'91 KDX 250 Build thread, all advice, tips, criticism welcome

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TheGarBrah
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Re: '91 KDX 250 Build thread, all advice, tips, criticism welcome

Post by TheGarBrah »

PacificNWRider wrote: 10:10 am Jul 20 2020 Got the frame painted. Rebuilt the forks, stem bearings. Fixed the airbox, and fitted a newer KX fender, looks good I think.
What brand and color paint did you use for the green ? It looks kind of like Duplicolor engine enamel paint but that could be way off
PacificNWRider
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Re: '91 KDX 250 Build thread, all advice, tips, criticism welcome

Post by PacificNWRider »

I used Grabber Green, I checked a couple, it seemed to match the OEM plastics the best, whether it be from them being faded I am not sure, but I like the color.

Yes it was Duplicolor engine enamel. The ceramic stuff holds up well enough.. if you prep good. just touch up where you boots rub it, after a while. Never really saw the need to powder coat, yes, its far superior in quality, but I've never seen my frames get messed up except for by my boots, and powder coat doesn't stop that.. don't think its necessary really, unless you are restoring something rare or vintage..
'91 KDX 250 D1
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Re: '91 KDX 250 Build thread, all advice, tips, criticism welcome

Post by PacificNWRider »

Hard to show the beauty and smiles this brings. Take a look at the first pictures of the porosity in comparison to how it looks now. Wowza!

Amazing! :drool: There is a bunch of oil smeared on it also
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'91 KDX 250 D1
PacificNWRider
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Re: '91 KDX 250 Build thread, all advice, tips, criticism welcome

Post by PacificNWRider »

Bike is finished and running well enough so far, did a 15 minute "break in" last night. Not sure if the jetting is right. I believe it was rich. I mixed 32:1 and jetted at 38/158. I know the 32:1 is a bit rich, but I was concerned about running brand new and lean. Seems to run up ok, and once you get on the pipe it gets boggy at high RPM.

Doesn't want to idle too much, when adjusting idle screw don't get alot of adjustment, starts to hang idle.... seems rich to me

--- Should I run the bike out for a while yet before changing jetting?

Here's what I got so far

-New plating / New cylinder / New rings - Stock
-K 38 with 38/158 - CEL needle, 3rd slot
-Boyesen Reeds
-Pro Circuit pipe, FMF turbo Silencer
-A few holes in the top of airbox lid, nothing too crazy but some holes.
-UNI filter
-Maxima castor - 32:1
'91 KDX 250 D1
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Re: '91 KDX 250 Build thread, all advice, tips, criticism welcome

Post by KDXGarage »

Stock is 42/165. Why are you at 38/158?

https://www.partzilla.com/catalog/kawas ... carburetor

Cylinder looked great!
Thank you for participating on kdxrider.net. :bravo:
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Re: '91 KDX 250 Build thread, all advice, tips, criticism welcome

Post by PacificNWRider »

Cylinder still looks great!

I figured I would just throw some jets in a bag and have a my wife pick two from random..... :blink:

I put those jets in after reading multiple posts from you among others about the stock jetting being rich. I chose to start at a point where many had verified good results. I think it is mighty close like this, probably need a 155 main, and a 35 pilot.....

Besides my excuse, you are right. I have no business listening to random people.

I will jet it stock, and pretty much follow the tuning guidelines offered by Indawoods, that is pretty much how I tune all my carburetors, cept for the few dual, triple, quad carb setup's.

Many thanks for all the help, tips, advice, criticism! :bravo:
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Re: '91 KDX 250 Build thread, all advice, tips, criticism welcome

Post by PacificNWRider »

Forgot the lower radiator shroud bolt, after checking plug, doh..

Here's the glamour shots, will never look like this again.. :grin:

Image
Last edited by PacificNWRider on 03:23 pm Aug 04 2020, edited 6 times in total.
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Re: '91 KDX 250 Build thread, all advice, tips, criticism welcome

Post by PacificNWRider »

Image

:mrgreen: oops the last one just me workin on the fence, talking to neighbor.. :mrgreen:
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Re: '91 KDX 250 Build thread, all advice, tips, criticism welcome

Post by KDXGarage »

PacificNWRider wrote: 01:53 pm Jul 26 2020 Cylinder still looks great!

I figured I would just throw some jets in a bag and have a my wife pick two from random..... :blink:

I put those jets in after reading multiple posts from you among others about the stock jetting being rich. I chose to start at a point where many had verified good results. I think it is mighty close like this, probably need a 155 main, and a 35 pilot.....

Besides my excuse, you are right. I have no business listening to random people.

I will jet it stock, and pretty much follow the tuning guidelines offered by Indawoods, that is pretty much how I tune all my carburetors, cept for the few dual, triple, quad carb setup's.

Many thanks for all the help, tips, advice, criticism! :bravo:
I looked back through this thread. I didn't mention any jetting advice. If you can point me to some other thread where I commented on KDX250 jetting, please do. I would like to edit it, if need be. All I know is that many have commented that the stock slide is one number too rich. There aren't "many" on kdxrider that have a KDX250. There are a massive amount of jetting threads on the KDX200 and KDX220R. Is there a chance you read a KDX200 / KDX220R thread and used that information on your KDX250?
Thank you for participating on kdxrider.net. :bravo:
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PacificNWRider
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Re: '91 KDX 250 Build thread, all advice, tips, criticism welcome

Post by PacificNWRider »

I apologize, I probably did read a different forum member or name, I think I had you confused with another guy name is SS### something. There is alot of threads about kdx250 jetting though I think a good portion was from a couple other sites. probably read 500 threads trying to do as much research as I could, while rebuilding the bike, seemed problematic so I was trying to break the bike in at a more neutral point if that makes sense. (stock usually being that point, but not according to everyone on the forums)

Anyway, I changed the jetting, it's breaking in very nice, its a bit rich for sure, but the bike seems to love it and I have peace of mind that its not running lean.

Thank you for pointing me in the stock direction, not sure what I was thinking. I can deal with a muffler repack after I get some hours on the engine then possibly lean it up a bit. I only rode the bike around the yard for about 10-15 mins slowly before my post earlier so didn't run it too lean or hard, barely had her warm.

Bike starting to wake up feels like a monster, got about 20 more minutes on it today and it wants more :)

I had more pictures and write up to share but didn't see alot of interest as I realized what you are saying about most people have a 200/220

Thank again!
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Re: '91 KDX 250 Build thread, all advice, tips, criticism welcome

Post by bufftester »

I can't speak for others on here, but I like seeing the pics and details from bike builds. The KDX250 and 200/220 are very close but do have some unique details from each other. Share away, I can say with pretty high confidence that nobody on here has ever complained about sharing moto pics!
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Re: '91 KDX 250 Build thread, all advice, tips, criticism welcome

Post by KDXGarage »

Thanks for the update. Though disassembled for many years, I actually own a 1991 KDX250. It is definitely a fair bit different than the 200/220.

There are a good many here that read without replying. Keep up the good work.
Thank you for participating on kdxrider.net. :bravo:
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Re: '91 KDX 250 Build thread, all advice, tips, criticism welcome

Post by Vossman »

Great rebuild thread.
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Re: '91 KDX 250 Build thread, all advice, tips, criticism welcome

Post by PacificNWRider »

Not sure if the pictures are showing up, seems like they got DELETED from google or something . :kick:

Image
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Re: '91 KDX 250 Build thread, all advice, tips, criticism welcome

Post by PacificNWRider »

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Re: '91 KDX 250 Build thread, all advice, tips, criticism welcome

Post by KDXGarage »

no workie
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Re: '91 KDX 250 Build thread, all advice, tips, criticism welcome

Post by Pressingonward »

Nice build! Bike looks great!
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Re: '91 KDX 250 Build thread, all advice, tips, criticism welcome

Post by PacificNWRider »

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Re: '91 KDX 250 Build thread, all advice, tips, criticism welcome

Post by PacificNWRider »

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Re: '91 KDX 250 Build thread, all advice, tips, criticism welcome

Post by PacificNWRider »

Image

In this picture you can kinda tell the bike is flattened out a little more, I customized the seat and brackets to bring it lower on the bike. I modified the plastic base instead of the foam so the seat would remain original and comfortable? It sits about 1" lower in the rear, takes away some of the "banana" shape. With the KX fender it gives it a nice look, although the color is quite a bit different...

You think I should trim that little nub that sticks out on the number plate right above the exhaust, so it matches the fender??
I just hate to cut the original stuff....
Last edited by PacificNWRider on 04:39 pm Aug 04 2020, edited 2 times in total.
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