Yamitriple
Member
I've read everything on clutching on TY and still need a boost for my setup. Anything is appreciated guys. With that being said my sled (97 sx700) is completely stock besides power inc CD pipes. Sled is mechanically sound and motor is fresh( just to rule that out lol). I'm running 89l weights with 6.1 g in the tip, stock spring with 1 engage shim and 15mm rollers. Secondary I'm running 46/41 stock spring set to 60 wrap with stock deflection shims. Engagment is 3500 and shift out is 83-8400 which I can feel the motor fall off pipe after 8200. The sled doesmt have enough bottom end pull and acceleration, but has great top speed if u got the room. Just takes way too long to get there. I'm definitely missing the power curve of this setup and need some advice.
Yeah, I can see why. Your engagement speed is about 700 rpm too low for my liking at least. I think it is like this (correct me someone if I'm wrong), it grabs early and it is like driving a car in a too high of a gear. Had that condition on my vt 500 once.
Yamitriple
Member
So stiffer primary spring would be a good place to start? Also I'm sure I need to pull more weight unless some other aspect of my clutching is letting rpms climb too high. All together I'm pulling about 50g per weight. The 89s are thick at the base skinny in the middle and the only hole is in the tip of the weight which I've added 6.1 g to. The shift profile can be found in the tech pages, I believe they are 43 g without any rivets
Yes a spring with a higher inital rate.
Yamitriple
Member
Can I get away with engagement shims? Possibly another 1 or 2?
Yamitriple
Member
Also would the helix I'm running be sufficient for the weight or should I go for a steeper initial? Or possibly just a shallower finish to obtain better back shift? Back shift is less than par for sure seems like clut has have to catch up after I let off full throttle and punch it again
Your helix is very shallow.
In comparison, I run a 51/43 in mine with bender pipes and 89L weights, and I run around 85-8600.
In comparison, I run a 51/43 in mine with bender pipes and 89L weights, and I run around 85-8600.
Yamitriple
Member
I'm thinking with more weight in my primary I would need a steeper angle with more spring tension to keep the secondary from closing too slow compared to how fast my primary is opening after I let off, then punch it again it will need to catch up so to speak. Can I get anyone to confirm or correct me on this?
Not quite how it works.
More weight in primary increases clamping force on belt, less slippage, less RPM.
Shallower Helix (like a 45) would be more Rpm than like a 47.
How do you have 6.1 Grams in those 89L weights? Using washers as well? Heaviest rivets are 4.5 grams.
I think this is the info you need.
https://totallyamaha.com/snowmobiles/aaTECH/tuningpics/powincsx.jpg
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Yamitriple
Member
They are heavier metal rivets, not sure what metal schmidt bros made them. And that makes sense I just can't seem to understand y the sled is still above target rpm. With 4.5 g rivets I would hit 8500, the 6.1 g only brought me down to 83ish. I feel like I'm pulling more weight than what I should have to already. I have stock gearing i wonder if maybe that could be the issue. I followed Turks tips to start with the PI pipes which said stock gearing with the 89l w/4.5 rivets and stock springs and 47/41 helix. So unless he was a lot bigger dude than me I can't understand why I'm having trouble keeping it below 8200 and why my mid range and "pull" is lacking so bad...
Yamitriple
Member
I'm half tempted to just take her back to stock, but I know these pipes will make more power than stock I just gotta get em dialed in.. so naturally I'm hesitant to do that when i feel like i must be close to the right setup. I just can't believe that what PI recommends and what Turk recommended are so far off from what I've personally experience with my machine and these pipes
Can you confirm what color primary spring you are using?
How many miles on the sled?
How many miles on the sled?
Yamitriple
Member
5300 km and it has a stock primary spring for the 97's whatever that may be. Clutches are freshly rebuilt with bushing buttons and rollers. Springs were tested and are in spec as far as I know. Schmidt bros did the work
Yamitriple
Member
It's a W-S-W primary spring and and green secondary spring
Rpm consistent as soon as you hit it to top speed?
A couple of bucks
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Have you personally counted teeth in the chain case? And you can say without a doubt what they are?
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Yep, if it’s geared down even 1 or 2 teeth, that alone could be the over rev.
BornYamaha
Member
Sounds like you have two problem. Too low engagement for the engine that is peakyer with the pipes and a higher end overrev. I am not sure were those pipes are suppose to run at but it sounds like you are saying around 8,200 rpm. Please confirm that. Unless you do something like an engagement notch (Not Recomended For Trail Use) on the weights you will never be able to get the engagement up high enough. The shims don't move it much. You have a 97 so you should have the short primary cover. Unfortunately there are no springs available from Yamaha, for that cover, that have a high preload rate. (Unless someone here knows of an aftermarket one that does). You are going to need to find a tall cover from one of the later primarys first. They bolt right on. Someone on here should have a used one you could buy. Then you can use a spring with a higher preload that is available for that cover. Looking at the old max perf catalog that somebody so nicely scanned on here. It looks to me that a
Blue-White-Blue PN 90501-583L0-00 would be a good start. The total force is nearly identical to yours and the preload is up from 35 to 45. I think you may still need to add shims to get the engagement up were you need it. This spring will probably bring your shift rpm up some as well, but you need it to be higher at take off. Now that the engagement should be higher you will need to focus on getting you shift rpm back down where it needs to be. There are many ways to do this. The first thing to try is to add as much weight at the tip of the clutch weight as you may need. If you can't get enough to do the job you could try more in the middle hole but that might be too much for the midrange. Your next options to bring top rpms down would be steeper secondary cam angles and weaker secondary springs. The bigger the number on the angle the more it should lower your rpm, but at some point it may not backshift as well. The mult-angle cams that others here have mentioned can help with the backshift and effect the shift rpm at different speeds. If you are close you may just want to try the weaker secondary spring option with less wrap first. I have kind of listed these things in order of cost to some extent. Buying a bunch of secondary cams can get expensive in a hurry. There is also the option of going to different weights like Heelclickers which work great, are very adjustable, and also are kind of expensive. You would still need to do alot of experimenting with those. It just may be easier to put in and take out screws for the weight adjustments instead of using the Yamaha weights with the rivots. There are many ways to do this . They all take a little experimenting. I definitely believe you need to make sure you can get your engagement where you need it first with the Yamaha weights then go after the rest. If you just get your shift rpm were you want it first everything you do to help your engagement will throw off you shift rpm. ( Last statement does not apply to heel clickers or other adjustable weights.)
Blue-White-Blue PN 90501-583L0-00 would be a good start. The total force is nearly identical to yours and the preload is up from 35 to 45. I think you may still need to add shims to get the engagement up were you need it. This spring will probably bring your shift rpm up some as well, but you need it to be higher at take off. Now that the engagement should be higher you will need to focus on getting you shift rpm back down where it needs to be. There are many ways to do this. The first thing to try is to add as much weight at the tip of the clutch weight as you may need. If you can't get enough to do the job you could try more in the middle hole but that might be too much for the midrange. Your next options to bring top rpms down would be steeper secondary cam angles and weaker secondary springs. The bigger the number on the angle the more it should lower your rpm, but at some point it may not backshift as well. The mult-angle cams that others here have mentioned can help with the backshift and effect the shift rpm at different speeds. If you are close you may just want to try the weaker secondary spring option with less wrap first. I have kind of listed these things in order of cost to some extent. Buying a bunch of secondary cams can get expensive in a hurry. There is also the option of going to different weights like Heelclickers which work great, are very adjustable, and also are kind of expensive. You would still need to do alot of experimenting with those. It just may be easier to put in and take out screws for the weight adjustments instead of using the Yamaha weights with the rivots. There are many ways to do this . They all take a little experimenting. I definitely believe you need to make sure you can get your engagement where you need it first with the Yamaha weights then go after the rest. If you just get your shift rpm were you want it first everything you do to help your engagement will throw off you shift rpm. ( Last statement does not apply to heel clickers or other adjustable weights.)
A couple of bucks
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Yamitriple
Member
No I have not personally counted and the rpms seem to slow down at around 8g and climb up from there. Also I believe I can use a Yellow silver yellow primary spring with maybe 1-2 more shims. That spring is a little heavier. As far as the secondary maybe try a 51/43 with a little more preload for the back shift?, also would it help if I switched to 14.5 mm rollers to gain more up force after the switch to the yellow spring and shims? I'm not sure I can go any heavier with the 89Ls since they only have one rivet hole in the tip.