90 kx 500

[Rougedante]

Does anyone know where to get a bottom end for these bikes. I have the chance to get one and id really like to have it but cant find aftermarker crank only oem...and its like 600bucks. Kinda crazy. Am I missing something. Also how often do you have to rebuild them new to kx. Thank you in advance

[reklessj]

Welcome to the site! Fun is never cheap!! Personally I think OEM Cranks are the way to go. Kawasaki makes a d**n tuff crank spend a few more bucks get it balanced and you wwon't be ddisappointed. I have a 94 And just got its first top to bottom freshening up and the whole bottom end and tranny was all in spec! All new bearings and sealsand piston and rings and she was all good. With good routine mmaintenance kx500 are very dependable!! Now go get it and post some pics

[sandblaster]

I would rebuild the crank with a Wossner rod kit, have it welded, balanced, and trued.
Cheaper then OEM and really tough...

[Rougedante]

Yea I know it aint cheap ive got a 00cr250 I just rebuilt ground up (engine wise) last winter. I want the bike for a mini buggy ive got. Kinroad 250...its my uncle but he hasnt ridden in over a year. Prob pull the engine and sell the rest of the bike...
As for rebuilding the crank how do I do tht. And do I have it rebuilt and then welded and trued? Also Would I just need complete bearing and seals kit and get the rod to complete the bottom end?  I just dont want to buy the engine just to not be able to afford to rebuild it when needed.  How long do these engines last. Somone told me they blow through cranks because the bore is too big...any opinions advice facts are welcome. Thank you guys

[Foxx4Beaver]

I would rebuild the crank with a Wossner rod kit, have it welded, balanced, and trued.
Cheaper then OEM and really tough...

my next motor/build is gonna be with a Wossner rod kit.

Also how often do you have to rebuild them new to kx. Thank you in advance

Welcome to the site Rougedante....
providing you keep on top of your general maintenance and always run quality 2 stroke oil, you should get a few years between rebuilds with ease. One of the old gurus on here claims he got 11 years out his original  motor before taking it apart for the 1st time.

"EDIT"...I was wrong...it was 12 years...
http://www.kxriders.com/forums/index.php/topic,1530.0.html

http://www.kxriders.com/forums/index.php/topic,1347.0.html

[Rougedante]

I run klotzr50 in my cr250 is that good stuff. And i
The motor would be in a little buggy maybe 800lbs tops including the engine. Would tht kill it faster or anything. I dont want to buy the bike and have to constantly rebuild the motor once its in and spend crazy amounts of money on rebuilding it. If I did a wossner rod and all tht how much do you think id be looking at for parts for bottom end only?

[Foxx4Beaver]

I've never used Klotz, so I don't know if it's good or bad.
providing you won't have to replace any tranny parts, you'll probably be around $800-$1K to rebuild the bottom.
On how often you'll need to rebuild it, it all depends on how hard you run it....and as I stated earlier, keep on top of your maintenance..i.e....keep a clean air filter on it always, and change the oil a lot!

have a look at this thread...is this anything similar to what you're thinking of doing?

http://www.kxriders.com/forums/index.php/topic,12529.0.html

[Rougedante]

Dang thats a pretty penny to rebuild the bottom end. I always clean my air filter and oil so no worries on that end. Umm ehhh on tht thread this is more what I want to put it in. http://m.youtube.com/watch?v=FFQo8vWm5I8

[Foxx4Beaver]

if you just replace the bearings and seals, you could do it for 1/2 that price...I tend to replace as much as I can, or need to.
800lbs, that thing weighs that much??...
the 500 motor should be able to push that thing around...won't really know how well until you try it.

[Rougedante]

It says 800 but I dont believe it. I can pick it up so im assuming 500lbs total. Its got a tiny 250cc honda clone nd it goes up to 40 but real slow no real power to it. So if I replaced seals bearings and rod assuming the cranks good prob 400-500? You think

[Foxx4Beaver]

yeah that should be about right...
how do you plan on cooling it?...not sure how much you've snooped around on here, but these motors run hot!...so be sure you come up with a good plan if you're gonna be running it in the dunes WOT a lot.

you might benefit from reading this thread over a bit...

http://www.kxriders.com/forums/index.php/topic,11480.0.html

[Rougedante]

Thats alot of reading lol. Busy right now so ill deff read it later but I figured run a car radiator up top like the buggy has now so the air blows thru it by itself and also get a electric fan off summit and put it on their. Should provide enough cooling power...and if not get a bigger radiator or run two tht  form a v facing the front with two big cc fans on them...

[Foxx4Beaver]

yeah it is a lot to read at once...
sounds like you've got a pretty good grasp on it though...

[Rougedante]

I went through 3 years of auto tech at our local highschool. We actually have the best program in northern nv. Rebuilt engine and trannies my senior year so I do have a basic idea how engines work lol and how to rig them to work in toys haha. Just need to find the right one thts worth it....

[Foxx4Beaver]

cool....post plenty of pics when you get things rolling.