steveg_nh

Hi All,

Curious to get some thoughts on this. I know it will be difficult to really say since you weren't here, but just curious what you think.

Earlier tonight, I removed my "new to me" Yamaha SX Viper 700 sled from my little utility trailer where it's been since I bought it last week, so I could put it on a new dolly I made for it (see pic).

Anyway, we backed the sled off the trailer with no issues and ran it up on the ramp once just fine. But we backed it down to adjust something, and the second time, I had a little issue. First, I forgot I had the parking brake on, so I wasn't going anywhere fast. Oops. Shut that off and on we went.

But as I was working the throttle we started getting smoke. Felt like the maybe the brake was still holding. Then we noticed it smelled a bit like rubber so we suspected the belt. Once we got it all situated we checked everything out and from we could tell, the parking brake was releasing just fine, and I can't imagine the regular hydraulic rear brake was stuck. We did notice some rubber shavings around the clutches, so we're thinking I was bit too easy on the throttle (and hard on the clutch) so it really wasn't grabbing, but was smoking the belt.

My buddy thinks it's just fine and that when I'm ready to go, I really want to get on it quick so the clutch engages quick and I'm not stuck kind of engaged, and kind of not. No feathering he said, whether Yamaha or any other brand. I figure it's the same as when I drive a stick car or motorcycle, but given that I wasn't "shifting" or actually working a clutch lever or pedal, I didn't even think about it.

Thoughts? Any questions that I can answer to put my mind at ease? We're supposed to get some good snow up here tonight, so hopefully it's ok and I'll prove that with some runs on the trails behind my house.

Thanks a ton!

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yamadad4

sounds like you just smoked the belt. best to put on a different one after you deglaze the clutch sheaves. more than likely there will be some serious black rings of belt residue on the clutches. some compressed air about the clutches will more than likely be a good idea. the belt was probably down in the secondary after the first moving attempt.

dont be surprised if your parking brake has a new attitude, some adjustment may be needed. been there, done that.

new belt and clean things up a bit and your good to go, unless for some reason the hydros are stuck. lift the rear of the sled and rotate the track with another set of eyes on the jackshaft.

fryedaddy

i agree sounds like you brake was stuck

steveg_nh

Thanks. So I have a few things to learn then...Deglaze the clutch sheaves? I know what you mean, but not sure what to use to do it. They don't show any signs of belt rubber on them though, they seems pretty clean. Is there a preferred way to do this?

With the compressed air, just blow around both clutches to clean out any rubber shavings?

The belt seems ok, no signs of wear. I don't do much heavy ridiing, just local on the trails behind my house. Do you think I should still do the new belt, or just see how it runs?

Lastly, you mentioned a stuck hydros. That, I have no idea what you're talking about. Would you mind elaborating on that a bit?

Thanks a million!

yamadad4

use a scotchbrite pad or light emery cloth and basically light sand the clutch sheaves. nothing coarser than 180 grit, 220 or finer would be preferred.

correct on the compressed air. you can even put some rags or paper towel in the belly pan under the clutch and spray the inners with brake clean.

if you had the park brake locked and you saw or smelled belt smoke, more than likely theres a flat spot on the side of the belt or a glazed section. use the same abrasive your using on the clutch sheaves and scuff the side of the belt. if you end up with a "clunk clunk" noise at lower speeds, that would be the belts' flat spot rotating through the clutches.

i was referring to the hydraulic brake system "hydros". depending on the care and condition of the sled, not uncommon for the caliper to have corrosion where the pistons insert and cause them to stick.

steveg_nh

Ah! Extremely helpful and easy to address. I would think the hydro brakes are ok. We had the sled propped up and were cleaning it out (running it) and the brakes were working REALLY well. I'd be surprised if they were stuck.

But what am I looked for when I look at the jackshaft? If the track spins freely, and brakes ok, could there be something else?

Thank you again! I'll inspect the belt and clean the clutch sheaves.

steveg_nh

So just an update. I cleaned the sheaves off. Definitely had some rubber residue on there. Otherwise, they looked good. A buddy of mine came over, who has a lot more mechanical knowledge of sleds than me, and he helped me out. We checked out the belt, and while it didn't have an obvious flat spot, it was glazed all over and showed signs of prefraying. His suggestion was to ditch it, install the backup belt, which was almost new, and buy a new belt for the backup. So I did that.

We also blocked up the sled and were able to freely spin the track, so it doesn't seem like anything brake related is locked up. While we were doing this, we inspected the track and made sure none of the studs were missing.

I admit I'm a bit nervous to ruin another belt when I try it again, but he feels strongly that it's fine and the reason it did it was that the machine just wasn't moving on the wooden dolly I made and since the belt was a bit worn, it wasn't grabbing...

So hopefully I'm good!

Thanks for your help.

yamadad4

just be sure that the belt is as far up in the secondary sheaves as possible before hammering the throttle. a few cycles with rear lifted will insure its properly seated.

when you get your new belt, be sure and wash it good with soap and water and scuff the sides a bit. along that note, if the spare your installing hasnt seen any action yet, you may want to clean and scuff it as well. from there, just take it easy for a few miles to give any belt a chance to break in.

as for the jackshaft, you really couldnt have done anything to it based on the scenario you went through. since its a new to you machine, take some time to check the chaincase fluid and gear and chain condition, or just change the fluid for peace of mind.

steveg_nh

Wash it with soap and water, really? The new looked nice and new, but didn't feel oily or anything. You think I should do that to it? It's in the spare holder now. I used the one that was the spare. It looks very good, but I don't think it was brand new. Not sure though if I should scuff it up a bit.

One question - we got the replacement belt on, but the secondary stayed separated once we got the belt on so it's sitting low int the groove. My buddy said once I start it up and the primary catches, the secondary will close up and be fine. But should it have stayed open? Should I try to get it to close?

We did check the belt we used for proper height, it was just slightly above the secondary so it seemed within spec.

We did check the chaincase fluid, and it was fresh fluid, you could tell. The sled was always serviced at the local powersports dealer, so it seems well cared for.

Thanks for the help again!

I will say this too - nothing to do with this thread - but I put some new plugs in it this morning, and ran it a bit. WOW. So much smoother and cleaner with fresh plugs. The seller told me it was time for new plugs. The insulators looked good though, not toasted, and the bottom of the plugs just dirty but no signs of combustion issues...

yamadad4

the belt will cycle up after a few rotations. your buddy and i are on the same page, learn from him. almost impossible to get the sheaves on the secondary to push the belt up after swapping belts. tug and pull if you like, but spin the clutches under power and its a done deal.

always wash and scuff any new belt. soap and water along with a scotchbrite and air dry. even scuffing used belts can add some life to them. although new belts may appear clean, you need to consider the fact there is a release agent added in the mold process and if you want the best from your belt, scrub this off.

spark plugs are relatively cheap at around $2 each, x 3 for $6. $12 if you keep three new in the holder on the side of the airbox. it is amazing at how well new plugs can alter performance. make sure you have the correct ones. BR9ES? dont rely on factory gap, check them yourself.

steveg_nh

Thanks on the belt sitting low in the secondary. When you said to be sure the belt is as far up on the secondary as possible before you get on it, it made me wonder if I shouldn't leave it where it is, but as I mentioned, he said forget trying to get it up without power.

Yup, BR9ES and I gapped them all myself this morning to just about .030, 6 of them. 3 new spares. Torqued 'em down to 14 ft lbs. Runs like a top!

When you reference scothbrite pads, are you just talking about the dish cleaning sponges? Or something like a fine sandpaper or steel wool? When you mentioned grits earlier, like nothing less than 220, that didn't sound like a cleaning sponge! I used fine steel wool for the sheave cleaning, making sure I didn't get any metal flakes from the pad in the clutches.

And any worries about using a soap that could break the belt down? Do you just use dishwashing (hand) detergent or something like some ivory bar soap??

I love to learn, and given that I'm not completely comfortable with sleds yet, I have lots of questions. Thanks for entertaining me!

yamadad4

dawn,the kitchen sink, and warm water.

green kitchen ones are good if they are fresh from the wrapper, not so much if you wife has used them for less important things. i use the red or gray from my auto body buddies, your golden with the steel wool, keep an extra wad in the tool kit just in case.

steveg_nh

thanks. I can see the sponge being strong enough to clean the belt but I'm surprised it's strong enough to scuff up the edges. You use the sponge for the scuffing too?

And it's not an issue to get a belt all wet like that?

Thanks

joshkidner

As long as its dry before you try to use it most use scotch brite pads or 220+ grit sandpaper. Ive used engine degreaser on a cloth and it gets the rubber off the clutch. Make sure it doesnt touch anything else other than the cloth and inside the sheaves. It will ruin rubber, lol

__________________
1987 chasis with 1985 597cc under the hood. Xtra-10, fox shocks, and a whole lotta speed!

steveg_nh

Thanks. I have some 320 grit wet sand sandpaper around. I'll use that to scuff then, rather than run out for the pads. Thanks!

steveg_nh

Done! Washed the current belt (which was the spare) and the new belt (which is now the spare)...squeaky clean and scuffed on the sides.

Thanks again for all the help, Yamadad4 and others!

joshkidner

Great!! Let it dry and take it for a spin! (of you got snow, which unfortunatly we do not )

__________________
1987 chasis with 1985 597cc under the hood. Xtra-10, fox shocks, and a whole lotta speed!

steveg_nh

Should be good now. There was a bunch of rubber on the clutch sheaves too, which I cleaned with steel wool yesterday. Spit shine clean right now! Unfortunately, no real snow at my place. About 3" on the ground, but only 6 miles from here got 9"! Someone doesn't like me! LOL. I figure I want a good 6-9 on the ground so I don't rip up my lawn. I have a studded track. Of course, it's tempting to just load it up and take it to a trail. Many are open now.

joshkidner

Your lucky. We have almost no snow and were in michigan! You go an hour in any direction of us there is 6in of snow. Dang storm went right around us!

__________________
1987 chasis with 1985 597cc under the hood. Xtra-10, fox shocks, and a whole lotta speed!

yamadad4

your kitchen is apparently stocked differently. my scotchbrites no not have a sponge attached. sounds like your good to go. think snow!