Author Topic: Yamaha SRX250  (Read 1016 times)

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Offline Diablo007

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Yamaha SRX250
« on: April 08, 2021, 03:38:51 AM »
Another of the many projects going on.  Actually there are two of these.  Both are works in progress and are up for sale.  One needs the rebuilt carburetor installed, the fork boots cut off to check the condition of the forks, and a test run.  The other hasn't run in years but is also complete.  I have a rebuilt carburetor for it also.

Pics is of the former.
2 stroke junkie:
1973 Yamaha RD350 (a bitsa); 1974 Yamaha DT125A; 1975 Yamaha RD350B; 1983 Suzuki RG250 (YamaGamma project); 1984 Yamaha RZ350; 1987 Yamaha YSR50T; and an RD200 café racer project has just been proposed... :D

Offline Diablo007

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Re: Yamaha SRX250
« Reply #1 on: April 08, 2021, 04:00:28 AM »
Forgot to mention.  Both have JDM center stands.  the one in the pic has the proper fasteners but needs a stop made.  I'm guessing the JDM pipes had a stop on them for the center stand.

The other has a JDM center stand also, but it didn't come with the fasteners.

Both were bought off Yahoo auctions in Japan.  Sometimes it's nice having family in Japan.  Other times is sucks because COVID keeps you from visiting them.
2 stroke junkie:
1973 Yamaha RD350 (a bitsa); 1974 Yamaha DT125A; 1975 Yamaha RD350B; 1983 Suzuki RG250 (YamaGamma project); 1984 Yamaha RZ350; 1987 Yamaha YSR50T; and an RD200 café racer project has just been proposed... :D

Offline Diablo007

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Re: Yamaha SRX250
« Reply #2 on: May 04, 2021, 12:33:57 AM »
It's running  :metal:  Didn't at first, helps if you connect the plug cap  :bang:  Wouldn't idle without the choke.  Realized it had a vacuum feed petcock, plugged the vacuum (was running it off a remote tank) and it ran and idled fine  :bang:  Yeah it's been a while since I've dug this deep in anything this 'modern'  :dawg:

Some plastic welding and it should be good to go.  Peeked under the decomposing fork gaiters and the forks look good.  I'll have to completely remove them to be sure.  If my wife likes it it's hers.  If not it will be up for sale.

The hardest part of the build was finding a new carb slide.  They aren't made anymore and the NOS one I found on eBay was pretty expensive.  The I came across this site:

http://jbmindustries.com/YDLS.html

The replacement diaphragm seems to be working fine.  They sell other items that may help some of you out with projects.
« Last Edit: May 04, 2021, 01:43:08 AM by Diablo007 »
2 stroke junkie:
1973 Yamaha RD350 (a bitsa); 1974 Yamaha DT125A; 1975 Yamaha RD350B; 1983 Suzuki RG250 (YamaGamma project); 1984 Yamaha RZ350; 1987 Yamaha YSR50T; and an RD200 café racer project has just been proposed... :D

Offline Diablo007

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Re: Yamaha SRX250
« Reply #3 on: June 27, 2021, 04:01:00 AM »
So...rebuilt the petcock, installed new exhaust gaskets, and started up.  Wants to stall with the choke off while rolling on the throttle until it's warmed up.  I'm guessing I don't have the carb setup quite right.  Took it for a test ride, runs nicely.  Noticed fuel coming out of the bottom of the float bowl after it was shut off and cooling down.  Thought the the drain screw might be loose so opened and closed it.  Fuel still coming out.  My best guess is that the overflow runs through the same output but the other carb for the other SRX is at the shop.  Can anyone confirm that it may be a float height issue?  I did set the fuel level with a clear tube, that's the reason for the confusion.
2 stroke junkie:
1973 Yamaha RD350 (a bitsa); 1974 Yamaha DT125A; 1975 Yamaha RD350B; 1983 Suzuki RG250 (YamaGamma project); 1984 Yamaha RZ350; 1987 Yamaha YSR50T; and an RD200 café racer project has just been proposed... :D

Offline pidjones

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Re: Yamaha SRX250
« Reply #4 on: June 27, 2021, 06:43:26 AM »
Don't know your carb, but some have an internal brass overflow tube (port shared with the drain) that develops tiny splits. I have successfully repaired some with solder, but it isn't a sure thing. Test it by filling the bowl (over a sink) with >91% isopropyl alcohol and watching for leakage.
"Love 'em all.... Let GOD sort 'em out!"

Offline dgorms

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Re: Yamaha SRX250
« Reply #5 on: July 28, 2021, 10:42:01 PM »
Excellent platform for a YZ- 490 motor.
rz,r5,ds7,srx,fzr400rr,vfr,cl77,s90, F-7,CL 77, CA-77,ad infinitum

Offline quocle603

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Re: Yamaha SRX250
« Reply #6 on: August 07, 2021, 04:02:17 PM »
I saw one of these at a bike show earlier this year. What a cool looking bike, they are very far and in between.
Do not underestimate the power of a two-stroke.

1975 Yamaha RD350 (modified), 1973 Yamaha RD350 (stock), 1971 Suzuki T500, 1981 Yamaha XS650 HS2, 1982 Honda MB5, 1980 Puch Maxi, 1979 Puch Magnum, 1993 Tomos Bullet, 2003 Malaguti Firefox F15 LC