89 KDX200 rebuild - KIPS parts missing recommendations and reasoning?

[kyferez]

I recently picked up a '89 KDX200 with seized bottom end. It needs a lot of work... That's ok, I got it for $100.

I have the bottom end split. Needs new piston, cylinder weld and replate, bearings, and crank bearing.

So none of that worries me. This is my first 2-stroke I'm working on that has a power-valve. The KIPS is missing several parts. I'm trying to find all the missing parts and understand options. I have found replacements, but they are $230, so would prefer other options...

Pics attached of what I have, and diagram with circled items are what is missing/damaged.

Few questions:

1. Why would someone have done what is pictured cutting off the gears and removing some of the parts? Edit I am assuming the were cut since the idle spur gear is also missing, but perhaps they broke and so someone removed the idle spur gear and collar valves and other missing parts.

2. What would you guys recommend here? Should I make it like factory, keep as is, or mod it somehow?

[Molly's 70]

It looks like the gears broke off. That doesn't look like they were cut off to me. Maybe it's the picture?

[KDXGarage]

Welcome to kdxrider.net.

I think they broke. I think that most of the time, people let them get built up with carbon, which leads to damage. Sorry that someone ran it in the ground so hard.

BDK Engineering makes some of the KIPS parts. Look on their site.

[kyferez]

Well if they broke, someone must have just removed the spur idle gear and other missing parts.

Is it not ok to run wide without the KIPS parts, just leaving it wide open? What would be the harm? Would power be sacrificed?

BDK is who has them on ebay for $230 :/ Pricy! BUT they are steel!

[KDXGarage]

Yes. Someone removed parts.

It will not make as much power, or deliver it in the same way. I don't know if it is harmful.

$180.87 at today's exchange rate on their website. eBay wants a 10% cut. One can even get charged state tax in some states for something that isn't even made or sold in this country or any state.

[kyferez]

$216 counting VAT. $234 after shipping. I'll see how it runs without before spending that extra.

Edit: Found some good info about powervalves here: http://dirtrider.net/forums3/threads/ru ... lve.22425/
Basically keeping it wide open decreases low end torque. Keeping it closed prevents top end torque. But, those at that link had a center plate. This 89 KDX200 doesn't - the main exhaust port stays open all the time, so I expect less difference with this older model.

Thanks!

[KDXGarage]

VAT! JOY!

Good luck.

[bigdhusker]

Fredette Racing also has the OEM replacements for the powervalve system