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M2statz
Posted on Monday, September 17, 2012 - 11:23 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

Thinking about taking on a winter project bike. It is a 1975 Yamaha RD250, most everything is there may need new bars and a whole front tire with brake and all, but the engine turns over with compression, haven't put a meter on it yet. Just wondering if anybody knows what that compression should be and what else I should look for before buying? Thanks.
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Ourdee
Posted on Monday, September 17, 2012 - 11:50 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

One of my first street bikes.
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Sleez
Posted on Monday, September 17, 2012 - 12:04 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

115 plus is good, as far as the rd board says, anything 90 or lower needs rebuild.

take it with a grain of salt, info i found online.

i have had a few 350s and a 400, want one again someday.
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86129squids
Posted on Monday, September 17, 2012 - 12:12 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

Been drooling over these here in TN:

http://knoxville.craigslist.org/mcy/3233046723.htm l

Also, the search turned up a Maxim X of all things!

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Britchri10
Posted on Monday, September 17, 2012 - 12:12 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

Yamaha RD250B: My first road bike in 1978.
Yamaha RD250E: My second road bike in 1979.
Yamaha RD350E: My third road bike in 1980.

Loved them all. Would love another now!
Chris C
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Mr_grumpy
Posted on Monday, September 17, 2012 - 12:46 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

Ohoh, I can hear that Crazy Frog coming!

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Oldog
Posted on Monday, September 17, 2012 - 12:57 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

I wondered when this guy would show up again

** Ding * Ding **
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Mr_grumpy
Posted on Monday, September 17, 2012 - 01:00 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

Chris & I are "of an age" as you might say, & I feel I should explain to our colonial cousins, that back in the mists of time that were our youth's, you could ride up to 250cc without having to take a test, on what's known as a "provisional licence".
Hence most of us our age from the UK cut our teeth on 250 Jap strokers.
There were of course the odd weirdos who rode MZ & CZ contraptions or 4 stroke Hondas, but we don't talk about them.

My old friend Nick in Austin has just picked up his first love again, a Suzuki T250 Hustler.

I did a couple of conversions on the old DS 250 Yams for people, barrels, pistons, heads carbs & oiling gear from a YR5 350 "Roadburner" would bolt right up.

I'm still sort of looking for a Suzuki TS 250 M, or a T 500 K "Titan".
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Oldog
Posted on Monday, September 17, 2012 - 01:03 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

There were of course the odd weirdos who rode MZ & CZ contraptions

Hey I had a 250 CZ mx bike when I was decades younger

'course some folks would say I'se odd
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Reepicheep
Posted on Monday, September 17, 2012 - 01:41 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

I did a 71 Kawasaki 250 2 stroke. It was fun and ran great, but pretty much left me at a dead end.

Lousy fuel economy to be a commuter, too heavy and parts too expensive to be a dirt bike, and two stroke are awfully primitive for street use (smoking and leaking and fouling plugs...)

Many of the parts were dirt cheap. Some parts were a little expensive. But two parts ended up being both necessary and insanley expensive... throttle assembly and cables and replacement pistons. The piston in particular was the real problem.

I paid $75 for the bike, got lucky finding a piston, but to replace that one I was looking at $100+ for the piston (with a shorter lifespan). The throttle assembly with cables was going to be $300+ by the time I replaced the necessary boots.

So it's fun, but beware of little landmines that you don't see coming that can cost a fortune.

I sold it (for a loss) and bought a 78 KZ-400 (parallel twin 4 stroke). Much more fun, easier to get parts for, and when I am done it's going to be a great little 60 MPG commuter toy.

I do like 2 strokes for my dirt bikes though... all the power, half the weight and cost...
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Natexlh1000
Posted on Monday, September 17, 2012 - 02:41 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

Just a FYI: a two stroke that has been sitting idle for a long time won't have much compression to speak of.
You have to shoot some oil in there.

I don't have experience with old motorcycle engines but have woken up many "barn find" lawnboys and chainsaw engines.

When not in use, the reedvalves like to corrode fast, further hampering your attempts to get it to inhale and not exhale.

Keep us posted on how you do!
I have been having a hankering for a stroker myself recently.
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Mr_grumpy
Posted on Tuesday, September 18, 2012 - 05:05 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

For a 2 stroke that had been sitting a long time we always used to fire a good dose of "Redex" down the plug holes.

Let it sit for a few days then "kick" as much as possible out before installing plugs pre-heated on the gas cooker (sorry mum).

Hint, don't start it up on wash day! DAMHIK.

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Lemonchili_x1
Posted on Thursday, September 20, 2012 - 06:32 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

So have you bought it???

When I got my license we had a similar system to Mr G. While me and my friends were on our "Learners" then "P's" (provisional license) we were limited to 250cc. With all the wisdom of being 17 years old one of our motto's was "Sick of life in the fast lane? Buy a four-stroke!"

There were a few of us at school (6 or 7) and we rode a mix of Yamaha RD's and RZ's (aka YPVS to the Poms), Suzi RG's, and Honda VT's and Kawasaki GPz's. Amazingly, and thankfully, we all survived those first few years on the road. I know at least 4 of those friends still ride : )

My first bike when I bought it...

RD250LC before


...and a few months later...

RD250LC after


I'd love another one as a resto project : )
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Brumbear
Posted on Thursday, September 20, 2012 - 07:01 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

125 but a top end on a 2 stroker air cooled takes about 15 min to do
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M2statz
Posted on Thursday, September 20, 2012 - 04:08 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

Thanks for all the in put guys!! The more I look into the bike and research parts etc. the more closer to the fence I get. Where as the bike is clean, the engine turns over with compression at 120, I am just a little nervous about parts availability and cost. I have never taken on a project like this before. The current owner is in no hurry to sell so I have some time. Will try to get over to his place this week to take some pictures.
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Kenm123t
Posted on Thursday, September 20, 2012 - 04:57 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only) Ban Poster IP (Custodian/Admin only)

check out Walnecks classic motorcycle trader They have bunch of 2 stroke vendors talk with them
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