Finally got around to putting a new top end in my 04 viper mountain and I’ve been looking into the clutching and gearing specs. Chart I have says “standard” under 8000-10000 feet. Does this mean all of them came stock with this setup? Mine did come from Colorado so I would assume it’s setup with those specs. I live in Maine and I’m riding under 2500’ so I’ve gotta do some tuning to the clutch and gearing,(carbs have been dealt with) how much of a pain is it? I’ve never messed with clutches really but with some help from this forum I was able to successfully rebuild the top end.
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Have you ever had the primary off? Probably the hardest part is taking the clutch off the engine. The clutch is usually very stuck on the end of the crank.
I have not this sleds kinda new to me. Stupid question, what would happen if it were ridden the way it is? Not much power or would I have a grenade on my hands?
it would over rev and be down on power. if using yamaha weights/springs, you can do it without pulling the clutch off the crank.
True it can be done on the machine. If he does want to take it out to more easily work on it, I suggest the hydraulic method. Which is tipping the machine on its side, filling the orifice that the clutch bolt threads into with water then using a M14 puller taped with teflon to hydraulically push the clutch off. Its a tapered shaft and the clutch seems to snug itself onto the crank. The hydraulic method helps spread the clutch as it pushes it off the crank end.
Only thing is I wouldn't use the clutch bolt, m14x1.5 clutch puller instead. Something like this
Only thing is I wouldn't use the clutch bolt, m14x1.5 clutch puller instead. Something like this
Chart says the only thing I need to do is put rivets in and change drive gear. Does that sound right? Gonna order some rivets but how many will I need? Looked around and it seems pretty straightforward. Probably will try and take the clutch off. Changing the drive gear doesn’t sound quite as easy. Does gearing only impact speed or am I wrong? Thanks for the help guys!
The drive gear isn't too bad. I'm going by my srx700 as I don't have a viper but I think they are similar enough (someone correct me if I'm wrong) After the muffler is out, I think its as simple as unbolting the chaincase cover (which oil will come out all over the bottom of the sled). When you take off the gears make sure to take notice of which direction things go on, where spacers go etc. IIRC some things can go together wrong if you're not careful. There's a couple of bearings in the chain case you can replace while you're in there. Tho they may be ok as they run in oil.
That doesn’t sound bad actually. Thanks again! Would it be 9 Rivets for the clutch?
mod-it
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That's the first chart I've ever seen that shows different gearing for different altitudes. I thought all Mnt. Vipers just came with 21-40 gearing. Mine did. I would be surprised if all dealers are expected to find out what elevation the buyer plans to ride, and then they put the sled together from the crate with specific gearing according to what elevation the customer said they were going to ride?
I have an '03 Mnt. Viper, except I have triple pipes and an air mod done to it.
Mine has 21-40 gearing, and all my clutch components are factory with the exception of a 43° helix rather than the stock 45°, and I have added heavier rivets to the factory 8dn-10 arms.
It seems odd to me that the chart you posted shows a whole two teeth bigger on the drive sprocket, and also 4.5 grams in both the inner and outer holes of the primary arms. That seems like a substantial amount of gearing up and adding weight to reel in potential overturning of peak rpm's.
At any rate, there are 3 weights/arms in the primary. Each has one inner hole and one outer hole. If you follow your chart, you'll need to put in a 23 tooth drive sprocket (I'd wager good money that you have a 21 on it right now), and you'll need six 17.2mm steel rivets (w/out hole, 4.5 gram rivets). You'll put two in each of the 3 primary arm weights. You can simply get a proper sized punch and knock out the old rivets. Install the new ones by peening the thin end, or some just squeeze them in a vice to mushroom them to a point they swell enough that they won't come out.
If it still overturns rpms at that point, you'll either need to gear it down more or buy heavier primary weights, such as 8dn-20's.
I have an '03 Mnt. Viper, except I have triple pipes and an air mod done to it.
Mine has 21-40 gearing, and all my clutch components are factory with the exception of a 43° helix rather than the stock 45°, and I have added heavier rivets to the factory 8dn-10 arms.
It seems odd to me that the chart you posted shows a whole two teeth bigger on the drive sprocket, and also 4.5 grams in both the inner and outer holes of the primary arms. That seems like a substantial amount of gearing up and adding weight to reel in potential overturning of peak rpm's.
At any rate, there are 3 weights/arms in the primary. Each has one inner hole and one outer hole. If you follow your chart, you'll need to put in a 23 tooth drive sprocket (I'd wager good money that you have a 21 on it right now), and you'll need six 17.2mm steel rivets (w/out hole, 4.5 gram rivets). You'll put two in each of the 3 primary arm weights. You can simply get a proper sized punch and knock out the old rivets. Install the new ones by peening the thin end, or some just squeeze them in a vice to mushroom them to a point they swell enough that they won't come out.
If it still overturns rpms at that point, you'll either need to gear it down more or buy heavier primary weights, such as 8dn-20's.
Thanks for the input, I was also unsure about how a dealer would go about that. If the chart is correct I shouldn’t have to pound out any rivets just put them in. Might just leave the chain case as is and see how it performs. I kinda thought they all would have been geared the same until I found that chart.