1992 YZ250 lockdown-teardown- completed with start up video

acerbis
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acerbis 4/4/2020 4:01pm
4/4/2020 4:01pm
sandman768 wrote:
Rear section refinished... [img]https://p.vitalmx.com/photos/forums/2020/04/04/416699/s1200_15899B50_042F_4C58_BBB7_086F0B34BDA2.jpg[/img]
Rear section refinished...
Looks factory. Good job.
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sandman768
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Saratoga Springs, NY US
sandman768 4/4/2020 4:48pm
4/4/2020 4:48pm
sandman768 wrote:
Rear section refinished... [img]https://p.vitalmx.com/photos/forums/2020/04/04/416699/s1200_15899B50_042F_4C58_BBB7_086F0B34BDA2.jpg[/img]
Rear section refinished...
acerbis wrote:
Looks factory. Good job.
Thanks...it was a lot of work for something that is covered up by the plastics & seat, but it is 100% correct now with good factory looking welds. Now I can start working on removing the Hong Kong seat cover to look at the rotted foam😂
sandman768
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sandman768 4/5/2020 7:20am
4/5/2020 7:20am
Seat foam is rotted....extra points for use of paper towels under seat foam😂


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sandman768
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sandman768 4/6/2020 9:45am
4/6/2020 9:45am
It’s a long way from being installed but, it was sitting on my bench and the parts showed up. Carb rebuild. Jetting back to stock.



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sandman768
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sandman768 4/9/2020 1:07pm
4/9/2020 1:07pm
Radiators back from ICW....better than they were, not a stellar job, but straight, broken tabs welded and pressure tested. The radiator grilles for these 91-92”s are NLA and very hard to find... these had been on bent radiators so long they were all deformed & twisted up. Now that the radiators are straight, I bolted them on & zip tied them to correct alignment, then used my heat gun to help them get their memory back. I also used the heat gun on the seat pan, as the rear corners were flared out and not aligned properly with the plastics. This feels a lot like working on a Suzuki😂





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sandman768
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sandman768 4/9/2020 1:12pm
4/9/2020 1:12pm
Not going to kill myself Sanding this tank, just an hr or 2 to get some nicks out. I plan on getting decals to cover the tank..


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sandman768
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sandman768 4/10/2020 7:42pm
4/10/2020 7:42pm
Engine teardown... think this needs a replate?

sandman768
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sandman768 4/10/2020 7:57pm
4/10/2020 7:57pm
The bad: cases will need some serious attention, the surfaces are all gouged up...needs all new bearings & seals. Clutch basket hammered.Pushrod worn. The good: transmission gears look usable, crank is tight... can’t find shift drum bearing in parts database?


38special
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38special 4/11/2020 7:58am
4/11/2020 7:58am
Great build. This is my #1 favorite bike of all time. Keep the updates coming!
sandman768
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sandman768 4/11/2020 8:20am
4/11/2020 8:20am
38special wrote:
Great build. This is my #1 favorite bike of all time. Keep the updates coming!
Thanks ..38special.... hit some snags with some really poor prior work on the engine...I”m currently looking for some better engine cases, but I may be able to salvage these...looks like the previous owner did more damage than good!
ledger
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TN US
ledger 4/11/2020 9:56am
4/11/2020 9:56am
After the other builds I've witnessed of yours...I know this one is gonna turn out top notch. Also, the white frame on these bike's look awesome. Good stuff sandman.
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sandman768
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sandman768 4/11/2020 10:53am
4/11/2020 10:53am
ledger wrote:
After the other builds I've witnessed of yours...I know this one is gonna turn out top notch. Also, the white frame on these bike's look awesome...
After the other builds I've witnessed of yours...I know this one is gonna turn out top notch. Also, the white frame on these bike's look awesome. Good stuff sandman.
Thanks ledger.... I will get it sorted... just going to take a little longer...I took another look at the cases... no way I will use them... I will keep plugging along with what I can do until some better cases are sourced. Here are some up close photos of what they look like....😂






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sandman768
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sandman768 4/11/2020 10:55am
4/11/2020 10:55am
Cheap aftermarket gaskets anyone?
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bonseff
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Frisco, TX US
bonseff 4/11/2020 12:10pm
4/11/2020 12:10pm
sandman768 wrote:
Cheap aftermarket gaskets anyone? [img]https://p.vitalmx.com/photos/forums/2020/04/11/419023/s1200_1EC77516_8CC5_4245_8B30_50F67F20F4DB.jpg[/img]
Cheap aftermarket gaskets anyone?
xacto knife and copper permatex Smile
sandman768
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sandman768 4/11/2020 1:15pm
4/11/2020 1:15pm
sandman768 wrote:
Cheap aftermarket gaskets anyone? [img]https://p.vitalmx.com/photos/forums/2020/04/11/419023/s1200_1EC77516_8CC5_4245_8B30_50F67F20F4DB.jpg[/img]
Cheap aftermarket gaskets anyone?
bonseff wrote:
xacto knife and copper permatex Smile
Yes, he could have just trimmed the gasket at the water outlet! An oem base gasket is 10$ from Yamaha... I just don’t understand why someone would cheap out on critical parts...
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Chance1216
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Carson, CA US
Chance1216 4/11/2020 3:29pm
4/11/2020 3:29pm
sandman768 wrote:
Cheap aftermarket gaskets anyone? [img]https://p.vitalmx.com/photos/forums/2020/04/11/419023/s1200_1EC77516_8CC5_4245_8B30_50F67F20F4DB.jpg[/img]
Cheap aftermarket gaskets anyone?
bonseff wrote:
xacto knife and copper permatex Smile
sandman768 wrote:
Yes, he could have just trimmed the gasket at the water outlet! An oem base gasket is 10$ from Yamaha... I just don’t understand why someone...
Yes, he could have just trimmed the gasket at the water outlet! An oem base gasket is 10$ from Yamaha... I just don’t understand why someone would cheap out on critical parts...
I always use OEM gaskets on those critical areas as well.
I went aftermarket once and much like that pic, the gasket didn’t line up properly. Kinda misleading when it says “EXACT MATCH” when ordering online.
sandman768
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sandman768 4/11/2020 6:09pm
4/11/2020 6:09pm
Oem levers & covers...


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sandman768
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sandman768 4/13/2020 10:35am
4/13/2020 10:35am
Part of the fun for me on these restores/ builds is learning new things, trying to solve problems and parts searches. This is the first YZ of this era that I have ever worked on. After reading up some on the powervalve design, I knew what potential wear items to inspect. Here are photos of the cylinder and powervalve. The first & last photos show the left powervalve & holder. Decent amount of wear on both, which can cause over rotation of the valve. The over rotation is not optional in either direction.I will replace the holder as it is much cheaper than the valve and it’s still available. Hopefully this will tighten any over rotation issues. Surprisingly even with this wear, the valve does not appear to protrude into the cylinder as I have read about



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YZed250
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Costa Mesa, CA US
YZed250 4/13/2020 10:38am
4/13/2020 10:38am
Subscribed!
Blarvick
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Waterford, MI US
Blarvick 4/13/2020 8:20pm
4/13/2020 8:20pm
Nice job so far! I had the same powervalve problem, i ended up adding a small amount of weld to the nub and grinding it back into shape.
sandman768
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sandman768 4/14/2020 6:41am
4/14/2020 6:41am
Blarvick wrote:
Nice job so far! I had the same powervalve problem, i ended up adding a small amount of weld to the nub and grinding it back...
Nice job so far! I had the same powervalve problem, i ended up adding a small amount of weld to the nub and grinding it back into shape.
Wish I had an aluminum welder! First thing I thought of...just a little dot on each contact point....I still may do that... not even sure if my welder guy is open for business right now.... there is a new holder/stopper on eBay, I made a bid, but the seller wants more than I can get one from RMC...
Brian_Bowles 4/17/2020 5:52am
4/17/2020 5:52am
My YZ125 was a light project. It started running after little efffort. I cleaned it up and put a new tank and plastic on it. It seemed to me that Yamaha stocked more parts than Honda but if they did not have it then the part was really hard to find. There are not as many YZ bikes still out there.
As always great job on your project.
sandman768
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sandman768 4/17/2020 6:28am
4/17/2020 6:28am
Brian_Bowles wrote:
My YZ125 was a light project. It started running after little efffort. I cleaned it up and put a new tank and plastic on it. It...
My YZ125 was a light project. It started running after little efffort. I cleaned it up and put a new tank and plastic on it. It seemed to me that Yamaha stocked more parts than Honda but if they did not have it then the part was really hard to find. There are not as many YZ bikes still out there.
As always great job on your project.
The 91-92 YZ”s are unique in many ways, luckily Yamaha made the Wr 250 which shares a lot of engine parts. As with all older bikes some parts will be a challenge locate in usable condition. Thanks for the kind words.....your CR came out great!
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MaxPower
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NJ US
MaxPower 4/17/2020 6:30am
4/17/2020 6:30am
You always do an amazing job with your bikes Sandman.
sandman768
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sandman768 4/17/2020 8:41am
4/17/2020 8:41am
MaxPower wrote:
You always do an amazing job with your bikes Sandman.
Thanks MaxPower...the 91-92 YZ”s are few and far between, at least around my area. It’s worth Doing a proper job on it.
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sandman768
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sandman768 4/17/2020 2:43pm
4/17/2020 2:43pm
Parts back from vapor blasting...



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Yz229
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San Diego, CA US
Yz229 4/17/2020 3:37pm
4/17/2020 3:37pm
Love that gen. Looking great so far!
sandman768
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sandman768 4/17/2020 4:51pm
4/17/2020 4:51pm
Yz229 wrote:
Love that gen. Looking great so far!
Thanks Yz229.... 90”s bike rock 👍
Brian_Bowles 4/17/2020 9:47pm
4/17/2020 9:47pm
Brian_Bowles wrote:
My YZ125 was a light project. It started running after little efffort. I cleaned it up and put a new tank and plastic on it. It...
My YZ125 was a light project. It started running after little efffort. I cleaned it up and put a new tank and plastic on it. It seemed to me that Yamaha stocked more parts than Honda but if they did not have it then the part was really hard to find. There are not as many YZ bikes still out there.
As always great job on your project.
sandman768 wrote:
The 91-92 YZ”s are unique in many ways, luckily Yamaha made the Wr 250 which shares a lot of engine parts. As with all older bikes...
The 91-92 YZ”s are unique in many ways, luckily Yamaha made the Wr 250 which shares a lot of engine parts. As with all older bikes some parts will be a challenge locate in usable condition. Thanks for the kind words.....your CR came out great!
Thanks!
sandman768
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sandman768 4/21/2020 2:42pm
4/21/2020 2:42pm
Good day for swingarm & linkage bearing replacement....

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