VMAX 600 clutching

jfh51

New member
Joined
Nov 15, 2005
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2
I have been working on my wifes 600. The clutches are clean and aligned. I have lowered the top gear to a 19 tooth. I still have the 8DG weights with weight added and also I have lowered the starting tension of the spring. The wide open RPM is ok, however I am not happy with the low end slipping of the primary clutch with this set up. The drive clutch gets very hot when running at lower trail speeds. Running the hard Yamaha belt. Looking for suggestions to get the clutches to "hook up better" on the low end. Thanks.
 
Welcome.

Can you provide more detailed data. What sled is the 600? What do you mean the "Hard Belt"? When you added weight to the weights what was added and where?

The front should not get hot. Hot is bad.

Has any normal maintenance been done to the clutches? Springs and replacing worn out stuff?
 
More Info

Thanks for the reply.
It is a 2000 Vmax 600 deluxe, 600 tripple. The 8 DG weights have 3.6 grams added to the inside hole and 4.5 grams in the outer hole. Running the Yamaha 8DN belt. Red secondary spring wrapped 60 degrees. Clutches have been serviced and the clutch faces lightly sanded. Primary spring is gsg (this has 10 kg less staritng rate than stock. The problem is when running at slow trail speeds (less than 30 mph) At these speeds there seems to be excessive slippage in the primary clutch. High speed performance is great running at 8400 rpm. I am thinking that it is the curve of the 8dg weight causing the problem.
 
The "10kg" less is the preload. The GSG is 35kg preload/2.75kg-mm rate/126kg total force length is 87.4mm the YGY stocker is 40kgpreload/2.5kg-mm/123kg total force with a 89.4 mm free length.

I'm not much of a clutch guy but picturing the way the clutch works the weights work against the rollers acting like a lever against the spring to move the sheave. Since the spring involved not has a increased rate .25kg-mm more force is needed to counteract the spring for a give rpm. Where the weights are in their throw has an effect on how much force they apply. I.E. the beginning 10mm of the arc the total force starts at 50kgt and ramps up to 250kgt and stays there. (Your 8DG weights are very similar to my 8CR's but are 3.75 grams lighter.) What I am getting at is since your tuning issue is at low speeds and the secondary is sensing high amounts of torque it is running the belt high on the secondary and low on the primary. There is just not enough force produced by your combination to grab the belt at that speed.

The springs run about $16. You might want to try out the stock YGY spring. Also your secondary should be wrapped to 80* for trail use. Looking at the chart on the clutch tech page your 8DG's came with 10.6g inner and 13.9g outer.

Maybe one of the clutch veterans will chime in on this one.
 


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