Maintenance & Technical > KX500 Original
Stock vs. aftermarket piston and engine balancing.
gil2264:
I just joined the KX500 club about a month ago. I had the head off a week ago, and it seems like there is a lot of slop between the piston and cylinder. I think it will be ok for a little while, but I'm going to change out the piston this winter. I was just wondering if the weight difference between a stock (OEM) piston, and an aftermarket, ex.(Weisco Pro-lite) makes much difference in the amount vibration from the engine. It would seem to make sense to me that the crank and lobes would be balanced for the stock piston, but a lighter or heavier piston would throw the whole works off balance and cause increased vibration. :-o
I'm also planning on having the cylinder replated at Luke?s Racing (http://www.lukesracing.com/luksr/np.html). He's only about 50 miles from me so I can go up there myself to check out the shop. Any opinions about his work would be appreciated.
I have some other mods I plan on making this winter also, including: Setting up the suspension, adding a flywheel weight, lighting coil, headlight, taillight, Spark arrestor...basically I'm trying to make a large KDX out of it for high altitude mountain riding. (8,000'-13,800') and I weigh 300 lbs.
Any advice for building to this purpose would also be appreciated. :-D
Thanks
Dan Gillman
Gil2264@earthlink.net
GDubb:
I cant help you with much, but I can tell you that its pretty unanimous around here that lukes racing is the way to go. I havent read anything but good things about them and there is quite a few first handers around here that vouch for the quality of their services and customer care.
Polar-Bus:
--- Quote from: gil2264 on November 23, 2006, 01:35:12 PM --- I just joined the KX500 club about a month ago. I had the head off a week ago, and it seems like there is a lot of slop between the piston and cylinder. I think it will be ok for a little while, but I'm going to change out the piston this winter. I was just wondering if the weight difference between a stock (OEM) piston, and an aftermarket, ex.(Weisco Pro-lite) makes much difference in the amount vibration from the engine. It would seem to make sense to me that the crank and lobes would be balanced for the stock piston, but a lighter or heavier piston would throw the whole works off balance and cause increased vibration. :-o
I'm also planning on having the cylinder replated at Luke?s Racing (http://www.lukesracing.com/luksr/np.html). He's only about 50 miles from me so I can go up there myself to check out the shop. Any opinions about his work would be appreciated.
I have some other mods I plan on making this winter also, including: Setting up the suspension, adding a flywheel weight, lighting coil, headlight, taillight, Spark arrestor...basically I'm trying to make a large KDX out of it for high altitude mountain riding. (8,000'-13,800') and I weigh 300 lbs.
Any advice for building to this purpose would also be appreciated. :-D
Thanks
Dan Gillman
Gil2264@earthlink.net
--- End quote ---
Stock OE Kawasaki pistons are cast. Wiseco's are forged. Cast pistons have minimal expansion, so the tolerences are tight. Forged pistons expand much more than cast ones, so the clearences need to be set up looser. Forged pistons claim to be stronger, but forged pistons as a result of the looseer clearences, "knock" when the engine is warming up. Cast pistons are generally more reliable to run. I ran one Wiseco years ago, and siezed it up after only 3 races. Not 100% sure if it was the pistons fault (as it was a fresh re-sleeve job). I've changed about 25 top ends usingthe stock OEM Kawi pistons with only one OE piston failure.
gil2264:
I take it, that means warm up is even more critical with a forged piston. Any favorite warm up proceedures? for trhe kx5 seeing as it doesn;t like to idle?
gowen:
I have used Wiseco since I started dirtbiking as a kid. Very reliable. No balancing issues at all. The warm up is critical, but should be taken easy on ANY 2 strokes. peroid.
I used to have a 250r that I gave to my cousin. It siezed a Wiseco and thought I would try going back to stock instead of Wiseco, due to the fact that it siezed.. Instead of siezing and causing minor damage, the stock OEM piston collapsed and ruined the entire motor. I never foudn why it kept locking up.. Don't care anymore. But found that Wiseco has never collapsed ever and I've seen multiple OEM and Pro-X pistons collapse. I've rebuild 20+ two strokes in the past few years. I'm still on a 100+ hour piston in my YZ250... No issues and just inspected it not long ago (Wiseco).
Take it with a grain of salt.. It's personal preference. Just like Aluminum (crap)sprockets and reed spacers (cra...*censored* :-) )
Navigation
[0] Message Index
[#] Next page
Go to full version