Has anyone tried the HPD plain spring in his/her Scrambler 500?? I have been playing with different primary springs to go along with the rest of my clutch kit. It has a Hot Seat clutch kit ( I know alot of you guys hate hot seat ) I am very pleased with it's performance, but ever since I got a tach I don't like the fact that it doesn't engage 'till 3,200 RPM. It's a 4-stroke, I knew I was losing low-end torque. So, I tried a Polaris white & it dropped the engagement to 2,000 but it doesn't have the full shift tension to get the engine to rev out. It now will only rev to 6,000. The Hot Seat spring revved to 6,800-7,000. I have done my homework on HPD spring rates & see that the plain primary has a low engagement weight, but a quite high full shift weight. So any real world info would be greatly appreciated.

 

Check out the EPI pink spring. It has the stock engagement but higher mid to top rpm's. Yoy dont want to go too high because the belt will eventually slip and the motor will rev to high.

 

I ended up going with a Polaris yellow and 50.5 gramweights to get mine to the point I wanted (top rpm 6750 engagment 2200) What are your weights?

 

Not positive on the weights. I'll have to look & see. It's whatever the Hot Seat kit comes with.

 

catman check in my pics i have polaris spring part numbers and a chart that i just uploaded not sure if it helps. plus rickritter has a spring chart in here aswell to give you some numbers. just waiting on aproval

 

Thanks to all so far. I looked up EPIs spring rates on their site. The Pink appears to be just a step up from the Polaris white. It would give me a lower engagement, but the full shift out is still below the Hot Seat spring that came with my kit. The Hot Seat spring is 60/200 lbs.

I totally get what 2manytoys is saying about too high a full shift, especially on the 4-stroke. See thats why I was thinking of the HPD plain, it's numbers are 32/235. A good low engagement, but maybe too high of a full-shift for the 500???

Keep the info coming.

 

What is your secondary set at? If it is at 1-1 try 2-2 before changing springs.This will get your rpms down some too.If the engagment with the spring you have is good try to fine tune it in to get youur rpms down.

 

I run the HPD6plain spring good spring engage about 50 shiftout 215 good midrange pull with this spring too , I actually think it engages a little lower than it is rated. I was running the HPD green for awhile but the 145 full shiftout was not to my liking or riding style

 

Bravops,

CAnt read the spring chart. It is way too small to read the letters.

 

My wifes bike has a HPD plain with s53 weights. This is the perfect setup for her. I used this set up for a while as well until I got the high engagement bug. This was with a HPD trail mod. Ours are 400's though.