KX Riders

Maintenance & Technical => KX500 Original => Topic started by: Hillger on March 21, 2014, 12:57:39 PM

Title: Engine compression
Post by: Hillger on March 21, 2014, 12:57:39 PM
I have an 89 kx500 the bike has compression, I know I need to test it but I am unsure of what the compression it is suppose to be and if there are any tips anyone can give me on the best way of  testing it?
Title: Re: Engine compression
Post by: sandblaster on March 21, 2014, 02:29:04 PM
Compression gauge.
Unscrew the spark plug, screw in the gauge, open the throttle wide open, (Make sure your air filter is clean) and kick it like you want to really ride it bad.
Tell us where it is at  :-D
Title: Re: Engine compression
Post by: Hillger on March 21, 2014, 02:35:26 PM
Well Alrighty sounds easy enough thanks for the input and I'll let you know sometime tomorrow
Title: Re: Engine compression
Post by: Hillger on March 23, 2014, 12:32:16 PM
Well I have gotten the compression keep in mind it was on a cold engine considering I need a carb to get the engine warm the psi was 30 I have a bad feeling I need to do a top end:/
Title: Re: Engine compression
Post by: Foxx4Beaver on March 23, 2014, 12:36:56 PM
the book says the useable range is 105psi-164psi....but that's on a fully warmed up motor...I'm willing to bet you'll know if it needs a top-end the second you pull the head/cylinder :wink:

keep in mind that's based on a stock engine.
Title: Re: Engine compression
Post by: Hillger on March 23, 2014, 12:41:55 PM
I pulled the head not the cylinder I  kicked the engine with my had was difficult so I know there's  compression I looked over the cylinder didn't see any scoring but I am also not a professional by any means in learning as I go.
Title: Re: Engine compression
Post by: Foxx4Beaver on March 23, 2014, 12:46:22 PM
post some pics of the cylinder plating, showing the intake and exhaust sides if ya can...pics are always good.
Title: Re: Engine compression
Post by: Hillger on March 23, 2014, 01:27:00 PM
Okay I will do that tomorrow
Title: Re: Engine compression
Post by: Hillger on March 23, 2014, 01:30:55 PM
The exhaust side typically looks a bit more worn right??
Title: Re: Engine compression
Post by: sandblaster on March 23, 2014, 01:36:11 PM
Yep.. Typically.... but not always   :wink:
Title: Re: Engine compression
Post by: Foxx4Beaver on March 23, 2014, 01:36:28 PM
not necessarily...ever seen the inside of a cylinder where the owner never cleaned the filter?? :-o

are you seeing something to make you ask that question?
Title: Re: Engine compression
Post by: Hillger on March 23, 2014, 01:39:19 PM
No sir just curios just things I've heard from others wanted to verify if it was true or not.