Engine cases question

[red_eye_righley]

Hi Guys, hope all is well. Have been popping around and reading the threads but have been a little quieter with the posts lately - been really busy!

Having very little experience with building engines I was wondering if you could help me with some input. I have found a bike being scrapped as one of the engine cases is cracked, but I want the engine
So....
Could I buy the engine and a) replace the cracked case
b) replace both cases as I need a matching set
c) dont bother and rather wait for another buy (baring in mind that guys do not regularly part bikes out here in South Africa, unfortunately).

Thanks for any help or advice!

[Colorado Mike]

I have experience with looking for new cases. A KX-85 was going to cost about $400 Amurrikin munny. The YZ125 was an astounding $720. Which might be why many bikes that get their cases broken end up being parted out. Buying a motor that already has broken cases seems a little like buying used condoms to me, unless you're interested in what's inside. Hmm, that didn't come out right .... but in a way it did.

[red_eye_righley]

Yes, point taken. But I see quite a few engine cases for sale on fleabay from time to time, so was wondering if it may be worthwhile. That said, I think I may just buy an old KDX and part it out from there, obviously keeping the engine.
Cheers!

[red_eye_righley]

Hi Guys,
Sorry to harp on but.....I have found 1/2 an engine case set for a good price, if I used it to build a motor it would end up alot chaper than buying and breaking a bike for the engine - am I still barking up the wrong tree here?

[pietman]

Hi righley

What's your budget? Like I said on your other thread a while back you should look on http://www.junkmail.co.za . I've seen complete E model KDXs for around R6000 on there. There was a complete 1995 (H) KDX200 with "rebuilt engine" on there a week ago for R8000. I also saw a 2000 KDX200 engine on junkmail for R4000, but that was months ago.

Just keep an eye on junkmail and you'll eventually find a motor or a cheap bike that you can take the motor from.

[canyncarvr]

Re: 'I have found 1/2 an engine case set...'

Meaning either the left or right case?

It would be a lot easier if it's the left case you need. It comes off, leaving the crank/trans in place in the right case.

I've not done it myself...but I'd be happier with cases that came as a pair..had been matched. They cast lots of thousands of these things, and it isn't unreasonable to think that any two halves should fit together.

Still...I'd rather have a pair that had been bonded successfully at least once.

If you can only GET one side, I'd sure give it a shot.

Good luck!

[kawagumby]

I second trying the half-case....japanese manufacturing tolerances are so close that they do usually match up just fine - based on my one-time experience.

[red_eye_righley]

Ok, firstly - thanks for the GREAT replies to my asking, and re-asking the same question again!!!!!

Now for the replies:

Pietman: Budget=as cheap as I can go (I see KDX's for around 8k, and KX125's in good nick for around 18-20k - guys, we arent talking dollars here, dont worry ). The end result must just be nice - I can do all the "trick bits later" (first on the list is the 18" rear wheel). Thanks again for the advice, although everyone really likes the older KDX engine I am concerned about spares (but am getting over my fears and think I will go that route anyway). Most of the guys on JM advertise a '94 or whatever model and when I see a photo its an aircooled bike , but will keep looking thanks! Also, I am in Udeben - so all the vaal bikes are to far to look at unfortunately. But please Piet, if you find a bike taht looks good for these purposes please keep me in mind . I need to do some more reading on fitting the older motor to the new KX frame....mmm...

Canyncarvr and kawagumby - thanks a heap, sounds like it might be worth the risk and trying it out. I still need to go look at the case/cases that are cracked and see what the diagnosis is - but now you guys have me a little more positive about fitting a new case/cases to the rest....

[canyncarvr]

I don't see anything written about the crack.

WHAT crack?

Is this one'a those '..leaking under the flywheel' problems that some older US bikes have? Is it a crack caused by impact force (piston skirt shattered, rod broke) or maybe a blind bolt hole that was overtorqued?

Some cracks may be addressed with something like JBWeld or some other kind of epoxy/putty.

..and I'd still like to know WHICH side it is you're after.