1991 YZ250 Build

reggie426
Edited Date/Time 7/1/2017 3:22am
Hi all, new member here, joined after searching a few things and found this site.

I've picked up a running 1991 YZ250 for 2 bottles of Jack Daniels, and I've decided to do a frame up rebuild as a fun project. I've always been a 4 stroke guy so this is all new territory for me. The bike has fuel running out the overflow of the carby and first gear doesn't work but it starts cold after 4 or 5 kicks and is complete.





I'm aiming to have it looking like this





but without the Ohlins bits obviously.

I'm going to have to split the cases to get to the gearbox, and I'll do top and bottom ends, bearings etc at the same time. I have a spare 1995 engine here that's apparently seized, I've stripped the cylinder off and the pistons in backwards for a start but not sure what else is wrong.

So, my first question is, is the '95 tranny different to the 91? Can I use the gear set from that bike in my build?

Thanks in advance for any answers.

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MXM
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pickstick BD
MXM 7/6/2014 8:29am
7/6/2014 8:29am Edited Date/Time 7/6/2014 8:31am
I don't know about the tranny swap but when you are ready to ride don't forget your jersey.

reggie426 7/6/2014 4:26pm
7/6/2014 4:26pm Edited Date/Time 7/6/2014 4:27pm
Sweet, thanks for the link, I'll email them and ask. I've seen them on ebay, they have a 91 tranny listed there in case this one doesn't fit.

I was thinking of doing a 91 Bradshaw/Dubach build but the pink seat of that year makes me feel ill. And I do love red/white yami's

That Jersey is nice but I'm not fast enough to do it justice!
reggie426 7/7/2014 5:21am
7/7/2014 5:21am
Stopped by the yami dealer after work today, they kindly printed off both parts lists for both gearboxes. The numbers are the same except for some have different codes at the beginning, is this just to identify the year? ie the 91 has 2VM and the 95 has 4MX. The 95's engine number starts with 4MX

The Shop

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Joe_Stricklin 7/7/2014 7:42am
7/7/2014 7:42am
Here is my 89 YZ250 under construction. Thought about the Chesterfield decals but decided to got stock from EVOMX.
Kinda blurry sorry for that.

Still looking for someone to do the number plates similar to these.



reggie426 7/7/2014 3:08pm
7/7/2014 3:08pm
Nice, an 89/90 is what I originally wanted to do but a guy answered my wanted ad with the 91 and it was too good to pass on.

reggie426 7/21/2014 8:52pm
7/21/2014 8:52pm Edited Date/Time 7/21/2014 8:53pm
Managed to strip some down over the weekend, found a few little surprises.




The frame has been repaired before, where the left side subframe meets the main frame. Badly done, going to grind it up and my bro in law will tig it better, before powdercoating. Also missing a side plate bracket which I'll have to make up too.




Bottom end doesn't seem to bad but I'll replace it anyway. The casing's broken at the rear where the swingarm/engine mount bolt goes through, I'll have to source another '91 casing to keep the '91 engine numbers, which is a bummer. Also the cylinder head has been resleeved, I was hoping it was the original nikosil bore but oh well.

Rear shock has blown out, and one of the front fork tubes has a deep gouge in it.

I'm also starting to lean away from the Chesterfield graphics and maybe just do a stock rebuild.
MaxPower
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MaxPower 7/22/2014 2:28am
7/22/2014 2:28am
What was three first year the Chesterfield Team ran black plastic?
Donny Schmidts passing has always upset me for a person I have never known.
His story of a driven kid from Minnesota rising to world champion is such a great one to a kid passing from an illness that turned so trajic.
Seeing a Chesterfield YZ makes me think of him as soon as I see one.
Bono480
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Bono480 7/22/2014 2:38am
7/22/2014 2:38am
reggie426 wrote:
Hi all, new member here, joined after searching a few things and found this site. I've picked up a running 1991 YZ250 for 2 bottles of...
Hi all, new member here, joined after searching a few things and found this site.

I've picked up a running 1991 YZ250 for 2 bottles of Jack Daniels, and I've decided to do a frame up rebuild as a fun project. I've always been a 4 stroke guy so this is all new territory for me. The bike has fuel running out the overflow of the carby and first gear doesn't work but it starts cold after 4 or 5 kicks and is complete.





I'm aiming to have it looking like this





but without the Ohlins bits obviously.

I'm going to have to split the cases to get to the gearbox, and I'll do top and bottom ends, bearings etc at the same time. I have a spare 1995 engine here that's apparently seized, I've stripped the cylinder off and the pistons in backwards for a start but not sure what else is wrong.

So, my first question is, is the '95 tranny different to the 91? Can I use the gear set from that bike in my build?

Thanks in advance for any answers.

Where the hell do you find a sweet deal like that in Aus!!!! People usually want like $2500 at least for something like that haha
reggie426 7/22/2014 3:58am
7/22/2014 3:58am Edited Date/Time 7/22/2014 4:07am
I posted a wanted ad on gumtree looking for an 89/90 for a project, guy rang me within an hour asking if I wanted a 91 instead. I wasn't too keen until he said it runs and he only wanted two bottles of JD for it to make some room. Naturally I jumped at it before he could change his mind.

He also gave me a 95 frame, seat, forks, swing arm, exhaust, wheels, shock and engine as extra pieces but I couldn't use them (except the transmission) so I gave them away for free on gumtree too. Payed it forward.
reggie426 7/22/2014 4:02am
7/22/2014 4:02am Edited Date/Time 7/22/2014 4:04am
MaxPower wrote:
What was three first year the Chesterfield Team ran black plastic? Donny Schmidts passing has always upset me for a person I have never known. His...
What was three first year the Chesterfield Team ran black plastic?
Donny Schmidts passing has always upset me for a person I have never known.
His story of a driven kid from Minnesota rising to world champion is such a great one to a kid passing from an illness that turned so trajic.
Seeing a Chesterfield YZ makes me think of him as soon as I see one.
I may be wrong but I think 94? Wasn't 92 and I've seen 94 models in black.

I only ever saw pics of Donny Schmidt in magazines as a kid, but I knew enough about him to be saddened by his passing.
reggie426 8/13/2014 4:37am
8/13/2014 4:37am
Just bought a pair of forks off ebay, as mine have a deep gouge in one of the fork tubes. The seller says he's 90% certain they came off one of John Dowds bikes, but he can't confirm. The bike had ohlins rear shock and other bits that he's already sold. I'm not convinced as he was on Honda in 91 but who knows.

Is there a way to find out, when I strip them down to rebuild? What should I look for?

I'm not fussed if they're not but would be a nice talking point when I'm done restoring the YZ if they had a history.
reggie426 9/8/2014 10:02pm
9/8/2014 10:02pm Edited Date/Time 9/8/2014 11:06pm


Just had this delivered, didn't remember how pink this bike was...

Shock spring off at powdercoaters, 2 sets of forks on the bench ready to make one good set when the seals, bushes etc arrive. One more thing to tig weld on frame then off to powdercoat that too. Can't wait for all the bits to be ready for rebuild and reassembly

edit: found the NOS seatcover on ebay, $50 to buy including postage from the states to aus Pretty happy!
reggie426 9/12/2014 8:08pm
9/12/2014 8:08pm
Dubby McDubs wrote:
Nice build! Keep the detail coming!
Thanks, I will! I've decided not to cannibalise parts from the 95 engine and keep it complete. If anyone has a build idea for it let me know, or I might end up just selling it complete if nothing tickles my fancy
tls90lx
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tls90lx 10/3/2014 8:20am
10/3/2014 8:20am Edited Date/Time 10/3/2014 8:21am
Im from Minnesota, My first year racing was 1992, I got to see Donny practice on his Chesterfeild YZ 250 in Grantsburg Wisconsin, he was a class act awesome guy!! Im going to try and fins a YZ one of these days as well to try and clone his bike or Bradshaw. Good luck with the build!
reggie426 3/27/2015 10:03pm
3/27/2015 10:03pm
Just a little update, had frame powdercoated, and other alloy bits glass beaded to get back to bare clean metal. Intend to rub back by hand then clear coat. Have 2 sets of forks to make one good set out of and 2 rear shocks. Not finding much time to do anything but it's going along slowly.









reggie426 2/21/2016 5:02pm
2/21/2016 5:02pm
So after not touching it for a while due to having a baby and other things, I've started putting this thing back together. Any tips with getting the bushes etc out of the shock and swing arm linkages?


Pit Row

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markit
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markit 2/21/2016 9:52pm
2/21/2016 9:52pm
So how's it really feel to bare a child?

lol, nice build
reggie426 2/21/2016 10:34pm
2/21/2016 10:34pm
You know when you tighten a nut and the spanner slips and your knuckles hit the foot pegs? Like that times 1000

Cheers, hopefully it turns out like I hope
AustinFitz90 2/22/2016 1:59am
2/22/2016 1:59am Edited Date/Time 2/22/2016 2:00am
Awesome bike! I'll definitely be following this build. I actually just started on a 1990 myself. I've been trying to decide between just sprucing it up a bit, and doing a full on bare frame restoration. I've been leaning towards going all the way, and I think your '91 just made up my mind on that. Can't wait to see more pics! Here's my '90


Chawnz
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Chawnz 2/22/2016 12:12pm
2/22/2016 12:12pm
reggie426 wrote:
[img]https://p.vitalmx.com/photos/forums/2014/09/08/64676/s1200_image.jpg[/img] Just had this delivered, didn't remember how pink this bike was... Shock spring off at powdercoaters, 2 sets of forks on the bench ready to...


Just had this delivered, didn't remember how pink this bike was...

Shock spring off at powdercoaters, 2 sets of forks on the bench ready to make one good set when the seals, bushes etc arrive. One more thing to tig weld on frame then off to powdercoat that too. Can't wait for all the bits to be ready for rebuild and reassembly

edit: found the NOS seatcover on ebay, $50 to buy including postage from the states to aus Pretty happy!
Wow that seat cover is an amazing find! Very jealous!
Andy86
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Andy86 2/22/2016 4:43pm
2/22/2016 4:43pm
reggie426 wrote:
So after not touching it for a while due to having a baby and other things, I've started putting this thing back together. Any tips with...
So after not touching it for a while due to having a baby and other things, I've started putting this thing back together. Any tips with getting the bushes etc out of the shock and swing arm linkages?


You want some threaded bar size m8 some strong washers a few nuts a couple of sockets one slightly smaller od than the bushes and one socket slightly larger id than the bushes i can post pic up

If your unsure what i mean
reggie426 2/23/2016 2:52am
2/23/2016 2:52am
Andy86 wrote:
You want some threaded bar size m8 some strong washers a few nuts a couple of sockets one slightly smaller od than the bushes and one...
You want some threaded bar size m8 some strong washers a few nuts a couple of sockets one slightly smaller od than the bushes and one socket slightly larger id than the bushes i can post pic up

If your unsure what i mean
I think I do, large socket on the back, thread through the linkage and small socket on the front, then nuts and washers to press it out? If you have pics that would help but I could prob find some on the net.

Same process for the seals on the bottom of the swing arm where the linkage meets?

Going to tackle making one decent set of forks this weekend
reggie426 2/23/2016 2:55am
2/23/2016 2:55am
AustinFitz90 wrote:
Awesome bike! I'll definitely be following this build. I actually just started on a 1990 myself. I've been trying to decide between just sprucing it up...
Awesome bike! I'll definitely be following this build. I actually just started on a 1990 myself. I've been trying to decide between just sprucing it up a bit, and doing a full on bare frame restoration. I've been leaning towards going all the way, and I think your '91 just made up my mind on that. Can't wait to see more pics! Here's my '90


Nice bike, that's what I was looking for when this 91 was found. Love the red/white, still have a brand new Doug Henry red/white one industries kit for 06-09 in the shed waiting for a bike to go on
reggie426 2/4/2017 7:21pm
2/4/2017 7:21pm
Been awhile, don't have a lot of time to get back to this plus moved house so things got stored for a while. But, starting to put things back together.



Got lucky with the engine, I had a '95 engine and some parts I couldn't use, advertised it and the guy just happened to have a complete engine that seems in good order so we swapped. Just got to tear it down, replace bearings etc and recondition the top end.





Whymee
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Whymee 2/7/2017 5:01pm
2/7/2017 5:01pm
Nice find/build! I will be following this close.

I also have a 91 that is getting ready for the build table. Probably next winter. I have 2 others I am trying to finish up now. I would have started this winter but I am having a hard time finding another frame. patience is not my virtue. Additionally the 91 I have just so happens to have a Ohlins 360 kit on it. It is my personal holy grail.

If anyone has a 91 frame or roller (or maybe a 92) please get in touch with me!
socalsand
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socalsand 2/22/2017 1:43am
2/22/2017 1:43am
reggie426 wrote:
Hi all, new member here, joined after searching a few things and found this site. I've picked up a running 1991 YZ250 for 2 bottles of...
Hi all, new member here, joined after searching a few things and found this site.

I've picked up a running 1991 YZ250 for 2 bottles of Jack Daniels, and I've decided to do a frame up rebuild as a fun project. I've always been a 4 stroke guy so this is all new territory for me. The bike has fuel running out the overflow of the carby and first gear doesn't work but it starts cold after 4 or 5 kicks and is complete.





I'm aiming to have it looking like this





but without the Ohlins bits obviously.

I'm going to have to split the cases to get to the gearbox, and I'll do top and bottom ends, bearings etc at the same time. I have a spare 1995 engine here that's apparently seized, I've stripped the cylinder off and the pistons in backwards for a start but not sure what else is wrong.

So, my first question is, is the '95 tranny different to the 91? Can I use the gear set from that bike in my build?

Thanks in advance for any answers.

When your bike is all done and your ready for the handle bar moto pad like on that bike, look me up. I recreate the old bar pads. I made this one for a guy.
ddr0986@aol.com





lorenzo de medici 7/1/2017 3:22am
7/1/2017 3:22am
reggie426 wrote:
Hi all, new member here, joined after searching a few things and found this site. I've picked up a running 1991 YZ250 for 2 bottles of...
Hi all, new member here, joined after searching a few things and found this site.

I've picked up a running 1991 YZ250 for 2 bottles of Jack Daniels, and I've decided to do a frame up rebuild as a fun project. I've always been a 4 stroke guy so this is all new territory for me. The bike has fuel running out the overflow of the carby and first gear doesn't work but it starts cold after 4 or 5 kicks and is complete.





I'm aiming to have it looking like this





but without the Ohlins bits obviously.

I'm going to have to split the cases to get to the gearbox, and I'll do top and bottom ends, bearings etc at the same time. I have a spare 1995 engine here that's apparently seized, I've stripped the cylinder off and the pistons in backwards for a start but not sure what else is wrong.

So, my first question is, is the '95 tranny different to the 91? Can I use the gear set from that bike in my build?

Thanks in advance for any answers.

socalsand wrote:
When your bike is all done and your ready for the handle bar moto pad like on that bike, look me up. I recreate the old...
When your bike is all done and your ready for the handle bar moto pad like on that bike, look me up. I recreate the old bar pads. I made this one for a guy.
ddr0986@aol.com





I will need a pad thanks .

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