1978 SR500,"The Petite Bastard"

Yep it's another bastard. Unfortunately this one has been off the road for nearly 3 years. I thought i'd throw up a build thread for this bike even though it'll be slow going. Right now as i'm dealing with the Bastard Tourer she won't be getting a lot done. Once the Tourer is up and running though i'll get back into this bike. That said there's things that may get done from time to time, hence why i'm putting it up now.
Here's a couple of photos of when i was first getting around on her.



The shopping and repair/replace list includes

Engine gets a complete rebuild top to bottom with high comp piston, cam, porting, forged conrod and a bunch of other fun bits. It'll cost a bit, hence the long build time. Can't help being unemployed : Bottom end will be checked through and should be fairly good as the bike's only 50 thousand kms old. New seals and o rings throughout and a stainless bolt kit. Engine colour undecided. Will be running a big filter (not a pissy little one, gonna need the airflow) on a velocity stack through a Mikuni VM38 with increased length intake tract for bottom end between carb and head.

The frame has had most of the grinding done, there's one or two more tabs to clean up but for the most part it's ready to start prepping for paint, except i don't know what colour i'm going for... I still need to cut out the gussets in the airbox part of the frame and replace them with matching ones. Not sure of the design yet, i'l get to that.

For the suspension up front i'd like to fit a whole front end off something else with uppy downy forks and big bastard brakes. Rear swingarm i'd like to convert an alloy one to suit. I'd like to keep the twin shock rear on it though. All this aside i loved riding it as it was and i may still decide to keep the stock front and rear. It handles nicely, why mess with it? Why not hey?

Colour, dunno, but it will have brush work as i love pinstriping.

Tank is GSX250. I butchered the one i have with a gasless mig so i need to grab another one and take it up to a mate's in the near future for proper welding instead of toy welding. Seat will be pretty much the same as on that orange Motofiaccone bike. I think it was an oiler of some sort.

Lighting i'd like to keep hidden and that includes the headlights. I don't know how i'll do that one but brake, tail and turn signals should be easy enough.

I've considered an imola fairing and also something like on the racing Bultaco Metralla but i haven't decided yet.

In fact my indecision is one of the big things holding me up.

Here's some progress photos to date.
Home made swing arm pivot pulling trick.







And here's a photochop i did a while back of Deus Ex Machina's Greivous angel with a tank swap. My bike will be a lot different but you get the general idea.


Well, next update will probably be this time next year unless things change a little. I'm sure once i get off the breadline it'll be full steam ahead.

Looking good staffy. I'd love to get my hands on one of those, they seem to be rare here in Ontario Canada. I can't get over how reliabe those thumpers are. My wife/spouse/common-law's 250 just takes the abuse and keeps going. Hell here first sr250 was ran over at my work by an asinine truck driver. Totaled. Picked it up, but the gas tank back on, key in ignition and she started up. Awesome. the rear fender was tacoed. Now it'll be my track bike. Insurance paid for another.

Keep it coming.

Thanks Jay. They're getting harder to find here too. In fact prices here in aus have gone through the roof. If i put it back to original tidy stock form i could get $5000 minimum for it. It seems to be the trend with a lot of jap bikes of the era now. CB fours in good nick $3-4000 minimum, XS650's are getting $5000 or more. I got in too late!! This is the bike i learnt to ride on so i won't ever sell it. If you can finde an SR500, grab it with both hands. Loads of torque and great fun all round.

I've got my 1978 SR500 project bike waiting in the wings for me... just biding my time I got lucky on the purchase and grabbed it. Might not get around to it anytime soon - I think I even have a build thread I started last year for it! Maybe this winter. This summer/fall project is the Honda CA95. I think I've convinced my wife to upgrade her scooter license to a full motorcycle level so she can ride something bigger than 49cc.

If you find that thread Tim send me a link so i can click the notifications thinger (even though it actually doesn't work... grrr) and watch it happen. I'm the same mate in the sense that i'll probably pick something else up and this'll hang back as a low priority. I'm getting such a ribbing over on the SR500 forum about this bike "why don't you just put it back together and stop wasting your time on that CX"
Is she gonna be riding the CA95 then?

That'll be nice!

very cool staffy. ill be watching to see how this turns out for sure

Tim said:

I've got my 1978 SR500 project bike waiting in the wings for me... just biding my time I got lucky on the purchase and grabbed it. Might not get around to it anytime soon - I think I even have a build thread I started last year for it! Maybe this winter. This summer/fall project is the Honda CA95. I think I've convinced my wife to upgrade her scooter license to a full motorcycle level so she can ride something bigger than 49cc.

Click to expand...

Been looking forward to your build, but not really expecting anything anytime soon. As for your wife going bigger, by the end of the riding season last year mine was mulling a larger bike, but still wants something vintage so I'm on the hunt for a 350 or 400. Her current one the sr250. Her quote today while looking for boots "I'm not out to look like someone's backseat eye candy" lol

Staffy, up here those xs650 took a major jump the last couple of years as well.

A mates got an XS650 for sale right now with a $7000 price tag. It's worth every cent too but i could of bought the same bike for $2000 back when i bought the SR!

Hmmm, well the interest in this thread without me actually doing anything has kinda given me the impetus to start shuffling things about and getting into it. So as soon as i find work again i'll start collecting the various engine bits and get into it. In the meantime i'm gonna get the frame finished off, tidy up a bit, clean the engine and build a table to work on the bike. That's all cheap stuff.

Had a beer or two today at a friends and we got talking about the spare turbine setup he has for a CX500 turbo and the conversation went onto the subject of the SR500 and the possibility of combining the two. Just thoughts at this stage. Most likely I won't do it, but the next thought is, why not? Could be fun.

Very cool Staffy. Ill be watchin for sure! I love those SR's.

Heck yeah Staffy, I'll be watchin this one too.

Shhh, steady on guys, nothin confirmed yet, just thoughts. My biggest worry is pushing too much into an engine which is for all intents and purposes difficult to get parts for over here. Majority of stuff is available but if i cracked a case or something, that would be it i think. The boost would be quite low if this got done. There's also a part of me that looks at this bike with puppy dog eyes and doesn't want to butcher it too much as well.