Trying The 8DN BELT

[NOS-PRO]

Gotcha Stingray719

Same belt number you posted before?

 

[stingray719]

Gotcha Stingray719

Same belt number you posted before?

Bought this one off Ebay for 39 bucks, 138-4432U4 YAMAHA BELT by ULTIMAX. Seems very burn resistant (don't ask)

 

[FAMILYMAN]

Even with clutch kit, mine is all over the board in rpm's. Just sold off all my 8dn's. Anyone have one sitting around for me to test let me know.

Thanks, Brent.

 

[YamahaTim]

Even with clutch kit, mine is all over the board in rpm's. Just sold off all my 8dn's. Anyone have one sitting around for me to test let me know.

Thanks, Brent.

That sucks! I have a few sitting around. Doesn't your dealer have any or is that a ways away?

 

[tator]

trying the 8dn because had slippage issues with the 8jp. but in turn lowered the rpm on the motor. have the clutch kit from hauck #5 which is adjustable. must have easy changable weights? secondary seems the easiest to change only 3 nuts to take off and change the spring setting. it is at 3-3 is there any reason why i cant change it to 2inside and 3 outside to raise my rpm across the board? or what will that do? clutching is new to me and i like to know how every change i make will affect the sled.

 

[cannondale27]

The preferred method is to change your top rpm at the primary. Changing the wind will affect backshift.Is odd how those of us with clutch kits have lost rpm with belt change but those without and stock clutching have not lost rpm and some like one who was overrevving actually gained some rpm?

 

[tator]

how will it change it? because when i cruse about 50 and then pin it. it only goes to 8600. reducing the secondary percent should help to correct that to higher rpm right?

 

[DeerHuntr]

Reducing it will pull the rpm farther down

 

[bleedyamaha]

140 miles

Put 8dn belt and shims on my ltxse we rode 140 miles today in 25 degree weather. With new belt I never seen over 9000 rpms and had no problem hitting 95 all day. Pulling skis up all day seems really easy. Still hit rev limiter but not as bad. Rpms really stayed around 8600 to 8800 most of day. I havent checked ink marks to see where belt was riding but this sled pulls hard. Very happy with new belt. Probably done riden this year high 40s all week.

 

[FAMILYMAN]

Even with clutch kit, mine is all over the board in rpm's. Just sold off all my 8dn's. Anyone have one sitting around for me to test let me know.

Thanks, Brent.

That sucks! I have a few sitting around. Doesn't your dealer have any or is that a ways away?

I am sure they do. Just want to test before driving an hour. If it works out I will get two new ones. I am going to try testing today, buddy has a nytro.

I did notice my stock belt is probably little over 3/16 below the top of secondary. Maybe closer to 1/4. I also agree it's softer, I tore up a belt very quickly unloading. Explains why it's all over the board in rpms. Belts compressing, I am sure of it.
------------------


Update, maxdlx and I went out this morning and did some testing. My passes were dead stop pulls, cruising to wot, shutting it down at 90 mph.

Ulmer clutch kit testing results.

Stock belt, slipping, on/off throttle inconsistent rpms, hard time getting more then 8400, but couple take offs track would spin and it hit 9k then hook up, right down to 8300-8400, hot clutch.

8nd, one washer (stock) on/off throttle smoothed out seeing 8400-8600 warm clutch

8nd, two washers on/off throttle very smooth, feels like a yamaha, seeing 8600-8800 cool clutch, pulls out of the hole hard and holds rpms very smoothly.

Maxdlx has a few pounds on me, so his rpm findings were within 100 from mine.

Also, adjustability, yes! Still room for one maybe two more washers before bottom out (bolt out). Looked like 1-1/2 washer worth IMO.

My 8nd belt is lower then the first picture, but above secondary 1/8 inch.


This was a great finding! Glad I tried it!

 

[0llll0]

So after burning my hand on my clutch with the stock belt I figured I would give the 8dn a try, it definitely dropped my rpm and my clutches are now luke warm.i no longer have any burnt belt smell at any speed so would say this is another success story for me anyways. Im running a d&d oval barker exhaust and a ullmer clutch kit, all components seem to be working together flawlessly, not hitting the rev limiter and the rpm seems to stay steady around 8900-9000. Iv seen 96mph tops so far but I am 300plus pounds so I think thats pretty good, I do miss the speed I used to get on my apex when out on the lake but that does not happen very much anymore. Over all im super happy with the viper and it looks like I will be snow checking a 2015 for the wife as her phazer is not good enough for her anymore after she rode the viper.

 

[FAMILYMAN]

So after burning my hand on my clutch with the stock belt I figured I would give the 8dn a try, it definitely dropped my rpm and my clutches are now luke warm.i no longer have any burnt belt smell at any speed so would say this is another success story for me anyways. Im running a d&d oval barker exhaust and a ullmer clutch kit, all components seem to be working together flawlessly, not hitting the rev limiter and the rpm seems to stay steady around 8900-9000. Iv seen 96mph tops so far but I am 300plus pounds so I think thats pretty good, I do miss the speed I used to get on my apex when out on the lake but that does not happen very much anymore. Over all im super happy with the viper and it looks like I will be snow checking a 2015 for the wife as her phazer is not good enough for her anymore after she rode the viper.

Great, welcome..btw take a few minutes to update your location. My son loves the viper too, but his phaser will have to be good enough for a couple years.

 

[bleedyamaha]

ink marks

Here are my ink matks on both clutches after I put 8dn belt and shims. Primary 1/4 inch from top secondaty almost gone. Very happy with these marks. You can see where the stock belt and gates belt were riding on primary. Than 8dn belt with shims.

 

[maxdlx]

By hot clutch he means burnt my thumb. By cool he means hardly no heat at all. Maxdlx

 

[kritter5150]

i went back to the viper belt today. inconsistent rpms. doesnt pull hard. clutches hot. it is a world of difference using the 8dn. only reason i went back to the viper belt cause the 8dn slid up and over my primary and the belt exploded after only 150 miles. can someone please tell wtf is going on?