How to tell if new top end is needed...?

[drxr]

Brand new to the 2 stroke world as of yesterday... I just picked up a 2000 kdx 220 and the owner said he had never been in the engine... When I picked it up, it was needing some love. It cleaned up pretty nice. I changed the trans. oil, anitfreeze, lubed, etc. It seems to run really good and starts on the first kick... My question for you guys is.... How do you know when it needs a new top end? It appears to have been ridden quite a bit, but seems to run nicely... Thanks to you fellas and I enjoy the site!

Craig

 

[JasonWho]

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[Rhodester]

If you know what piston slap sounds like that would be a big indicator.

 

[rethnal]

Replace the piston first! (due to failure reports) Jet it correctly. If he has never been in the motor, it is probably jetted rich.
Buy a manual, read it, Every year do a compression check.... this is a good indications of condition. If you want a reference, Most KDX's can go several years without doing a top end. It just depends on how much riding you do. Usually if it starts easy (means good compression), runs good, has plenty of get up and go, you don't need a top end. Sure ...if you want to be anal about it as some are, you could do a topend every season... but it's not needed.
What kind of 2 stroke oil did the guy use? You will want to clean the kips when you replace the piston.

 

[drxr]

He always used the yamaha racing 2 stroke premix oil. From what I understand, this is a great oil so I plan on continuing to use it...

I need to do some homework regarding the kips systed. Don't even know what kips stands for or what it does...

I have an 04 450exc ktm so I am familiar to 4 strokes only. I just always wanted a kdx for a second bike. The 2 stroke power is definitely a different feel!

Thanks,
Craig

ps. how do you see past posts after they go off the first page?

 

[bentbars]

beware of the kdx rattle. sounds just like piston slap. this is a normal sound on a kdx.

 

[spctrbytz]

Rattle

beware of the kdx rattle. sounds just like piston slap. this is a normal sound on a kdx.

Agree - I bought a barely used 2002 KDX 200 the other day. I traveled a few hours to see it, and thought it was going to blow a piston as soon as I fired it up. Sounded like there was 1/4 inch of play in the wrist pin! The dealer caught the look in my eye and took me over to listen to two new KDXs, a 200 and 220 and let me listen to the engines on the other bikes.

Since the last KDX I owned was an '84, I never had heard the 'KDX Rattle' for myself. Needless to say, I am getting used to its unique tone and hopefully will be able to notice if something DOES get loose in there.

Inspection of the top end is the only way to know for sure, but these bikes seem to hold up better than most 4-strokes!

 

[rethnal]

KIPS = Kawasaki Intregrated PowerValve System! :)

 

[tax cutter]

ps. how do you see past posts after they go off the first page?

Bottom left of the forum page change your display options to show more threads.

 

[Bruce]

oh good... I can ignore my piston slap and assume it's kdx rattle... phew, another big job ignored... :)