Hitting rev limiter hard with gates belt

[Studroes144]

Is this rev limiter thing something new? Keep a close watch on your "leaves" because if you are now applying too much power too quickly you could be just blowing off the track ie: doing a burnout

That's exactly how my viper was, started with gates belt and stock 43 helix and spring. Loosened spring wrap some, then some more, then went up to a 45, then to a 47 helix and have that at 6-1 with stock spring. Power still almost comes on a tad too fast and hard to get traction. Going to a 50/46 next, hoping that is the setup I need and can fine tune between a few different secondary springs. I also have a higher rev limiter and clutching for 93-9400 so a few hundred rpm low doesn't have any real negative affect on it since it's still making great power. A few hundred rpm low below the stock rev limiter can easily pull it out of the power.

 

[Studroes144]

Yes when running 8dn /8jp I never wacked the Rev limiter on launch or at all. Since the gates belt I am hitting the limiter hard... I like the feel of the gate so I'm going to clutch to accommodate

Depending on clutch weights and weight placement there very easily can be a certain amount of belt slippage happening with the 8dn or 8jp, naturally the first thought would be that if the belt is slipping than it'd hit the rev limiter easier but not the case, if the belt is slipping it's not loading the engine the way it should and actually making the sled build boost slower and less consistent. I can about guarantee that you aren't slipping the gates belt and in fact the grippy belt is bringing on the power that much quicker and your turbo is really liking it. Before you start adjusting weight I'd definitely give it more helix and then tune accordingly. Like I mentioned earlier the apex used a 51/43 helix which can be found cheap. I have a straight 47 in mine now and if memory serves me correct I believe it was the stock helix out of an srx or that era of the 2 stroke triples?? Either way I bought it used off eBay for $20 and I'm sure u can get an apex one for around there too, they're just oem Yamaha helix's.

 

[yamamarc]

Depending on clutch weights and weight placement there very easily can be a certain amount of belt slippage happening with the 8dn or 8jp, naturally the first thought would be that if the belt is slipping than it'd hit the rev limiter easier but not the case, if the belt is slipping it's not loading the engine the way it should and actually making the sled build boost slower and less consistent. I can about guarantee that you aren't slipping the gates belt and in fact the grippy belt is bringing on the power that much quicker and your turbo is really liking it. Before you start adjusting weight I'd definitely give it more helix and then tune accordingly. Like I mentioned earlier the apex used a 51/43 helix which can be found cheap. I have a straight 47 in mine now and if memory serves me correct I believe it was the stock helix out of an srx or that era of the 2 stroke triples?? Either way I bought it used off eBay for $20 and I'm sure u can get an apex one for around there too, they're just oem Yamaha helix's.

Thanks studroes so you think I should just try the helix without changing weight or Springs? Maim (member here ) said he had a apex helix I could try he also has a 51/40
I really don't think the belt was slipping my clutch were nice and shiny clean after my last ride

 

[yamamarc]

This is my current set up
Primary blue white blue spring
Weights 8du-10
Rivets 17.2mm steel in tips
13.9 mm steel in mid
17.2 mm steel with hole in heel
Secondary white white spring 6-1
Helix 8bv31 43 deg

 

[Studroes144]

Thanks studroes so you think I should just try the helix without changing weight or Springs? Maim (member here ) said he had a apex helix I could try he also has a 51/40
I really don't think the belt was slipping my clutch were nice and shiny clean after my last ride

I'd definitely throw that 51/43 in there and just try it. When I setup my osp weights with the stock secondary helix and gates belt I went from 6-2 and loosened up to 3-3 then just keep putting steeper helix's in and adjusting spring wrap until I settled at a 47 at 6-1 and never once adjusted weights and rpm didn't drop a bit, now it's not going to be an exact comparison cuz I'm at 10 psi but I'd still recommend trying it

 

[RJH]

Agreed...my STX banged off the rev limited until I fed it a steeper helix...

 

[maim]

heck i have a bunch of take off helix floating around if you want to try them. did not label most of them but sx500r, sx venture 700 power valved, sx viper, rx war, apex xtx and rs venture gt is what they came from.

 

[larrypolaris]

This has my attention. Don't you guys find it odd that adding the Gates made it hit rev limiter on launch? Would think it would have done opposite since it brought top rpm down or usually does vs 8dn. Do you think the stickier Gates also slows shift down which is why it's now hitting rev limiter on launch?

I installed a Gates 40c4340 at the beginning of the season. Just to try it out.
I was expecting a RPM drop. But to my surprise I was pulling max RPMs and was bouncing off rev limiter also.

I have ~1400 miles on the belt. It is holding up well. The clutches look pristine clean.

 

[yamamarc]

I installed a Gates 40c4340 at the beginning of the season. Just to try it out.
I was expecting a RPM drop. But to my surprise I was pulling max RPMs and was bouncing off rev limiter also.
Did you just and weight to the heel of your weight.. how did you get it back in range?

 

[jeffgilbert]

i also ran into a similar situation with the gates 8jp version and turbo sled

 

[yamamarc]

i also ran into a similar situation with the gates 8jp version and turbo sled

What did you do to correct

 

[jeffgilbert]

nothing yet lol i did load my weights right down big time and it stopped but it was under revving and i haven't had decent conditions to test this year

 

[larrypolaris]

My sled is a non turbo sled. But I have a SLP header and can, and a Excel intake.
I am running Hauck VP weights and have them maxed out with my set up.
I was running a 45/39 helix. I put in a 46/40 helix to drop the RPMs.

 

[RJH]

So..a longer or wider belt will change where the ramp arm sits on the rollers...as you move.

With a longer or wider belt it will load the clutch...a short belt will move the roller closer to the start for a longer period of time.

very hard to feel on a 4/...I think..

My 43 bounced off at 9300 ish..then pulled down to 7200 SRVIPER..which makes less HP than a SW..however the bolt circle may be different on a SW. so different attack.