What's going on with this ?

[mainline]

Maybe GMC could make you a chrome swingarm?

[GMC]

Maybe GMC could make you a chrome swingarm?

Would he want it to suit just one model do you think or would he want it designed from several different models to match the bike??

[YZ250H]

 

[vandy010]

Edit : having looked at some parts diagrams, I reckon DT400D is very close to the mark, right down to the bushes (only) in the swingarm pivot.
Even the shock looks pretty close    Maybe someone has grafted the DT400D onto the back of this beast    Brake backing plate matches the swingarm also - something else to locate 

or did they just put a YZ tank onto a Monoshock DT and you fell hook line and sinker?
just a thought.

[YZ250H]

Frame and motor numbers are 509- .......   

[marc.com]

Maybe GMC could make you a chrome swingarm?

Just chrome what you have, and then slip it into an XL250 chassis  they fit like a glove

[Ted]

Buy a canoe...no moving parts

[KB171]

Is this what your sposed to have Tony?

[mainline]

Is this what your sposed to have Tony?

except his has the optional girder forks from a 1937 Excelsior

[YZ250H]

Yeah, that's the one KB.  The numbers on the frame and the motor are correct.  i have the forks with the Tacho and Speedo.   I've even got the bars with the high cross bar.

Looks like someone has done a dodgy with the swingarm and shock .  I've got  a shock on the way (thanks for finding it).

Need a swingarm and a brake backing plate.  Or I could just use what I have and clobber all the train spotters that point out that the swingarm and backing plate is wrong 

[GMC]

I think this is the backing plate, bloody hard to tell sometimes with the official part names

Part # = 483-25321-00-98
Part Description = PLATE,BRAKE SHOE
Model Count = 9
IT400C 1976 400 IT400 Dual-Purpose
MX250B 1975 250 MX250 Off-Road
MX400B 1975 400 MX400 Off-Road
TT500C 1976 500 TT500 Off-Road
TT500D 1977 500 TT500 Off-Road
YZ250B 1975 250 YZ250 Competition Motocross
YZ250C 1976 250 YZ250 Competition Motocross
YZ360B 1975 360 YZ360 Competition Motocross
YZ400C 1976 400 YZ400 Competition Motocross


And the rear hub if you need it

Part # = 483-25311-13-98
Part Description = HUB,REAR
Model Count = 22
IT250F 1979 250 IT250 Dual-Purpose
IT250G 1980 250 IT250 Dual-Purpose
IT400C 1976 400 IT400 Dual-Purpose
IT400F 1979 400 IT400 Dual-Purpose
IT425G 1980 425 IT425 Dual-Purpose
MX250B 1975 250 MX250 Off-Road
MX400B 1975 400 MX400 Off-Road
TT500C 1976 500 TT500 Off-Road
TT500D 1977 500 TT500 Off-Road
TT500F 1979 500 TT500 Off-Road
TT500G 1980 500 TT500 Off-Road
TT500H 1981 500 TT500 Off-Road
YZ250A 1974 250 YZ250 Competition Motocross
YZ250C 1976 250 YZ250 Competition Motocross
YZ250D 1977 250 YZ250 Competition Motocross
YZ250E 1978 250 YZ250 Competition Motocross
YZ250F 1979 250 YZ250 Competition Motocross
YZ360A 1974 360 YZ360 Competition Motocross
YZ400C 1976 400 YZ400 Competition Motocross
YZ400D 1977 400 YZ400 Competition Motocross
YZ400E 1978 400 YZ400 Competition Motocross
YZ400F 1979 400 YZ400 Competition Motocross



This should be the swingarm
Part # = 509-22110-00-33
Part Description = REAR ARM COMPLETE YAMAHA BLACK
Model Count = 3
IT400C 1976 400 IT400 Dual-Purpose
YZ250C 1976 250 YZ250 Competition Motocross
YZ400C 1976 400 YZ400 Competition Motocross

[vandy010]

Tony,
if you've got a DT250D rear wheel, they're a pretty sweet thing and still pre~78 legal and if you weld a tab on the swingarm to take the "slipper" style backing plate (if thats how it is) then i'd be going with that.
much easier to remove the rear wheel being a bonus
but if it's the "cush drive" DT400 unit, then toss it.

[YZ250H]

Thanks guys.  My Zedder died along with my old computer and I can't find the email that unlocks it.  Must look again as I find it very handy 

The swingarm and backing plate are slipper style, so maybe that is actually an improvement  .  As you say Mick it would still be pre 78 legal.  Not sure how anal I want to be with the whole YZ thing.  Maybe I just wack it together as is and take my time looking for the correct swingarm.

I will have to take some photos on the week-end of the hub and post them up.  From memory I don't think it is a cush drive jobbie.  Has three holes drilled between each sprocket bolt.  Maybe that will help identify it 

[Nathan S]

I've got a couple of 483 hubs if you want one. They've been close to hitting Ebay for about a month now.

[YZ250H]

Thanks Nathan,

I will see what I've got first and get back to you