Friday, November 21, 2008

Custom Clutch Spring

Actually this has to be written about 5 month ago. But sadly at that time I don't have much time to spare.

The story begin when I change my scooter clutch with the brand new one. Bought a set of clutch and the clutch bell (clutch house or whatever it call). I must change the clutch because the old one had damaged when I tried to climb up a bridge. The bridge is not high, but I had to stop my scooter on the foot of the bridge because the traffic is stuck; my scooter incline position is about 35 degree with full of bagage and tandem with my wife. When the car in front of me is moving, I tried to open the throttle, but its to heavy for my scooter, and I open it a little wide; my scooter is moving and pass the bridge.

But there is something wrong after it, there is a vibration when it come on a stop and go traffic. Oh no, I think the clutch is burning. The vibration getting worse and worse, and I have to get used to it after the parts that I ordered is ready stock.

After the clutch is ready, I switch the old clutch with the brand new. Nah, it's done. Clean up the tools, and take some break.

Now, time to test the new clutch performance. I know that the new one is a stock, so I don't expect any increase on the performance. Turn on my scooter engine, and run it on the street.

First impression is, the brand new clutch is very poor on the performance. it need very high RPM to start the scooter to engage. This is very bad for the fuel consumption. But let us make an exception for this because it is a brand new clutch and it must be the clutch shoes didn't sit properly on the inner clutch bell. Let's test it for a two week, if there is no change on the performance, then I would do something about it.

1st week is very bad, fuel consumption become doubled than regular. I hate it so much, the scooter performance is very poor indeed. It take lot of time for my scooter to engage, the exact RPM is about 4800. And on the 60kmh, it need 8000RPM; regular is 6000RPM. Hope next week will be better.

2nd week is good, but not good enough. still my scooter engage in a high RPM about 4500. Usually my scooter engage on 4000 RPM.

I can't wait any longer, I must do something to make it good or better than before.

I think the brand new clutch had a problem on the friction point that make the clutch can not stick tightly on the clutch bell. So how come can I fix this problem. I think the best way to solve this is to change the clutch spring with the softer one.

I need a softer spring than the one on the after market. The solution is, I must make a custom clutch spring.

I search on the market any spring that softer than the stock and it must be steel not iron, and the length quite similar. Got it! Time to change the clutch spring with this one.

Prepare some tools:
1. 8mm socket
2. 17mm socket
3. Clutch special tool
4. Big sized minus (-) screw driver

- Open the CVT cover with 8mm socket and remove it.
- Open the front pulley with a special tools and 17mm socket, or if you has an impact wrench then open with it.
- Remove the front pulley.
- Open the clutch bell with a special tools and 17mm socket and remove it.
- Pull the clutch from the engine.

As you can see the clutch isn't touched the bell inner surfaces properly, about 60%, signed with the black surface on the shoe.

- Remove the clutch from the sheave with clutch special tool opener.
- After that, we must remove the three pieces steel ring with a big sized minus screw driver and remove the plate.

- Separate the clutch shoe from where it sit with the screw driver

- Now you can see the clutch clearly and remove it

This is the stock clutch spring:

This is the stock and the custom spring:

- Plug the custom spring on the clutch shoe, and stick everything together backward.

Done with that, lets test it right away.

Turn on the engine until it hot enough, and open the throttle while I see the RPM meter closely. I feel the scooter is engage, and you know what; the scooter engage on the 3500 RPM.