way more miles, it only had the one thick washer and no thin washer. My thinking was that by sitting too high in the secondary, is what caused the top portion of the belt to delaminate but time will tell. I don't have any grooves on the primary and use a scotch-brite pad to periodically clean the clutch surfaces. Something I also checked with the three clutch buttons on the secondary to ensure they were intact which they were. Even disassembled the clutches to give everything a thorough cleaning but still having the belt issue.

I will say that after removing the thinner washers, I have put over 1000mi and the belt hasn't delaminated yet so that's better than your 400mi but in my case, it is still too soon to tell if my belt issue has been resolved. Outside of sending the clutches to Thunder Clutching where they can split the primary, not sure what else to try/do. I didn't on my 08 Apex as i wasn't the original owner but on the 18 Apex, I even marked the two secondary halves from the get-go to ensure its still balanced the way it came from the factory. I just want to make sure it's not something else at play before going that route.

 

[Apexpat]

Chasing a similar issue in my 18 Apex where I can't seem to get more than 1500-2000 miles on a belt. Started going thru belts recently where I was experiencing the top portion of the belt was delaminating too where it you didn't catch it soon enough, would start spitting out pieces of belt fuzz on your lower left leg/foot and making a mess on the backside of your side panels. I thought my issue was due to the belt sitting too high in the secondary as a new belt would squeal so removed the the thin washers on the 3 screws behind the secondary. They also had a thick washer too so left them and only removed the thin one. When I checked my 08 Apex which doesn't have this belt issue and has way more miles, it only had the one thick washer and no thin washer. My thinking was that by sitting too high in the secondary, is what caused the top portion of the belt to delaminate but time will tell. I don't have any grooves on the primary and use a scotch-brite pad to periodically clean the clutch surfaces. Something I also checked with the three clutch buttons on the secondary to ensure they were intact which they were. Even disassembled the clutches to give everything a thorough cleaning but still having the belt issue.

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I will say that after removing the thinner washers, I have put over 1000mi and the belt hasn't delaminated yet so that's better than your 400mi but in my case, it is still too soon to tell if my belt issue has been resolved. Outside of sending the clutches to Thunder Clutching where they can split the primary, not sure what else to try/do. I didn't on my 08 Apex as i wasn't the original owner but on the 18 Apex, I even marked the two secondary halves from the get-go to ensure its still balanced the way it came from the factory. I just want to make sure it's not something else at play before going that route.

I feel like my issue is just the opposite of yours. Belt sitting too low in the secondary and causing the top edge to heat up and come apart. I added the shims back and it’s even with the top of the clutch or slightly above with an occasional squeal at idle. Will also check alignment and if not that I’m thinking the grove in the primary heating up the top edge of the belt. This is really frustrating as I’ve had huge belt life longevity with all my Yamaha 4 strokes.

 

[RobX-1]

My thinking was that with those thin washers, it caused the belt to be higher in the secondary, above it, and that was what was possibly causing the top of the belt to delaminate. Almost seems we have same issue with belt delamination but different culprits. I initially thought it was my exhaust clamps on the two flex pipes closest to clutches being loose once heated up (were always tight like the other two when checked but pipes were cold) and generating excessive heat in that area and causing the belt to fail (ie. spit out belt fuzz). Since then, I've now noticed that the delamination occurs first and if caught early, can prevent the fuzzy mess. Knowing it's a belt delamination issue and the new belt would always squeal at first, is what led me to the removal of the thin washers to try this time. Knowing your results, I'm not confident I'm any closer to a resolution than you are. What's odd and frustrating like you mention is that it never used to do this and am not sure what would have changed. It was right around the time I changed out my exhaust donuts that this started occurring and that was when it had around 10k so it never had a belt issue before then.

 

[RobX-1]

One thing I did see mentioned in the other post you posted in and haven't checked was the lower protection plate possibly sitting a little higher after blowing a belt for the first time and now maybe it is getting into the belt. However, I never see signs of gouging in the pieces of the delaminated belt that fall off or get peeled off the belt so not sure that is at play here.

 

[Apexpat]

My thinking was that with those thin washers, it caused the belt to be higher in the secondary, above it, and that was what was possibly causing the top of the belt to delaminate. Almost seems we have same issue with belt delamination but different culprits. I initially thought it was my exhaust clamps on the two flex pipes closest to clutches being loose once heated up (were always tight like the other two when checked but pipes were cold) and generating excessive heat in that area and causing the belt to fail (ie. spit out belt fuzz). Since then, I've now noticed that the delamination occurs first and if caught early, can prevent the fuzzy mess. Knowing it's a belt delamination issue and the new belt would always squeal at first, is what led me to the removal of the thin washers to try this time. Knowing your results, I'm not confident I'm any closer to a resolution than you are. What's odd and frustrating like you mention is that it never used to do this and am not sure what would have changed. It was right around the time I changed out my exhaust donuts that this started occurring and that was when it had around 10k so it never had a belt issue before then.

You may be onto something with the exhaust clamps causing excessive heat. The sled has 12,000 miles with the original donuts. I noticed it sounded a little louder this year and on this past trip had a slight backfire after letting off full throttle. So you’re saying exhaust gas blowing by the donuts and adding extra heat to the clutch? Like yours the top of the belt comes apart and I immediately stop when I hear it before the belt comes apart and I have a big mess.

 

[Apexpat]

One thing I did see mentioned in the other post you posted in and haven't checked was the lower protection plate possibly sitting a little higher after blowing a belt for the first time and now maybe it is getting into the belt. However, I never see signs of gouging in the pieces of the delaminated belt that fall off or get peeled off the belt so not sure that is at play here.

Yep that lower lower protection plate bent up the front lip causing the new belt to rub against it. I immediately heard it after changing the belt and had to pull off and bend straight and rerevet.

 

[maim]

check on the bottom of the belt gaurd. for some reason the one on my 11 bent down and i was getting rub marks on it.

 

[74Nitro]

Put a straight edge on the primary sheaves to see how much wear there is about half way up. Don't worry about the grooving near the bottom, it has almost no effect.
The sheave surfaces need to be straight.
I had this same problem on a rs venture years ago and it was excessive wear half way up the sheaves, eating belts like crazy.

 

[RobX-1]

Thanks guys, will check both the guard and the primary sheaves and report back.

 

[RobX-1]

So you’re saying exhaust gas blowing by the donuts and adding extra heat to the clutch? Like yours the top of the belt comes apart and I immediately stop when I hear it before the belt comes apart and I have a big mess.

Yes, that was my thinking. Although I did order new clamps, I ended just grinding down the stops so as to be able to tighten the clamps more. I even went as far as to leave the seat off before re-assembly so I could start engine and get exhaust up to temp to ensure the clamps stayed tight. Unfortunately, even after doing this, I am still having the tops of the belts delaminating.

 

[Apexpat]

Put a straight edge on the primary sheaves to see how much wear there is about half way up. Don't worry about the grooving near the bottom, it has almost no effect.
The sheave surfaces need to be straight.
I had this same problem on a rs venture years ago and it was excessive wear half way up the sheaves, eating belts like crazy.

There is a definite groove in the center of the primary. So if I get another primary clutch what is the answer so it doesn’t happen again? Not run the 8DN belt something softer?

 

[74Nitro]

There is a definite groove in the center of the primary. So if I get another primary clutch what is the answer so it doesn’t happen again? Not run the 8DN belt something softer?

Correct.
I realize everyone is a big fan of the 8dn belt, I used to be also.
However, I came to realize I was wrong. The 8dn is too hard.
Find a clutch with straight sheaves or order new ones. Use the ultimax belt.
I have almost 19000kms on my sidewinder using this belt and my sheaves are straight as new.

 

[Apexpat]

Correct.
I realize everyone is a big fan of the 8dn belt, I used to be also.
However, I came to realize I was wrong. The 8dn is too hard.
Find a clutch with straight sheaves or order new ones. Use the ultimax belt.
I have almost 19000kms on my sidewinder using this belt and my sheaves are straight as new.

Strange that this is finally rearing its ugly head after all these years. I’ve run the 8DN since 2003 in all my Yamahas with great longevity.