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92 yz 250

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I just bought a 1992 yz 250. my first 2 stroke in 10 or 12 years. I cant wait to ride this bike. I have a few questions. what is the bore and stroke of this bike in stock form? how big can it be bored? what years cylinders will interchange with a 92? what year rear wheels will interchange? thanks for any help I will try to get a ride in next weekend:ride::bonk::ride::smirk:

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You will find we have ALL the answers here for the 2005 and up YZs, MOST of the answers for 1996-2004, MANY answers for 1993-1995, but any older than that and pickings get a little slim. :bonk:

The 1988-1992 YZs were all pretty similar, if that helps at all...

http://www.motodacross.com/yamaha/yz250.htm

Some guys go through online parts lists to see if numbers match between years to verify interchangeability.

http://www.cyclepartswarehouse.com/default.asp

http://www.ncy-motorsports.com/

http://shop.thumpertalk.com/oem.asp

http://www.ronayers.com/

http://shop.zanottimotor.com/content/parts-department

For cylinder swap-ability, check with an engine builder like Eric Gorr

or maybe a cylinder rebuilder like L.A. Sleeve would know.

http://www.eric-gorr.com/cylinder%20repairs.html

http://www.lasleeve.com/offroad-motocross

http://kustom-kraft.com/YAMAHAKITS.html

Good luck!

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Yamaha started using that generation engine in '88 (maybe '89) I believe. They used it all the way until '98 making minor revisions along the way. Anything up until '98 should work fine for your '92.

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Yamaha started using that generation engine in '88 (maybe '89) I believe. They used it all the way until '98 making minor revisions along the way. Anything up until '98 should work fine for your '92.

Yup, any YZ250 (or WR250 2 stroke) from '89-'98 will bolt-up. Several companies can do big-bores up to 300cc. Try LA Sleeve or Eric Gore.

I believe wheels will interchange too, the bearing diameters might have changer in there somewhere (somewhere around '93), but the hubs, and sprockets should be the same.

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:thumbsup:You guys are great with all youre info on YZs . I appreciate just learning, even if i dont own a 92 YZ ( love em all though)

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get on it and ride it and get it jetted good, my 92 wr is fast ! might want to save that money on big bore stuff, but use it on suspension instead. just my 2 cents.................if your trail riding its faster then you can ride stock .

just sayin !

good luck with your project, i love my wr, had it since new and will never part with it ever !

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get on it and ride it and get it jetted good, my 92 wr is fast ! might want to save that money on big bore stuff, but use it on suspension instead. just my 2 cents.................if your trail riding its faster then you can ride stock .

just sayin !

good luck with your project, i love my wr, had it since new and will never part with it ever !

I plan to ride it mostly in the sand dunes. I have allready bought a second back wheel. one for A paddle and one for A knobby.I will ride it till I brake something. I found A 96 yz 250 cylinder and power valve bored to 74 mm and its pretty cheap. so I was curios if it would fit. every two stroke I have owned has ate a piston sooner or later my 85 tri-z went thru 4 in 7 years. so I am planing on repairs before it blows.If the boingers dont work for me they will be on top of my list for mods.thanks again to everyone for all the info and advice

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88 -98 use the same basic bolt pattern where the base gasket sets,

88/89 uses a different rod length so overall cylinder hieght is different

95 and later use a different exhaust port, the pipe goes into compared to a go around joint at the cylinder.

the 94 would probably be the most sought after cylinder to be able to fit right on with everything with no fabrication or measuring/machining but a good 92 cylinder in the hands of someone like Eric Gorr could be just as strong but cheaper than buying a jacked up cylinder and having it repaired

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88 -98 use the same basic bolt pattern where the base gasket sets,

88/89 uses a different rod length so overall cylinder hieght is different

95 and later use a different exhaust port, the pipe goes into compared to a go around joint at the cylinder.

the 94 would probably be the most sought after cylinder to be able to fit right on with everything with no fabrication or measuring/machining but a good 92 cylinder in the hands of someone like Eric Gorr could be just as strong but cheaper than buying a jacked up cylinder and having it repaired

I was woried about finding a 74mm piston. the bore looks really good. the power valve is a little rough. it looks like they ground on it with 40 grit sand paper. so an 96 cylinder will bolt up to a 92 motor but a 96 exhaust will be needed also?

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i found a couple piston kits on ebay for under 35 with shipping, oem stuff, if you don't get in a hurry there are lots of parts for sale, just got to keep an eye out for them, closeouts and such. i have more spares now then i will ever wear out .....................

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I was woried about finding a 74mm piston. the bore looks really good. the power valve is a little rough. it looks like they ground on it with 40 grit sand paper. so an 96 cylinder will bolt up to a 92 motor but a 96 exhaust will be needed also?

93 and later pipes are "lowboy" pipes where the stinger wraps under the shock resorvoir I doubt it will fit but couldnt say for sure

74mm piston? I thought the stock bore was 68 with a 2mm oversize available? must be some other overbore I am not familiar with do your homework on that

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93 and later pipes are "lowboy" pipes where the stinger wraps under the shock resorvoir I doubt it will fit but couldnt say for sure

74mm piston? I thought the stock bore was 68 with a 2mm oversize available? must be some other overbore I am not familiar with do your homework on that

I have a 91 ill see if a 93 and up pipe can be made to fit tomorrow .

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When i first bought my yz, i was told it was a 93. I ordered a new pipe and silencer for it and it didnt fit. I found the vin and found it was a 91, then reordered the pipe and it fit very easily.

So in my experience it will not fit.

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I think I will wait for a 92 cylinder to show up.I gonnna ride on new years day. the dunes are usually empy that day:ride::smirk::ride: cant wait I have been on a xr 600 for the past 10 years a 2 stroke is gonna be fun:banana::bonk::banana:

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I have a 91 cylinder . Don't know what shape its in yet have to pull it off the bike .

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Im thinking my shock linkage is a little worn my first investment for this bike in probally gonna be a rebuild kit for my shock linkage

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I'll sell the cylinder . I'll have it pulled of Tuesday night . To see how it looks .

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The 91 will work the only difference between is the exhaust port on 91 is completely round where as the 92 is D shaped I actually have a 92 cylinder on my 91 yz

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