1991 KX250 project

kelroy_leon
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kelroy_leon
Edited Date/Time 12/12/2020 6:21am
Hello,
I have a line on a honest use but solid '91 KX250. My only other KX is my '94 500 project. Are there any issues that I should look out for that may be a common problem? Any info is appreciated. The bike seems rather low use, mostly original. Other than common wear and tear parts and the silencer.
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sandman768
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sandman768 5/23/2015 2:00pm
5/23/2015 2:00pm
kelroy_leon wrote:
Hello, I have a line on a honest use but solid '91 KX250. My only other KX is my '94 500 project. Are there any issues...
Hello,
I have a line on a honest use but solid '91 KX250. My only other KX is my '94 500 project. Are there any issues that I should look out for that may be a common problem? Any info is appreciated. The bike seems rather low use, mostly original. Other than common wear and tear parts and the silencer.
i had 89, 90 & 91 kx 250"s back when I was chasing b class points. the 91 was a decent bike, the 90 had a much harder "hit" for 91 kawie went back to the 89"s mellow power deivery. I only kept my bikes for 1 season back then but, here is what I remember: perimeter frame made bike feel tall, not a great turning bike but, very stable in the rough. foot peg springs donot last long, airbox would leak if not sealed with rtv at boot to box junction, I think all the 90"s bikes leaked air there! nut certs would push out or strip out of subframe, linkage bolts need to be loctited to frame. front brake always felt spongy, even after bleeding. I always had to add a splsh of race gas to keep detonation to minimum, plating on cylinders had issues on some bikes, could have been from the detonating. I never blew one up, but upon teardown the plating was starting to chip off. could have been my lack of jetting skills back then. kips valves in cylinder gum up quickly, ..all 3 of my kx"s treated me well. I rode a friends 89 cr 250 & never bought another kx....it was faster & turned better than all my kx"s...
MXtoXS
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MXtoXS 5/25/2015 6:47pm
5/25/2015 6:47pm
Crappy footpegs/mounts, soft frame material, funky aluminum shock mount. Look for cracks near welds. Yes they were big and boaty...good for rough mx tracks, but not for changing direction quickly.
Kidkawie
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Kidkawie 5/26/2015 11:07am
5/26/2015 11:07am
Powervalve parts can be a bitch to find. Post some pics if you buy it.

The Shop

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BM255
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BM255 5/27/2015 1:15am
5/27/2015 1:15am Edited Date/Time 5/27/2015 1:19am
MXtoXS wrote:
Crappy footpegs/mounts, soft frame material, funky aluminum shock mount. Look for cracks near welds. Yes they were big and boaty...good for rough mx tracks, but not...
Crappy footpegs/mounts, soft frame material, funky aluminum shock mount. Look for cracks near welds. Yes they were big and boaty...good for rough mx tracks, but not for changing direction quickly.
x 2 on the frame

This is the frame on my 90 kx250 I'm restoring, you can see where someone has attempted to repair it in a number of places, luckily I sourced another frame with no issues which I'll use for my build, this one however is no good for anything











Kidkawie
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Kidkawie 5/27/2015 5:43am
5/27/2015 5:43am
I had to do repairs to my 94 frame. Cracks on the lower cradle and a missing subframe tab. I vee'd out the cracks, welded and blended. But it's pretty common for those early 90's bikes to have cracked frames. Not sure exactly what year they changed things.
kelroy_leon
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kelroy_leon 5/27/2015 11:44am
5/27/2015 11:44am
This question is a bit off topic but, what is the difference between '91 KX125 and 250 shrouds?
BM255
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BM255 5/28/2015 1:17am
5/28/2015 1:17am
kelroy_leon wrote:
This question is a bit off topic but, what is the difference between '91 KX125 and 250 shrouds?
I think they are the same, Kidkawie will know for sure though.
Kidkawie
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Kidkawie 5/28/2015 7:13am
5/28/2015 7:13am
I have no idea. Tank and LH shroud are the same part numbers. RH shroud numbers are different. Maybe a notch or something for the pipe?
Banana_oil
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Banana_oil 5/28/2015 10:39am
5/28/2015 10:39am
The 125 right shroud has a bit higher lwer edge to not interfere with the pipe
kelroy_leon
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kelroy_leon 5/28/2015 4:51pm
5/28/2015 4:51pm
My modern technology is not cooperating at the moment so pictures will have to wait.

I wish I could track down the plastics to make it look like this.... I see the front fender and shrouds on E-bay currently.
Jeremy200
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Jeremy200 5/29/2015 3:43am
5/29/2015 3:43am
MXtoXS wrote:
Crappy footpegs/mounts, soft frame material, funky aluminum shock mount. Look for cracks near welds. Yes they were big and boaty...good for rough mx tracks, but not...
Crappy footpegs/mounts, soft frame material, funky aluminum shock mount. Look for cracks near welds. Yes they were big and boaty...good for rough mx tracks, but not for changing direction quickly.
BM255 wrote:
x 2 on the frame This is the frame on my 90 kx250 I'm restoring, you can see where someone has attempted to repair it in...
x 2 on the frame

This is the frame on my 90 kx250 I'm restoring, you can see where someone has attempted to repair it in a number of places, luckily I sourced another frame with no issues which I'll use for my build, this one however is no good for anything











shit, that must have been a shock.

did you get the newer frame locally?

have you started the build yet?
BM255
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BM255 5/31/2015 2:57am
5/31/2015 2:57am
MXtoXS wrote:
Crappy footpegs/mounts, soft frame material, funky aluminum shock mount. Look for cracks near welds. Yes they were big and boaty...good for rough mx tracks, but not...
Crappy footpegs/mounts, soft frame material, funky aluminum shock mount. Look for cracks near welds. Yes they were big and boaty...good for rough mx tracks, but not for changing direction quickly.
BM255 wrote:
x 2 on the frame This is the frame on my 90 kx250 I'm restoring, you can see where someone has attempted to repair it in...
x 2 on the frame

This is the frame on my 90 kx250 I'm restoring, you can see where someone has attempted to repair it in a number of places, luckily I sourced another frame with no issues which I'll use for my build, this one however is no good for anything











Jeremy200 wrote:
shit, that must have been a shock.

did you get the newer frame locally?

have you started the build yet?
I knew it had been welded up in one part but I was surprised it was so bad everywhere else, got the other frame from Hawera along with a spare fuel tank so all good.
Haven't really started the build yet, just dismantled and starting to see what needs doing. The new frame needed to be tidied up a bit so I gave it to Tjebe Bruin to work on, got it back on Friday but just noticed it is missing the top exhaust mount. Tjebe is away for a couple of months so might give it to Kev to sort out.
I also got some of those GPI radiators from China, one of the mounting points doesn't line up so Kev may be able to sort that out as well.
kelroy_leon
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kelroy_leon 6/12/2015 5:23pm
6/12/2015 5:23pm
Here are a few pictures of the '91. Seems to be a solid starting point.











kelroy_leon
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kelroy_leon 6/12/2015 5:25pm
6/12/2015 5:25pm
A few more. I will give it a good cleaning and see where I am at.











Staffy23
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Staffy23 6/23/2015 11:18pm
6/23/2015 11:18pm
Great condition, especially for age. To find anything like that here in Australia you would be doing very well.
sende
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sende 6/24/2015 10:43am
6/24/2015 10:43am
I like how there is a heartagram on the side number panels Grinning
kelroy_leon
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kelroy_leon 6/24/2015 3:31pm
6/24/2015 3:31pm
sende wrote:
I like how there is a heartagram on the side number panels Grinning
I have seen some interesting graphic choices on bikes but that is a first for me.

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sende
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sende 6/25/2015 11:04am
6/25/2015 11:04am Edited Date/Time 6/25/2015 11:05am
sende wrote:
I like how there is a heartagram on the side number panels Grinning
kelroy_leon wrote:
I have seen some interesting graphic choices on bikes but that is a first for me.
First for me too!
kelroy_leon
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kelroy_leon 7/10/2015 5:37pm
7/10/2015 5:37pm
I am on the look for the pink or blue plastics for this bike, like the ones in the UFO ad above. If anyone has any that they may want to part with, please let me know.

Thanks
zakcoe1
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zakcoe1 7/4/2016 5:27am
7/4/2016 5:27am
I need a new subframe for 91 kx 250 any ideas were I can get 1 from
nicko-31
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nicko-31 7/7/2016 10:47am
7/7/2016 10:47am
sende wrote:
I like how there is a heartagram on the side number panels Grinning
kelroy_leon wrote:
I have seen some interesting graphic choices on bikes but that is a first for me.
sende wrote:
First for me too!
So do you think there's a chance this might be one of Beelzebubs's former race bikes ??
ryancumuze
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ryancumuze 12/12/2020 1:27am
12/12/2020 1:27am Edited Date/Time 12/12/2020 1:27am
What is the tool called for the subframe fasteners?
sandman768
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sandman768 12/12/2020 6:21am
12/12/2020 6:21am
ryancumuze wrote:
What is the tool called for the subframe fasteners?
The subframe has Riv-nuts, that strip, become loose & fall into the subframe. You need a Rivit gun tool that comes with a selection of metric Riv-nuts. Harbor freight may have them. When the drilled out old rivers fall down into the subframe you can’t get them out, I used some spray construction foam to freeze them & keep them from rattling around. If you are going to rebuild the bike, start a build thread & post photos. You will get a lot of insight from many experienced builders in here. PSA: Don’t send your motor to Varner, or mention your political affiliation, tighten your sprocket bolts and don’t skip leg day👍

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