Over Revving After Belt Change

[JKohut]

Hey all, I'm new to the site and Yamaha ownership.

I bought a 1998 Vmax xtcp 700 earlier this winter and so far have been having a blast with it.

I went to head out for a ride this morning and after checking on the belt I found that it had seen better days so I decided to change it. After changing the belt (new belt is a 8dn-17641-01) the sled is now revving up to 8000rpm just to go 60km/h. 0-4500ish rpm feels about normal then after that it just revs higher without picking up speed.

I checked belt deflection and attached a picture of what I saw. It looks maybe a little low but nothing too dramatic. I'm new to working on sleds so I combed through the forum and found someone with a similar issue but no documented solution so just wanted to throw it out there for ideas and assistance.

Everything worked fine prior to changing the belt, the previous belt did not have any markings left but is the same width & length as the new one. As far as I know, everything is stock.

Thanks in advance!

 

[MURDER YAMAHA]

Was the old belt a 8CH belt?

 

[JKohut]

Was the old belt a 8CH belt?

I'm not sure there was no markings left on it, it's the same width and length as the new one. I don't know enough about these belts to say for sure without markings

Edit: I just cleaned it up the old one is also a 8DN same as the new one

 

[Maim]

might have been an old 8dn-17641-00 witch was slightly wider than the -01. might need to remove some tip weight to get the proper 8500 rpm that yamaha tripples like to be at.

 

[JKohut]

might have been an old 8dn-17641-00 witch was slightly wider than the -01. might need to remove some tip weight to get the proper 8500 rpm that yamaha tripples like to be at.

Looked into it the old one is in fact a -00. Should my next step be removing tip weight?

 

[Maim]

what is the peak rpm that the pipes you have want?

 

[JKohut]

what is the peak rpm that the pipes you have want?

Everything is stock so around 8500. I'm wondering if I could just add some shims to the adjustment bolts on the back of the secondary

 

[Maim]

if the belt is not squealing, i would not play with the bolts and shims on the secondary.

try pulling the rivits out of the tip of the weights and see what it tacs to while riding.

 

[JKohut]

if the belt is not squealing, i would not play with the bolts and shims on the secondary.

try pulling the rivits out of the tip of the weights and see what it tacs to while riding.

Will do, I'll give it a go. Thanks for your help

 

[JKohut]

Just an update, I tried pulling the rivet from the tip of the weights like Maim said and it made the sled rev out at a slower speed.

I found an old thread that said Yamaha put out a technical bulletin recommending the following:

Primary clutch

Outside rivet 10.3(2.4 grams) stock - new 13.9(3.6 grams)

Inside rivet 13.3(3.1 grams) stock - new 13.9(3.6 grams)

Rollers 15mm stock - new 14.5mm

Secondary clutch

stock .5mm shim - add one shim behind adj screws for 1mm total

So I copied that set up and it made it run a lot better but I'm still maxing out at around 40mph at 8500rpm.

If anyone has more suggestions I'm open to anything.

 

[Maim]

was everything moving freely when you where installing the parts in the clutch?

secondary moving freely as well?

 

[JKohut]

was everything moving freely when you where installing the parts in the clutch?

secondary moving freely as well?

Yeah I cleaned everything up nice and both clutches are moving freely

 

[Maim]

based on an issue i have had in the past and is occuring again on that sled, try a new primary spring in the clutch. they get weak over time and start acting funny. they are like $20.00 for new oe one.

 

[JKohut]

based on an issue i have had in the past and is occuring again on that sled, try a new primary spring in the clutch. they get weak over time and start acting funny. they are like $20.00 for new oe one.

Sounds good, I'm moving next week so might be a bit before I get that in but winter is still going strong here in Saskatchewan so lots of time to get it fixed this season