Author Topic: top end (Read 3643 times)

gwcrim · « **on:** December 12, 2003, 03:16:46 AM »

Just sold a pile of parts and can now rationalize plating the jug and getting a new piston.

As for the head, should I have it cut to reduce pinging? I never had a problem with it before but then my compression certainly wasn't at the high end of the scale.

Do these things usually ping under normal circumstances on pump gas? (I refuse to have a vehicle that needs more than pump swill.)

doordie · « **Reply #1 on:** December 14, 2003, 04:17:28 AM »

qwcrim!
Measure the squish clearance ,should be between 1,3mm and 1,5mm,(important not below 1,3mm)otherotherwise it will "pinging" under heavy load.Measure and calculate the compression so it`s not to high for the gas you run.

Rick · « **Reply #2 on:** December 15, 2003, 11:54:05 AM »

Where are you located? Remember, higher elevations don't require as high octane fuel as those in lower elevations. In Idaho, I run 92 Octane Chevron. When I go to California to race, it's VP Red all the way.

Rick

gwcrim · « **Reply #3 on:** December 16, 2003, 02:46:24 AM »

I'm in Ohio @ 1100'.

I talked to Eric Gorr yesterday and explained my situation as merely a woods rider. He recommended lowering the compression. He does the replate, supplies the piston assy, gaskets, and cleans up the ports and KIPS valve for $400. Not a bad deal. Might call B&B as well.

doordie · « **Reply #4 on:** December 16, 2003, 05:44:10 AM »

qwcrim!
You can do this by yourself and save money

A stock kx500 can have a piston too "short" and a barell too "long" when they fabricate the engine.
This make your squish-clearance way to far, if you are unlucky to have this "sort" of engine, you have some problem!
It will detonate under heavy load.

But if you reduce the clearance, the endgases on top of piston when it?s have been fired from sparkplug will not detonate and cause the pinging.
You can ask any tuner(E.G) if you don?t belive me.
It?s will cost you time and not money if you do this by yourself , maybe only buy a thinner headgasket!
But make sure not go less then 1,3mm!
(piston/headbanging).
Sorry about my bad english then

gwcrim · « **Reply #5 on:** December 16, 2003, 05:51:49 AM »

I do have some top end experience and I understand setting up squish. It would cost me $300 just for a piston and a replate. For the added $100 Gorr does some minor port cleaning and cleans and sets up the KIPS valve. Oh that includes a $40 gasket set. All in all, a decent deal.

doordie · « **Reply #6 on:** December 16, 2003, 08:56:29 AM »