News:

Mat Oxley 1986 IOM TT


click above to read more about Mat.

Main Menu

YSR50/80 Build

Started by Diablo007, March 06, 2021, 03:18:04 AM

Previous topic - Next topic

0 Members and 1 Guest are viewing this topic.

Diablo007

Got back a YSR50/80 project I started 25 years ago and sold about 15 years ago.  I still hadn't been built or started.  I now have the engine running.  It has a Team Calamari 24mm flat slide w/o oil injection.  I would like to add oil injection so I don't have to worry about premix.  The easiest way I can think is to add a carb spacer with an oil injection port.  Has anyone done this?
2 stroke junkie:
Too many motorcycles to list.  The highlights:
1973 Yamaha RD350 Cafe Racer project; 1983 Suzuki RG250 YammaGamma project; 1988 Yamaha YSR50/80 project; 1984 Yamaha RZ350; 1984 Yamaha RZ500

85RZwade

No, but I have drilled a hole in a carburetor and epoxied a hose barb in it. Works fine.
I post waayyy too much

m in sc

spacer works, ive done it.

moving to 100 cc forum just fyi.


excellent project, looking forward to it.

DesmoDrew


Diablo007

I know that drilling and press fitting an injection nozzle is an option, but with this carb I'm not certain it's a good idea as there doesn't seem to be a good place.  See pic.

'M in SC'; seems the YSR uses the same intake gasket as the RD, did you use the RD spacer?  What were the dimensions if you can remember.  I have a friend with a CNC mill that would be able to make one for me.

Also attached is a pic of the YSR when I saved it.
2 stroke junkie:
Too many motorcycles to list.  The highlights:
1973 Yamaha RD350 Cafe Racer project; 1983 Suzuki RG250 YammaGamma project; 1988 Yamaha YSR50/80 project; 1984 Yamaha RZ350; 1984 Yamaha RZ500

m in sc

I HAD AN RX50, SAME gasket. Yes, i think i played with a spacer i had laying around.   

Diablo007

Thanks 'm'

Since I'm having the spacer custom made any idea on the thickness?  Should I stick with 9mm?  Any advantages to going thicker or thinner?  We plan to start with 3/8" stock, roughly 9.525mm.

@ Desmodrew; thanks for the link, I've used RC fuel line in the past for oil line, for some reason using an RC fuel line fitting hadn't crossed my mind.  I plan on using this instead of press fitting.
2 stroke junkie:
Too many motorcycles to list.  The highlights:
1973 Yamaha RD350 Cafe Racer project; 1983 Suzuki RG250 YammaGamma project; 1988 Yamaha YSR50/80 project; 1984 Yamaha RZ350; 1984 Yamaha RZ500

m in sc

6-7mm is what i would aim for.

Diablo007

Thanks 'm';

I was thinking the spacer would go between the carb and reed block, am I correct in that?  If I'm right that makes better mid-range and top end.  The motorcycle is for my wife and for street use.

Also, why between 6 and 7 mm?

Thanks,
D
2 stroke junkie:
Too many motorcycles to list.  The highlights:
1973 Yamaha RD350 Cafe Racer project; 1983 Suzuki RG250 YammaGamma project; 1988 Yamaha YSR50/80 project; 1984 Yamaha RZ350; 1984 Yamaha RZ500

m in sc

reed and cyl, actually.

Diablo007

Thanks, that actually makes more sense.  I was thinking placing it there wouldn't allow proper oil flow, but since you've done it it does.

That leaves the question, why 6 - 7mm, vs 9mm.  the displacement?
2 stroke junkie:
Too many motorcycles to list.  The highlights:
1973 Yamaha RD350 Cafe Racer project; 1983 Suzuki RG250 YammaGamma project; 1988 Yamaha YSR50/80 project; 1984 Yamaha RZ350; 1984 Yamaha RZ500

m in sc

it affects crankcase volume and resonance. you really need to run and check, BUT, its always better to err on the side of thinner/less volume

Diablo007

@m

Good to know, thanks.

Funning with you but...there was this parts DT100A tucked away in the shop, pulled it out and the engine runs.  If I put the engine in the YSR does the project get moved back to the 'big boys' page.

In all seriousness though.  Since DT100 parts are more readily available and YSR cranks are known to fail, I'm seriously considering swapping for the DT100 engine.  Anyone out there that's done this?  Any insight?
2 stroke junkie:
Too many motorcycles to list.  The highlights:
1973 Yamaha RD350 Cafe Racer project; 1983 Suzuki RG250 YammaGamma project; 1988 Yamaha YSR50/80 project; 1984 Yamaha RZ350; 1984 Yamaha RZ500

Dvsrd

I would be more tempted to restore that DT,  and look for an YZ80 or 85 engine for the YSR.
Which in fact would make it an YZR  :metal:
Or maybe a DT125 LC/Ypvs engine can be shoehorned into the YSR? Those are both pretty powerful, and sivilized as well. My son had a KTM125 Sting supermotard. Little brother of the KTM Duke 1st gen. Around 25 hp, would run an indicated 145 km/h (90 mph) on a flat road ,with me sitting upright in a flapping Cordura jacket! Surely that engine would easily push an YSR past 100 mph.....

Djg8493

Not yet but I do have a similar project coming up at some point.  My YSR stock engine still runs decent but I picked up a MX 100 to swap in at some point.  Looking for the stater etc. for lighting but from the engine should not be too hard to mount.  From what it looks like and what I read you just need to make new hardware for the front mounts but they do line up and trim the rear mounts abit.  Hardest part will be the exhaust so not too bad. 
1970 R5, 1975 Rd350, 1978 GT80, 1979 KZ400, 1988 Ysr50, 1990 GSXR750, 2006 WR450 SM, 2006 R6