Timing a mid 90's kx500 for snowbike

5hunny

so ya found one huh, got a long track for it??

Cant wait to see this run, Garry

Hi,G-man.
The 500 is not hard to start........with a decompressor.
Retarding the timing a hair helps with starting also, and lets it rev out
a little freer. Adjusting the exhaust valve so they dont over rotate
helps also and is part of the cure to prevent kickbacks.
The correct pilot jet is important, too. Then it should start like a 125!
Have fun.

the gman said:

Yep, no long track, I like the shortie, running my 14 kit on it. If I can get it started....

Click to expand...

500 and a big track go together like peas and honey!

https://m.youtube.com/watch?v=49mhkRUPVjs

put as much timing in it as you can. stock isnt close to enough. more timing helps the power everywhere. just run good fuel. been playing a bit on dyno w mine.

i have a pvl ignition, and it supposedly has the same curve as the stock kx ignition. mine is set at 19 degrees offset from tdc. thats way beyond what they tell you to run.

mine has some work done to it, but going from 16 deg to 19deg there is a 20 horse difference. basically bumps up the whole power curve.

be sure to add some fuel though. with the same jetting at 16 degrees, everything was wet inside and egt's were way up as it was pretty much just burning 1/2 the fuel in the pipe. crank it to 19 and egt's come down, start seeing some carbon in the engine like it should be.

Hey, Portgrinder!
Hope your having a good summer. Dirt biking is hot and dusty here right now.
We need some rain!
Your timing results are interesting. One of our kx500 motors is a 550 Gorr motor with PVL ignition. Same as you, we kept giving it more and more
timing and it ran stronger with each advance.
Not so with stock ignition and stock port timing. Try that much advance on a stocker and it kicks like a mule and runs like a P.O.S.
Some people like the PVL ignition, but I kinda learned to hate it. No key on the crank is a nuisance. I find it easier to move the stator instead of the flywheel
for timing changes. With a key your TDC marks stay consistent,too. But at least you can get some lighting power with a PVL!
The highly modded motors are funny. Big dyno numbers look great and all, but for rideability, reliability and fuel mileage, its hard to beat a well built, well tuned, close to stock motor.
So in our experience, retarding the timing a hair ON A STOCK kx 500 helps starting and improves rideability.
Weird that we're thinking about this stuff in August, eh?

i hear you, but i'll take 80 over 60 any day. would be one thing if its peaky but its not. raised the whole curve in my case.