Yamaha "8DN" VS. Dayco Ultimax 3

[SledFreak]

Will a Ulmer stage 3 kit eat this belt alive or what??

Please stick with the 8DN belt. If you do want to switch to a Ultimax belt use the new XS model of belts, but you will have to make adjustments to the clutch setup.

If your primary clutch is not adjustable, you will have to shim the spider for proper side clearance, which entails breaking it down with a grunt tool to re-shim it.

Hammer, I want to see you shim the spider on a Yamaha! You'd have to change the split collars on the fixed sheave to tighten up the belt clearance on a Yamaha.

What do they use the 8dn00 for?

The 8DN-00 belt was used on the Yamaha SRX starting in 1998 and all 4-stroke models. Yamaha has come out with a new belt with the same part number, just has -20 on the end of it instead of -00. This new belt has the edges cleaned up slightly and the top side of the belt measures a little wider than the old 8DN belt.

Allen, is it new for this year?

 

[RacerDave]

Hey Hammer, wait a minute. I just noticed that both of the pics you posted neither has a oem clutch. One is a P-85 on a triple, and it looks like the other on the 4 stroke is also with a replacement cover.

 

[**sj**]

the other cover is a high tech 911 with belt adjuster

 

[HAMMER]

Hammer, in all the time I have been reading your post's, I believe thats the first GOTCHA' I can remember LOL!!!

Ya, it happens once in a while, when you get too many things going at once. I had just been talking with someone about setting up for the Starting Line Products MTX weights for the P85, how they have a thicker belly, causing them to make contact with the spider in some cases, and how he may have to shim the spider to get the proper clearances.

Is it new for this year?

Nope, they've been out for over a year now, here's what Allen said last year about the XS.

We're testing the new Ultimax XS belts. So far they have showed a gain over the 8DN on the grass. Will try them out on the snow as well.

The other cover is a high tech 911 with belt adjuster

Yep...http://www.hitechperformance.com/911response.asp
Old P85/P90 thread...http://www.ty4stroke.com/viewtopic.php?t=17564

 

[SledFreak]

I just got off the phone with my dealer and -20 is not a -20, it is a -01 and it is a wider belt and it's now 5.00 dollars more than the -00. He said they just started getting them last February. I will be getting a -01 belt for my sled this yeat, even though my clutches are machined for the OD.

 

[Srxspec]

Will a Ulmer stage 3 kit eat this belt alive or what??

Please stick with the 8DN belt. If you do want to switch to a Ultimax belt use the new XS model of belts, but you will have to make adjustments to the clutch setup.

If your primary clutch is not adjustable, you will have to shim the spider for proper side clearance, which entails breaking it down with a grunt tool to re-shim it.

Hammer, I want to see you shim the spider on a Yamaha! You'd have to change the split collars on the fixed sheave to tighten up the belt clearance on a Yamaha.

What do they use the 8dn00 for?

The 8DN-00 belt was used on the Yamaha SRX starting in 1998 and all 4-stroke models. Yamaha has come out with a new belt with the same part number, just has -20 on the end of it instead of -00. This new belt has the edges cleaned up slightly and the top side of the belt measures a little wider than the old 8DN belt.

Allen, is it new for this year?

I just got off the phone with my dealer and -20 is not a -20, it is a -01 and it is a wider belt and it's now 5.00 dollars more than the -00. He said they just started getting them last February. I will be getting a -01 belt for my sled this yeat, even though my clutches are machined for the OD.

You're correct SledFreak (oops!) the new belt has a -01 for it. Here is the belt measurements I'd posted over in the FX Nytro forums.

Brand new belts measure as follows.

8DN-17641-00
Top width: 1.358"

8DN-17641-01
Top width: 1.383"

 

[Srxspec]

Hammer, in all the time I have been reading your post's, I believe thats the first GOTCHA' I can remember LOL!!!

Ya, it happens once in a while, when you get too many things going at once. I had just been talking with someone about setting up for the Starting Line Products MTX weights for the P85, how they have a thicker belly, causing them to make contact with the spider in some cases, and how he may have to shim the spider to get the proper clearances.

That's what happens when you stick different brand clutches on a Yamaha, your eggs get scrambled! LOL!

 

[SRXSex]

Brand new belts measure as follows.

8DN-17641-00
Top width: 1.358"

8DN-17641-01
Top width: 1.383"

So I assume the new -01 belt can be slapped on without any clutch adjustmets. ????

What would be the bennifit, more top end??

 

[Srxspec]

The new 8DN belt can be used without any problems. There likely won't be any difference in performance. It will be slightly smoother at engagement for sure.

 

[rightarm]

Altough the stock Yamaha is very capable,and I have been using this belt ever since I bought my 03.I tryed the Ultimax belt last year and the performance difference is night and day,so what if it dosen't last forever new belt each year better safe than sorry.Clutches run cooler as well.

 

[bjowett]

If you want to get home, the OEM Mitsuboshi belt is the best out there. Even Polaris superceded to them for their belt breakers... and their snowcross racers. It would be interesting if we could source a softer compound Mitsuboshi belt.... there allot more that makes em' better than durometer.

 

[Daranello]

Altough the stock Yamaha is very capable,and I have been using this belt ever since I bought my 03.I tryed the Ultimax belt last year and the performance difference is night and day,so what if it dosen't last forever new belt each year better safe than sorry.Clutches run cooler as well.

Whats allot better?

 

[**sj**]

they have very tight tolerances and quality control...maybe something in the man process and materials too..

 

[rightarm]

Although some might disagree,I found that the Ultimax belt gripped alot better and more consistent in the sheaves than the 8DN.Stayed cooler than the 8DN and gave off less belt dust.My 03 RX1 is more or less stock just some jetting,Ultimax belt and air box mods ,At my farm I have a 4 km race track where my buds come up and we thrash,a buddy brought his 07 Apex with about 800 km on the motor my has 4300 km we rode back to one of the two half mile straight aways and went at it.Out of the hole I got a sled length on him carried that to about 800 ft then he gained that back in the mid,after that I just rolled right by him to the end of the run.He could not believe it I told him he needed more time on the motor but he didn't fair any better on the road course part of the track either.Just my .02 but the difference between the belts was quite dramatic,8DN belt some ski lift at the line,Ultimax belt at the line provided the right amount of ski lift and transfer enough to hole shot a new F1000 and hold him off for about 800 ft until he just rolled by me on top.Overall a definite improvement on this sled for $100.

 

[iasledder]

never run this belt with an overdrive clutch setup and/or 2 speeds....

I guess everyone has their own unique problems. I have been running the XS 805 and XS 811 on my Apex ER with no problems and have both clutches cut for overdrive. I run a lot of top end as well. As Ulmer has said, with the XS belts clutch adjustments are required. In my case the XS belts pull the WOT r's down (less slippage?).