cosworth said:
Yeah, I know that feeling when you've just buttoned everything down, you dont really want to take it apart again! Will look nifty with matching clocks for sure.
Yamaha SR250 - A clean standard build
- Thread starter JadusMotorcycleParts
- Start date
Yeah, I know that feeling when you've just buttoned everything down, you dont really want to take it apart again! Will look nifty with matching clocks for sure.
Side note...
I came across this SR250 about 2 years ago now. I first saw/heard it on a youtube video that has since been taken down
I googled for hours, on several separate occasions just to be able to find these two pictures - which I found on a Japanese forum somewhere.
It has to be one of the coolest SRs I have seen and definitely the most race prepped/intentional SR250 I have ever seen. Even though it still has lights and everything, it looks like it has been set up for track days etc and that was what the video showed as well. I see so many custom parts. The most interesting to me is probably:
_ The wheel/hub conversion/adaptation - look sick!
_ The flatslide pumper carb (wonder what throat size it has?)
_ The exhaust - it must be custom made and looks single walled as well
_ The front guard is real nice
_ The tank, obviously
_ The switch of the foot controls - why would someone set it up like this? Someone who was/is used to the old British set up with the brake on left, shifter on the right? Pretty awesome linkage set up there anyway
_ The crankcase breather catch-tank thingy. Whats going on there?
I would love to know if anyone knows any more about this bike and/or its owner. I would really like to know if there was many internal engine mods done too - I suspect there would have been. So cool!
Any takers?
I came across this SR250 about 2 years ago now. I first saw/heard it on a youtube video that has since been taken down
I googled for hours, on several separate occasions just to be able to find these two pictures - which I found on a Japanese forum somewhere.It has to be one of the coolest SRs I have seen and definitely the most race prepped/intentional SR250 I have ever seen. Even though it still has lights and everything, it looks like it has been set up for track days etc and that was what the video showed as well. I see so many custom parts. The most interesting to me is probably:
_ The wheel/hub conversion/adaptation - look sick!
_ The flatslide pumper carb (wonder what throat size it has?)
_ The exhaust - it must be custom made and looks single walled as well
_ The front guard is real nice
_ The tank, obviously
_ The switch of the foot controls - why would someone set it up like this? Someone who was/is used to the old British set up with the brake on left, shifter on the right? Pretty awesome linkage set up there anyway
_ The crankcase breather catch-tank thingy. Whats going on there?
I would love to know if anyone knows any more about this bike and/or its owner. I would really like to know if there was many internal engine mods done too - I suspect there would have been. So cool!
Any takers?
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Heres the tacho block off/blanking plug in context... Both in the head and in the speedo drive hole.
The idea is that I will be able to re-use the original clip that held the cable fitting in place. Otherwise I will hunt down the correct size inside circlip.
The idea is that I will be able to re-use the original clip that held the cable fitting in place. Otherwise I will hunt down the correct size inside circlip.
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I Had a chance to tidy up the frame a bit too - remove some tabs and clean some welds. I dont really like to touch the welds, but the ones on this bike were so ugly that some of them required a little attention.
I never got the key for the head stem lock when I got the bike - rendering it useless. So I decided to cut it off and smooth it. I have seen someone else do this and it looked good
My effort wasn't so pretty but I will either fill the holes with weld and smooth it out or use filler (if I decide to spray paint instead of powder coat).
I never got the key for the head stem lock when I got the bike - rendering it useless. So I decided to cut it off and smooth it. I have seen someone else do this and it looked good
My effort wasn't so pretty but I will either fill the holes with weld and smooth it out or use filler (if I decide to spray paint instead of powder coat).
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Got busy properly masking up the engine and carb yesterday - in preparation for bead blasting. There are many people that are staunchly against this, and I understand why. I will begin first by blasting an area of it with soda as this is quite harmless. If that doesn't give the 'look' I am after, I will blast it with glass bead. Which I know looks good, it just somehow finds its way into every tiny open crack everywhere. Hence the extra care with making special plates, gasket paper and bolts to properly close off all openings. Fingers crossed...
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i really like what you are doing with that yamer hammer ! an aluminum lever arm for the front bake off any yamaha dirt bike would look better than stamped steel and weigh less !
and if you need more front brake there is a way to improve the single cam brake in fact it was std equipment on the 1981 yz250 this was right when all mfgs were switching to twin cam brake in the front 2-3 years later came the disc brake
yamaha even promoted the offset cam in ad literature it was not a huge improvement but something you may be able to do
what it was was either the actual cam had a short side or it was slighty off normal center , it was putting some more movement in the trailing shoe i think
of course a twin cam brake plate could be easily adopted as well
cheers keep up the great work !!!
and if you need more front brake there is a way to improve the single cam brake in fact it was std equipment on the 1981 yz250 this was right when all mfgs were switching to twin cam brake in the front 2-3 years later came the disc brake
yamaha even promoted the offset cam in ad literature it was not a huge improvement but something you may be able to do
what it was was either the actual cam had a short side or it was slighty off normal center , it was putting some more movement in the trailing shoe i think
of course a twin cam brake plate could be easily adopted as well
cheers keep up the great work !!!
I glass bead carbs all the time. I disassemble them completely first, and only do the bodies, bowls, caps, etc. You can achieve a really nice, semi-shiny factory like finish by using brand new - as in never used - coarse glass beads (about 200 micron). Yes, I get that the coarse size in counter intuitive. Glass beads shatter into small sharp shards very quickly and leave a very dull and coarse surface that traps contaminants and never looks clean. The coarse new beads leave a shiny smooth surface that stays clean looking and cleans up very well. I have done hundreds of carbs and never had a problem. I don't mask anything, but I make an effort to only blast the outside as I am only interested in the aesthetic result and clean the parts chemically afterward for function. Finish with hot soapy water and a brush and the normal comprehensive inspection you would do on any rebuild/clean. I did these old TZ carbs probably 20 years ago and they still look great - they have never had anything else done to them aside from getting an in-place blast of aerosol carb cleaner to remove fuel residue that accumulates.
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i have bead blasted carbs inside and out just masked masked the slide bore walls made all kinds of golf tee plugs etc
i found that just spraying on silicone lube or water repellet for clothes scotchgaurd is all thats needed for some parts to stop them from staining worked pretty well for the fins on 2 stroke jugs on my racebikes,no clearcoat just the silicone to seal... better to shed the heat as well
mobius this is what i read about the mechanics of glass beads,the beads are annealed glass,and they flex every time they impact this flexing and bouncing lika a rubber ball, is how they efficiently remove surface layers like paint,scale, rust without cutting or wering away the base metal
used with correct pressure they have many cycles of impact after whitch eventually the beads work harden, then they esplode
fresh beads work wonders to bring life to a slightly worn but still usable piston,it can bring up the diameter about .001'' and the surface holds lube well and it also is a good prep for the moly coating i bake on
back to it carry on
i found that just spraying on silicone lube or water repellet for clothes scotchgaurd is all thats needed for some parts to stop them from staining worked pretty well for the fins on 2 stroke jugs on my racebikes,no clearcoat just the silicone to seal... better to shed the heat as well
mobius this is what i read about the mechanics of glass beads,the beads are annealed glass,and they flex every time they impact this flexing and bouncing lika a rubber ball, is how they efficiently remove surface layers like paint,scale, rust without cutting or wering away the base metal
used with correct pressure they have many cycles of impact after whitch eventually the beads work harden, then they esplode
fresh beads work wonders to bring life to a slightly worn but still usable piston,it can bring up the diameter about .001'' and the surface holds lube well and it also is a good prep for the moly coating i bake on
back to it carry on
Thanks for the ideas on the brake xb. Do you have any literature/links about that offset cam for the drum brake? And have you seen anyone do the double cam adaptation? I would be very interested to see any solutions there and would def try something myself if it looked doable for me.
jpmobius said:
Thanks for tip and re-affirmation I was looking for to blast these things. Those carbs look fantastic - exactly the look I am after.
Good ideas from you too xb with the spray lube/water repellent. I have had that issue in the past where nicely blasted aluminium parts just collect dirt/oil etc and look dirty pretty quick again. Didn't know it could be used on pistons!
This week I am going to try and set up a kind of walk in blasting room in my workshop. I will build a wall with a door in one of the rooms, sealing off some area. Then I'll silicone seal all the edges and get some extraction going to the window that is right there. I think the freedom to be able to move around (especially with stuff like frames) will be great.
hold on ;D i dont use it on pistons for those i use KG coatings
it has the product ,gear coat ,(and manyu other coatings gunkote for one)which is the same as what kalgard used to sell \called piston kote
its a molyibdeum coating that you bake on any metal part,good stuff
back in the day these guys tole me about the stuff
'they were from my town and usa national number one in 1979 that is the kalgard sponsored tz750 chair right there
it has the product ,gear coat ,(and manyu other coatings gunkote for one)which is the same as what kalgard used to sell \called piston kote
its a molyibdeum coating that you bake on any metal part,good stuff
back in the day these guys tole me about the stuff
'they were from my town and usa national number one in 1979 that is the kalgard sponsored tz750 chair right there
xb33bsa said:
Gotcha. Yeah I meant I didn't know you could bead blast pistons and bring them back to life!
Got mail too! Hate it when the sender specifies signature required! Gotta fluff around at home waiting for the package to come. Much prefer getting a note in the post to say a package is waiting to be picked up at the local corner shop or whatever.
Anyway, it was the short cable samples I ordered. They look pretty nice! They are just missing some of the abrasion resistant sleeving I specified but other than that, seem spot on. They should look much better than the lanky ass stock ones.
Anyway, it was the short cable samples I ordered. They look pretty nice! They are just missing some of the abrasion resistant sleeving I specified but other than that, seem spot on. They should look much better than the lanky ass stock ones.
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The parts are printed with a 5% infill so there is as little plastic there as possible. The printer I have is the Printrbot Metal Plus and the filament is PLA. It took a long time to set the Printrbot up properly compared to a Makerbot (which I used at work) but now its dialed in its pretty reliable.
