HOW TO- Sparks Advance Key Installation

[MAKO19]

Originally posted by Dangerous400EX
When the key is in right the fat part of the key will be flush with the crank. The offset, or narrower, part will be the only part sticking up.

Make sure the red portion is pointing away from the bike of course.

My key way must be a little different or there is an error in the Curtis key because I can get this thing all the way down and even and the fat part is into the crank a bit. ???

[Dangerous400EX]

You have the Curtis Sparks key and not another brand right?

The important thing is to have enough of the key sticking up to hold the flywheel in place. If you dont have that you should contact Sparks racing.

If it "sinks in" a thousandths or two that would not be a big deal, but too much and it could shear off and you would be stranded somewhere

[motox92]

great write up

[MAKO19]

Alright I went back out to the barn and tore it apart again. This time armed with Verniers, a depth micrometer, and torque wrench. I took the old key and the Sparks key and measured them with the Vernier calipers and they were dead nuts identical. I then installed the old key and checked the distance from the top of the key to the adjacent surface on the crank. Then I popped it out and installed the Sparks key and took another measurement. It was +/- 0.001" different from stock. I guess the thinner look of the sparks key makes it look like there is less key sticking out of the crank. Then (as directed) I put everything back together and torqued the flywheel bolt to 94 ft-lbs and she is up and running again.

Moral of the story, make sure the key is seated all the way in the key way and even.

We're supposed to get some good weather around here tomorrow so I can't wait to go raise a little hell in the woods after work and test this thing out!!

Thanks again for all the help guys.

[tri5ron]

good job,
I'm confident you'll be pleased, (and maybe even a little impressed), with the results.

make sure you sit/lean a little farther forward than usual, for your first launch.
If you've got good traction, the front end may be a bit 'lighter', and will probably stand up a little quicker than you are used to.

enjoy...

Originally posted by tri5ron
good job,
I'm confident you'll be pleased, (and maybe even a little impressed), with the results.

make sure you sit/lean a little farther forward than usual, for your first launch.
If you've got good traction, the front end may be a bit 'lighter', and will probably stand up a little quicker than you are used to.

enjoy...

Thats exactly what I did followng your instructions through the whole thing. You were spot on. I was sitting on the tank lifting it up

[tri5ron]

here's a little shot from last weekend.
keep a few things in mind while looking at the pic...

1- I am 180lbs, and sitting on the front tip of the seat, and a 85-90 lbs kid is sitting behind me. (approx. 265 lbs on the seat)

2- engine wise, it's dang near stock.
All it's got is, a big gun full exhaust, k&n, lid removed , jetted, and Sparks key.

Stock bore/compression piston, Stock cam, Stock carb, Stock rev limiter, Stock gearing.

We are on a hardpack dirt road, and Turf Tamer rear tires.

No double clutching, No leaning back, No yanking on the bars.
This is simply a 3rd gear, Roll-on power. No snapping the throttle.

Yeah, I like the Sparks key alot.

[Pabst_Powered]

great write up, this is what used...now for a quick ?. if you were to do this wrong would it still start and run fine, cause when i did this i didnt feel any change in the least, ran like it always did

Originally posted by Pabst_Powered
great write up, this is what used...now for a quick ?. if you were to do this wrong would it still start and run fine, cause when i did this i didnt feel any change in the least, ran like it always did

i'm guessing you didnt hold the flywheel to the side to advance it and its at stock timing

[Dangerous400EX]

Also if you were on the lean side before with your jetting, you would be even leaner now and probably would not see much of a difference