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I need help w/clutching a 1992 v-max 4 that has psi quad pipes, that fancy cdi box that was made for them---can't remember the brand, and hauck head mod. I think hauck did some port work to the cylinders as well, to change timing. This is my friends sled so I don't remember everything exactly. I do know that he said it pulls well of the line to 7500 and then it just stays there. He had a heel clicker clutch kit in it and has changed clutching already a million times and it still won't go over 7500 rpm. Does anyone know how to clutch a sled with these mods? Does anyone have a good ballpark setup to try? Any help would be greatly appreciated. We would like this sled to work well this year.
 

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I need help w/clutching a 1992 v-max 4 that has psi quad pipes, that fancy cdi box that was made for them---can't remember the brand, and hauck head mod. I think hauck did some port work to the cylinders as well, to change timing. This is my friends sled so I don't remember everything exactly. I do know that he said it pulls well of the line to 7500 and then it just stays there. He had a heel clicker clutch kit in it and has changed clutching already a million times and it still won't go over 7500 rpm. Does anyone know how to clutch a sled with these mods? Does anyone have a good ballpark setup to try? Any help would be greatly appreciated. We would like this sled to work well this year.[/b]
The thing is, you are way modded here, so this is a hard question. You need the clutching chart from PSI just for starters. That should tell you a pretty good baseline and it should say what the target RPM is. 7500 could be correct. It sounds low but I can't be sure. The pipe maker determines the peak RPM, if you try to exceed the RPM design of the pipes you will lose power. My 96 Vmax 600 SLP pipes are designed for 7800 RPM, so 7500 might not be wrong for a 4 cyl.

The head work could change the power profile enough to require further re-clutching. I've only had experience in piping and de-piping with SLP products. SLP has the tech specs for all their products online, so hopefully PSI does too. The head work is an X factor for me, I don't know what to tell you.

Without knowing your peak RPM for those pipes you are in trouble. There is a small amount of room to tune by feel. I'd say if you are happy with the engagement RPM then you can try putting the secondary spring on a tighter setting (higher number). This should raise your peak RPM unless the primary clutch is not set up correctly. Yamahas don't have as many aftermarket clutching parts as the others and I found my Vmax the hardest to tune outside of stock specs than any of my other sleds. On the other hand it is quite easy and predictable to tune when staying within specs. Mine has a very low engagement compared to other sleds (3800), but plenty of torque to pull it. I would say your sled fits that description X2 so engagement RPM really should not need to be all that high.

I would not let it rev higher than 8000 RPM under any circumstances (unless your PSI charts say so) because chances are that is the top of your power band or slightly past. 7800 is probably the peak I would shoot for if guessing, but when you ride it if you are very aware you will be able to tell if it is losing power as your RPMs get to where you want them. This is a subtle thing because the power drops off slowly at first and if you're just barely past your power band everything will seem good but in fact you could be getting more power at just a little lower RPM. Typically, if your peak RPM is too high, the acceleration up to your peak will feel more powerful than actually running at peak, and running at peak will feel a little flat by comparison. That's not what you want.

If the engagement is too low I can't advise anything else except contact the manufacturers and pry whatever info you can out of them. Maybe someone here can answer this specifically but this is a pretty niche specific question. The general rule of course is that less weight on the same primary spring raises engagement and should push up your peak RPM too, but peak RPM depends on the setting of the secondary as well. Where you put the weight on the cam arm also matters for engagement, but I don't have the experience to comment on that. I believe that you do more to engagement when you change the weight on the inner part of the arm. But don't forget it's mostly about the total weight, and raising your total primary weight (on the same spring) will lower both your engagement and peak RPM.

There is also the good chance that your clutch is set up perfect but the springs are getting worn out. Or the engine could be losing power for some reason...or...well you get the picture. I thought for sure I had clutching problems on my Vmax this year on one of the last riding days of the year, like May 10. Wasted precious riding time changing the belt and tightening the secondary spring...I was just sure my spark plugs were fine even though I hadn't changed them all year and it was now May. Well after changing the plugs I then had to undo my clutching changes because it was the plugs all along. It *seemed* to be running perfect (start on one pull, great idle, perfect responsiveness and great low and mid-range power) on the old plugs and *acted* like the clutch wasn't shifting properly because it was struggling to get to peak RPM, but in fact the engine wasn't producing the power I thought it was. The plugs didn't even look that bad, they weren't fouled, they were just worn out. So just don't forget that sometimes clutching problems aren't really in the clutch.

Finally...if you really want this done right take it in for Dyno testing at the right shop and they will be able to determine your power band and tell you exactly what your peak RPM truly is (not just what it should be or was designed to be) and from that they can exactly determine your proper clutching. Depends on your budget. Good luck. And please make sure you are using the right fuel for this setup. It sounds like even premium might not be good enough...
 

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ULTIMATE V MAX 4 WEBSITE THIS FORUM IS ONLY FOR INLINE 4 BANGERS CHECK IT OUT

If the engagement is too low I can't advise anything else except contact the manufacturers and pry whatever info you can out of them. Maybe someone here can answer this specifically but this is a pretty niche specific question. The general rule of course is that less weight on the same primary spring raises engagement and should push up your peak RPM too, but peak RPM depends on the setting of the secondary as well. Where you put the weight on the cam arm also matters for engagement, but I don't have the experience to comment on that. I believe that you do more to engagement when you change the weight on the inner part of the arm. But don't forget it's mostly about the total weight, and raising your total primary weight (on the same spring) will lower both your engagement and peak RPM.

There is also the good chance that your clutch is set up perfect but the springs are getting worn out. Or the engine could be losing power for some reason...or...well you get the picture. I thought for sure I had clutching problems on my Vmax this year on one of the last riding days of the year, like May 10. Wasted precious riding time changing the belt and tightening the secondary spring...I was just sure my spark plugs were fine even though I hadn't changed them all year and it was now May. Well after changing the plugs I then had to undo my clutching changes because it was the plugs all along. It *seemed* to be running perfect (start on one pull, great idle, perfect responsiveness and great low and mid-range power) on the old plugs and *acted* like the clutch wasn't shifting properly because it was struggling to get to peak RPM, but in fact the engine wasn't producing the power I thought it was. The plugs didn't even look that bad, they weren't fouled, they were just worn out. So just don't forget that sometimes clutching problems aren't really in the clutch.

Finally...if you really want this done right take it in for Dyno testing at the right shop and they will be able to determine your power band and tell you exactly what your peak RPM truly is (not just what it should be or was designed to be) and from that they can exactly determine your proper clutching. Depends on your budget. Good luck. And please make sure you are using the right fuel for this setup. It sounds like even premium might not be good enough...
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Discussion Starter #6
found out it was the reichard cdi box we had on it. the box is fried. we are now looking for a new chip. anyone have one? one for 9000 rpm
 
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