The clutch spring you seek is 37807-03. It is much heavier than stock but not near as punishing to pull as the SE spring. This is the Pink marked spring and was designed for the police bikes with a heavy duty clutch. I use one in my bike with Andrews 48H cams and have zero slip, even with a passenger. And, it doesn't require brute force to use.

 

Another question is how do you ride? Do you use the friction zone often? Try to sit at a red light without putting your feet down, play in cones or do tight turns using torque. If so you don't want Kevlar since they will glaze over and can't handle the heat. Carbon fiber is the way to go with that. Barnett clutch (who makes Harley OEM) is a cheaper option, Alto is even cheaper and has the lifetime warranty. Make sure you fill out the card for the warranty. May have to buy 1 more set of Alto clutch in the distant future for when you send out that clutch you won't have the down time waiting on new clutch to come in. Due to the increase in motor performance you should go with a heavier spring. Mic the frictions and the steels to see if still within tolerance. Check the steels to see if they are warped at all. Clean them up and save Soaking in oil for a nearly broke in backup clutch. If you want heavier grab with small friction window to pop through them gears fast... SE clutch kit is rather cheap with frictions and steels. Add Gaskets and oil for about 220 to rebuild. 250-260 if you add the SE spring to go with it.

 

I don't ride the clutch much. But I wouldn't want to risk kevlar anyway.
Thanks for the advice.

 

My bike is an 07 Ultra Classic with a stage two.
After taking the "Ride Like Pro" class I fried the factory original clutch. I'm pretty sure it was improperly adjusted from the PO. I replaced it with the Energy One Plus1 Kevlar with a heavy duty spring. The friction zone is much smaller but is still useable. The extra clutch lever pull is only noticeable in prolonged stop and go traffic. The hook up is amazing even riding two up with two large people. The kit was very reasonably priced. It's been in for a bit over a year now with zero issues.

 

That's an interesting comment! You have kevlar in your tyres and drive belt, it has also been used for many years in clutches, such as from Barnett. What risk are you wary of?

 

If you don't ride the friction zone much, Kevlar will be just fine. The riding like a pro style riding through cones or slow speed race type riding over say 5 minuets will overheat that clutch causing the glazing over and eventually disintegrate. It also causes the organic to burn up. If you do the heavy friction zone for short stents, you shouldn't have a problem. Doing the slow speed in cones we usually run 10-15 min with off and on friction zone then breeze out the bike riding a couple good laps around the corse and park to let the bike cool off for 45 minuets + before starting over again. That is where Kevlar and organic will not work. OEM clutch was explained to me to be the best made clutch for lasting. Some of the people I ride with have the original clutch 85k miles later.

 

I was using the info garnered from another comment (above somewhere) that if I ride the clutch in stop and go traffic it could cause clogging and such. Was depending on others knowledge because I am new to this in motorcycles.

Here's the info I was quoting from Cold rain:
"Another question is how do you ride? Do you use the friction zone often? Try to sit at a red light without putting your feet down, play in cones or do tight turns using torque. If so you don't want Kevlar since they will glaze over and can't handle the heat."

 

That's interesting! I've only recently installed a set of Barnett plates, although haven't ridden much with them yet. I'll keep that in mind, thanks.

 

OK. I installed the vpc as well as the SE spring plate. Holy cow, what a difference. The bike doesn't have much clutch play anymore. It grabs harder and faster. It fixed my problem that I was having with slippage too. Before the change the clutch was slipping under heavy throttle in 4-6th gears. No more troubles with that.
The SE spring isn't as heavy as some people made it out to be. I have no problems in stop and go traffic with my hand cramping or getting tired. It was a bit stiffer, don't get me wrong. It's just not as heavy as some made it out to be. I love the addition of the vpc and SE spring plate. It saved me a bunch of money by not having to replace all the plates and was easy to do.
Thanks again for the advice.

 

If oil is still dirty on the next change, the clutch is likely slipping.