KDXRIDER.NET

I've just bought a KDX220 and am having the top end done by the local mechanic. I'm in Thailand, where the KDX is rare, however the engine is similar to the locally made SuperKips 150, which is about the most common two stroke over here.

So I'm confident the mechanic is up to the job, but would like to know as much as possible myself to advise him.

I'd like to get the head milled to improve compression. The mechanic says he can do it, but questioned the need (I said it was a common mod for the 220, which he accepted).
Is there a standard measurement that should be milled? Somebody told me 1mm, but he felt this might be a bit much.
Is this all that's involved in the 'squish mod'?

no, milling and modding the squish are two different things. Although milling the head without modifying the squish would not be advisable.

this is kind of a silly doc...

http://www.muller.net/mullermachine/docs/squish1.html


but as you can see, milling surface material from the head will alter the existing squish band. At the very least it will need to be adjusted for proper clearance after milling, if not reconfigured completely.

RB is the man for the 220 head, if there's any chance you could get yours sent to him.

Sending the head to the US and back is not an option. Anymore details on why milling wouldn't be advisable? There seems to be a lot of mods for the KDX. I'm trying to find some that are accessible to me, there's no shortage of decent 2T mechanics around here, but the technical info seems to be lacking.

I'm not saying it's not advisable, and I understand completely about the issues with shipping to the US and back. I'd just want to make sure the guy knows what he's doing, that's all. It would kinda suck to get your head back, throw it on, and then promptly destroy the engine with the piston crown contacts the head. If your friend has experience, I'm sure he can figure out something that will work for you better than the stock configuration does. Right? One would hope.

He has about 25 years experience as a mechanic, mostly with 2 strokes and many of them racing bikes. He advised against the milling because it was a dirt bike. It may also have been because over here a 220 is considered a big engine, so he didn't think mods were necessary.

When I mentioned that the 220 is known for low compression, he said it may be worthwhile. I'm confident he could figure out something better than the stock configuration, although it would be great if I could provide with details of what has been done by others.

Well... it is hard for us to recommend anything but having Ron do it...

It's not like every guy down the block can do it right.... We trust 1 guy to do it in all the US!

You might shoot ron a line and tell him your situation, see if he can offer any advice without giving up any trade secrets.

I think I will leave the squish for the time being, the mod I'm really interested in is the RB carb, I will keep an eye out for a used one and maybe have it sent to him.

The cost of shipping is bad enough, then there are often customs taxes and the chance of something getting lost. A decent mechanic here is about $25 a day, the one I'm using is 500 yards down the road.

if the guy knows his stuff, I'm sure he can rework your head into something better. It's a weak point for the 220 for sure, as is the small carb. You're headed in the right direction I think.