Exhaust port uneven wear. Salvageable?

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Myersprostatus
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Exhaust port uneven wear. Salvageable?

Post by Myersprostatus »

Hello, I recently picked up a 86 kdx200 for a great deal. The bike ran, just not that great. I plan on bringing this bike back to life and outfitting itwith some more modern emenities. Upon tear down of the kdx I noticed it had a broken exhaust dampener bracket. It is the one located on the expansion chamber. The exhaust would move freely and there was plenty of carbon and oil where the exhaust pipe meets the exhaust port. I removed the engine and disassembled the top end. When cleaning the cylinder I noticed the copper washer had actually some what embedded itself into the interior of the exhaust port. I managed to remove it completely, but once all the soot and carbon was cleaned I found that the walls of the exhaust port have deep grooves burred into its walls. Is this salvageable? Or is a new cylinder required? I understand New o-rings woukd aid in filling space, as well as some high temp rtv, but these grooves are fairly deep and I don’t know if I will get a complete seal for the exhaust. Any info/advice is welcome and appreciated. Here are some pics of the damage.
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KDXGarage
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Re: Exhaust port uneven wear. Salvageable?

Post by KDXGarage »

Welcome to kdxrider. Thanks for joining us.

Someone let the steel pipe fight against the aluminum cylinder for far too long. That is why it is damaged.

Are you looking for the cheapest way or the best way? A few options are:

Run as it is. Put the silicone sealant on thick and replace often.

all the way to...

Possibly pay someone to TIG weld more aluminum into the exhaust pipe mount area, then machine it down

Somewhere in the middle is JB Weld, metal shims, etc. to take up the room of the missing metal.

Thanks again for joining, and thanks for cleaning the area you are wanting us to look at.

You may want to look on eBay for an "Owner's Manual & Service Manual" from Kawasaki if you don't already have one. I guarantee you that it will be the best money you spend on the bike.
Thank you for participating on kdxrider.net. :bravo:
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Myersprostatus
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Re: Exhaust port uneven wear. Salvageable?

Post by Myersprostatus »

I agree. Can’t believe they let the exhaust move freely like that. Kinda sucks, cause I have great plans for it. Don’t know if I wanna dump much money into this engine that is not guaranteed to seal.
Thank you for the warm greetings though, appreciate it. I’m purchasing a manual as soon as I get paid. I may just go the silicon route. Guess I’ll wait and see.
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Re: Exhaust port uneven wear. Salvageable?

Post by KDXGarage »

Depending on how much material has been removed, do you think it would be possible to put a very thin shim inside it? I know I hae purchased 0.025" thick material before. Perhaps a sealant to hold it in place (besides the ton of silicone) :grin:
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bufftester
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Re: Exhaust port uneven wear. Salvageable?

Post by bufftester »

Welcome to the site.

Another option along the JB weld path would be to wrap the end of the pipe with a layer of duct tape or silicon tape to give you the correct diameter, set it in the exhaust port in the correct position and then use JB weld to build up between the pipe and the head. Let it cure, install o-ring and hi temp sealant and ride it. Cheaper than welding/machining (best option imo but pricey) and may give you a better seal than just slathering on hi temp in the present condition.
Myersprostatus
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Re: Exhaust port uneven wear. Salvageable?

Post by Myersprostatus »

Thanks for the advice guys I may be able to fit a shim. I’m gonna order some new o-rings and see how the exhaust fits. I may have to throw some jb weld in there as well, as the it would make for an even surface. I’ll know soon enough
pkenney
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Re: Exhaust port uneven wear. Salvageable?

Post by pkenney »

Mine looks about the same and with fresh O-rings it does not leak.
The 45mm O-ring OD is quite a bit bigger than the pipe OD so it takes up a pretty big gap.
BTW, there is a copper ring at the head/pipe joint that is about $15.
Mine never had this and I didn't know about it until I looked for replacement O-rings and saw it on the diagram.
it looks like a piece of 12 or 14ga solid copper wire would do the trick too but I don't know how it would hold up.
ScruffyDroid
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Re: Exhaust port uneven wear. Salvageable?

Post by ScruffyDroid »

You need these

https://www.motorcycleproducts.co.uk/ex ... 98579.html

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pkenney
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Exhaust port uneven wear. Salvageable?

Post by pkenney »

I'm not sure that copper O-Ring would fit since the OD is 46mm but if the hole is already oversize it might be good.
I ordered the OEM P/N 11060-1437 from Rocky Mountain and the copper was only about 1mm thick.
Are the later years meant to crush to seal the pipe?
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