Yamaha SC500 1974

[Rossvickicampbell]

Iain - there are 2 that I know of in WA - SC 500 motor in a YZB frame - pre 75 no worries - and boy do they go 

[Iain Cameron]

Ross the trouble I had was wanting to use a 75 mx frame . If by chance you find  YZb frame in your travels I know a very good home for it . Iain

[firko]

don't go there . I once said the mx400 frame was the same so why not add a SC500 . what a shit storm that turned out to be . not pre 75 as the frame was a 75 . not pre78 as the motor was 74 and all major parts had to be 75 to 78 . so they decided it was evo hence there is a pile of mx400 and sc500 still sitting in my shed . Iain 

Hmmmm......I can't see any reason whatsoever why it wouldn't be legal for pre 78 Iain. It'd take a brave and possibly very ill informed scrutineer to knock it back. The rolling frame is Pre '78 legal and while the motor is pre 75 legal it must go up to the next applicable division when fitted to the MX-B frame, that being pre 78. It's a no brainer....... Build it .

[Davey Crocket]

I have a YZ250B frame I could let go....it has matching cases as well....pm me if interested. The MX250/400B frames are close to a YZ250/360B frame but no cigar.

[Iain Cameron]

Hmmmm......I can't see any reason whatsoever why it wouldn't be legal for pre 78 Iain. It'd take a brave and possibly very ill informed scrutineer to knock it back. The rolling frame is Pre '78 legal and while the motor is pre 75 legal it must go up to the next applicable division when fitted to the MX-B frame, that being pre 78. It's a no brainer....... Build it .

Mark from memory I think it went to 7 or 8 pages and I got accused for trying to cheat into pre 75 , as the motor was not legal for pre78 cheating again . It all started with " if I built this what class would it fit into " type of question . 

[firko]

I don't recall that thread but if the cyber experts decided that it'd be cheating using it in pre 78, they're quite frankly wrong. Of course you can't use the MX-B frame in pre 75 but it's only natural that the whole package go directly to the next division which is pre 78. The rulebook says under the engine criteria that MX,YZ,DT,IT 175-250 built between 1975 and 1977. Those who told you that the SC500 can't be used for pre 78 would have been taking the '75-'77 clause literally but I'll stake my reputation that if you showed up with the SC500/MX-B hybrid you'd be welcomed into pre 78 with open arms. Some folks take things way too literally. If the authors of the pre '78 rules had followed the wording used in the other divisions, ie"must be produced before 31st December 1976" there wouldn't be any confusion.

[Freakshow]

i have a Sc500, mx360 or 250 for sale and probally as many parts.  i will be keeping my 500 parts as i have one built to go in the sidecar which i was building prior to the accident so i still plan on finishing it even if out of bloody spite !

[Freakshow]

Dont barstardize a YZB frame Davey for some other hybrid project.  there are plenty of frames out there anyway to practice frankenstining on , id rather put a YZ motor in there and save it.  PM what you want for it.

[Rossvickicampbell]

Freaky - glad you are back mate!  How are you travelling?

Now - what dates for next year?

[Freakshow]

23/24 August. cant be moved any more as week later is state titles and we wont get the timing people, week before we can get track people. so club has said that's the date.

[pancho]

Drums' N Fins..............a '74............I raced one in '74.....Dirt Track not MX..........raced this one at Australian Classic Dirt Track Titles, Temora in October.........watch this space in Classic Pre '75 in 2014......i'm getting braver with every SCHOONER !!!



Photo Courtesy of Bill MacPharlane

  GO! GO! Alvin!!

[Rossvickicampbell]

thanks Freaky

[FritzG]

When I worked for a local Yamaha shop in 77 a guy brought one in for a top end repair so we bored it to fit a new piston and put the top end back together, rode it around the shop to break it in for the guy. He brought it back a week later asking us if we were interested in taking it in on trade, he wanted a bike he could race without killing himself. The other mechanic purchased the bike from him and we used it to rip around the big field by the shop. Killer HP with a light switch power band but man would that thing throw roost. Scary fast, evil handling bike, both of us were racing at the time but were afraid to put it on the track.

I know what you mean about having a fondness for bikes nobody wants or have the reputation of being one of the worst...I just got done restoring a 83 KX 500. Now that I've got the head fixed (running the 84 head) the motor seems to pull very nice right off bottom and the back end works. Not to happy with the disc front end so I'm retrofitting a pair of 82 YZ 490 forks with the DLS front brake so I can bump down a class.

Enjoy the project!

Fritz
www.pnwvmx.org