KDXRIDER.NET

Hello, new member here and I bought a new to me 97KDX220 that my buddy ran with stright gas until it welded rings to the piston and scored the cylinder wall.
Took the jug to a pro race engine builder (V8's) and he said it needs to be bored but dosent have tools small enough
So I ordered the .040 over weisco piston kit now im reading about re-sleeving, re-plating.
i need a straight answer before I go to the machine shop please?
if I bore to 70mm and chamfer ports, then do i find somewhere to replate? is there an extra tolerance needed for plating? what plating is it?
what are my other options to get her going?
New sleeve and stock bore piston?
Bore and chamfer what I have and dont plate?
im mechanically inclined but not much machine shop experience
Thank you for all your time

i understand the performance triangle of fast,cheap and reliable
im in the cheap and reliable sector, want to get some seat time in before i go to crazy

Stock was plated. With the 220 KIPS you can get to 70mm with not too much problem, but you may need to rework the main valve a bit. Regardless, even if you bore you need to replate. Best bet to contact one of the plating companies (Millenium is my preferred) and see what they can do for you.

Contact a plating company. Big mistake equals big expense.

Yeah, no bore. A good plating shop will weld up any damage to the aluminum cylinder itself, and then replate it. It will come back better than new, but it won't be cheap. If you bore it sans the replate, it has to be sleeved. Don't do that if you have any other option. Millennium is a good company. I'm a personal fan of langcourt. Seems over the last few years you need to avoid US Chrome.

Langcourt DOES NOT plate in the USA anymore.

After reading it again, I concur with Julien D, it probably can be welded / repaired, then plated. That is going to be your best option. Another option I have read others having great service with is Power Seal USA.

http://www.powersealusa.com/

Read this to get a better idea of what us numbskulls are trying to explain.

Anyway, in most cases like this, the best option in my opinion is to have it repaired and replated. It really will be better than new.

Also, I am concerned about the state of the bearing on the big end of the connecting rod as well as the two main bearings. The two - stroke oil lubricates these bearings. If it got hot enough to melt the piston, then I suggest ALL bearings are suspect. Also, I would check the crankshaft for "getting too hot", bluing, etc.

Thank y'all so much for the replies!
I'll call a plating company today
Another debate question,
If I'm doing all this work, why not bore it to 70 as apposed to fixing 69?
I like extra power, are there reliability issue? Overhearing?
What are the pros of staying stock bore?
Or do I have to go with a new sleeve at 70mm?
I'll take pics of damage in daylight
I think it could stay at 69 with a fresh replate... Maybe just cheaper to stay stock?

[img][IMG]http://i1100.photobucket.com/albums/g405/iamrobed/IMG_20170902_064000_zpsv63r4w3h.jpg[/img][/img]

Jason wrote:Langcourt DOES NOT plate in the USA anymore.

Really?? I just had one done by them a few years ago and was very happy. That's a shame!

The difference is displacement between 69 and 70 is 6cc (217 vs 223). You're not going to notice that small a change. You'd have more impact losing 10 pounds of riding weight. IMO the change is not worth the cost. The pros of staying stock are cost and availability of parts for a bike that has been out of production for 10 years now. If more power is a necessity, then you're better off stepping up to a 250/300.