ATV Florida Forum

Its a woodruff key that advances your iginition timing by 6 degrees making better throttle response and a lot of torque.  Has anyone here tried this or know a friend that has done this mod?  I am just wondering what happens to your topend and how the quad performs after installing it.

I have one installed on my current bike and on one of my old bikes. Much better throttle response and bottom end torque. I don't think it does much on the top end, if anything at all. You will get higher oil temps if you are slow trail riding or riding technical hills. I run Tinner air scoops which helps a bit. Some people say you should not run one with higher comp. but my last bike had 426 bore with a 11 to 1 comp. and I had no problems.
It is a easy install. You will need a left side gasket,starter cover gasket and the key and bolt that comes with the kit.


Make sure you turn the flywheel all the way to the left before you tighten the bolt.

I called Curtis Sparks and they said high compression is 12.5:1.  So under that they said the key is fine.  Right now my 3rd gear doesnt pull real hard from the bottom end of it.  Its better with the mods I have but I would like more to it.  How would you rate the gain compared to a slip on exhaust and jetted properly or a better flowing air filter with the air box lid removed and jetted properly?

Hard to say? I think you would get back the bottom end you lost with the filter and pipe if not more.

my pipe added low end and a bunch or torque compared to stock.  Just wondering how it compares to other mods.  Like does this do a lot of is it minimal?

All bike's are diff but, most bike and trucks for that matter lose a little on the bottom when you free up the exhaust. On a torquey motor like the 4oo you don't notice it until u get into 3rd and 4th gear. I'm glad you got the gains you did with your pipe. I have never had the same.

so will I notice the key a lot in 3rd or 4th gear?

No, thats not what I meant. I was saying you notice the loss of torque from your pipe more at the bottom of 3rd and 4th gear.

The timing key is a easy, cheap power gain that you will notice alot more than removing your choke.

It take's less than a half hour.  Just do it.

I bought it 2 days ago it should be here anytime this week.  Now I have to buy gaskets or I could try the old method of using the cardboard stuff from packs of beer and cutting it to fit

I would just go with new gaskets so you dont have to worry about it