How to take front sprocket off? What size screws for case saver?

Im changing my chain and sprockets, and also buying a TM Kit for my bike. Along with some radiator guards, skid plate, just some other goodies. :excuseme:

While Im doing all that I got a couple questions. 1. How to take front sprocket off, I notice Yamaha has a washer type thing "bent" over the nut, do I just bend it back, and take it off? Would using a Impact wrench be better for this job? We just bought all new air-tools and I wouldn't mind putting them to good use! Is there any tips or things to look out for when changing sprockets and putting on a chain? Im not going to be cutting the chain, Im using stock 13/49 gearing, with a 114 link chain.

Also, I didn't fully strip the heads on my case saver/plastic guard screws, but that soft aluminum phillips head screws are getting bad, what size screws are they, so I can head down to local hardware store and pick up a couple more, hopefully allen heads if I can find them. I want to still use the cover, I know some of you guys take the cover off and just use the case saver (smaller screws), but I like to have it all on...covers obivously there for a reason, and it don't hurt anything so I don't mind it.

Thanks AGIAN.

The bolts are 6mm, 1.0mm thread pitch. Match them for length if you want to keep the cover.

If your impact wrench has the juice for the job, use it, but take this advice: use the chain and rear wheel to hold the sprocket, or use a holding tool like Yamaha's flywheel holder, or a big pair of pliers and a rag, or even your hand (careful!), but DON'T put it in gear and put all that slamming against your transmission.

The cover serves three purposes: It makes the lawyers happier because it's harder to get your toes and fingers in the chain, it slows down front sprocket changes, and it packs up with mud so as to jamb up your driveline when you ride in wet conditions. the latter is why virtually no one at the races has one on their bike.

Alright Gray, thanks agian man. Lol, maybe I won't use the cover, your right...does get dirt all clogged up in there now that I think of it. What size length if I don't use the cover?

What do I hold with the rag, or pliers if I use them? The front sprocket? Could I get it off without a impact wrench, or is it really tight? What about torque, how tight do I want to screw the new one back on?


Alright Gray, thanks agian man. Lol, maybe I won't use the cover, your right...does get dirt all clogged up in there now that I think of it. What size length if I don't use the cover?
The bolts for use without the cover should be a good grade (10.5 or 12.5) and about 15mm long.
What do I hold with the rag, or pliers if I use them? The front sprocket? Could I get it off without a impact wrench, or is it really tight? What about torque, how tight do I want to screw the new one back on?
Yeah, hold the sprocket. Don't you have a manual? It's 54 foot pounds, dude. Look it up.

I always use my impact wrench when I'm at home, but when there's no air, I lay a hammer across the swing arm, through the spokes as close to the rim as I can get it, and crank it off with a wrench (the chain needs to be there, obviously).

Alright, so I will just have my Dad help me out with holding the sprocket while I use my impact wrench, yeah, I have a manual, as soon as I asked you that I was like "oh, ill just look it up."

Thanks agian.

On the case saver bolts, I striped mine and went to Lowes and got some good Allen heads, good to go for many moons

With the chain in place, just have your dad stand on the rear brake.

It's also not a bad idea to have a new washer(the one with the tab that is bent against the nut). They were only meant to bend once.

Alright, I will pick up a new washer, I will just go and compare while Im at the hardware store looking for screws for case saver.

Thanks guys.

the stock screws stink, I stripped mine and had to use a impact wrench to get them off. Replace them with stainless metric 6mm. get a few diffent lengths as if you ditch the plastic cover the length of the bolts will need to be shorter.....stainless do not rust the rest will. :excuseme:

I would suggest going to cycle gear and getting the small box of misc. metric bolts they sell for bikes, rather than home depot because, but that's just me.

You will need to obtain the washer from Yamaha. It is a special lock washer that fits the splines on the shaft. When the tab is bent over, it locks the nut so it can't fall off. This washer has a second tab. You could reuse it if you position the washer so that the previously unused tab lines up with a flat of the nut when tight. Takes a bit of trial and error.

Yeah, couldn't I just bend a differnt side of the washer. Thanks.

you can - and /or the replacement washer is about not foget to install the star washer underneith it -

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