Dave’s Custom 650


It’s as solid as a rock

Describe Your XS650: Year: 1977
The plastic half of the rear mudguard was, until recently, the only part of this ’77 model not modified. However, I had to cut a piece out of it to clear the oil lines and the remote filter, which lives just behind the swing arm pivot. So now, I can say that every single part of the bike has had work of some kind done to it.

The frame is basically stock, but clean up with several brackets removed and others welded on. The front wheel is a rear wheel off a ’79 Special, disc is off a TX with a custom centre. Calliper is from Performance Machine. Forks are from a 1987 Suzuki GSXR-750, converted to cartridge, on custom trees designed by me. Rear wheel is off an ’81 Special, in a swing arm made by me. It’s asymmetrical to accommodate a belt drive. Both mudguards were made by me in ‘glass. The rear is a copy of a Special, and the front is two of them, cut short and joined together. It has roller bearings in the swing-arm and in the steering head.


Motor is 750cc, with JE pistons and Carrillo rods, both designed by me. Head is ported, with intakes extended. Carbs are Mikuni 36mm flatslides. Aside from the element itself, the air filter housing and intake trumpets were made by me. One filter does both carbs. Valves are stainless steel, 1mm oversize. Rockers are modified to take Porsche tappets. Combustion chambers, exhaust ports, valve heads, piston crowns and skirts all coated with HPC. Crank is rephased to 90 degrees, balanced, and completely polished.

Cam is likewise re-phased, is Megacycle 250-30 profile, and modified to has been modified to be belt driven on one end, and have 2 Boyer-Bransden ignitions on the other end. All hardware for belt drive and ignitions desined by me. All flat pieces made by me, all round pieces made by a friend with a lathe. Clutch has Barnett springs and 8 of their plates, as well as modified shock absorber with buffer blocks replacing every second spring. Lube system has a high volume oil pump. Cooler and all plumbing is Earl\’s and as mentioned earlier, has a remote filter made by me, with a spin-on element from a car.


Electrical system completely replaced with permanent-magnet alternator from RZ-250, reg/rec from Boyer-Bransden, chrome switches from Mike’s XS, lights are custom, and wiring done from scratch.

All brackets, saddle bag frames, number plate frame, luggage rack and sissy bar made by me. Belt final drive designed by me.


Paint was candy apple red but redone recently by Bad Image to my vague (skulls and flames over black) suggestions. In last pic, I’m part-way through making new pipes. They’ll be chromed and, like the last set, ceramic coated on the inside.

Bike is almost maintenence free. I don’t have to clean or adjust chain, clean crap off rear end of bike, check or replace alternator brushes, adjust tappets, adjust points, or use tools and go into motor to change oil filter. I can check cam drive tension just by sight and replace belt just by losening idler pulley (although I never expect to do it). About all I do is check tyre pressures and change oil every once in a while. Most time consuming job is polishing.


Bike goes like a missile and because it’s a 90, will rev off the dial and does not vibrate at all. It’s as solid as a rock on the road and an absolute pleasure to ride.


Thanks David Rayner

This XS650 is absolutely amazing! What you guys think? leave a comment below.. And, if you’re sitting on some XS650 pics send them in and share with the world….


  1. Jon M says:

    I have checked out your website and you damn sure have some mechanical ability. What a piece of work!!! The pic of the engine is like a metal sculpture. Do you sell a belt final drive for xs650’s? I know there was someone looking for info on a final belt drive a while back.

  2. Jon M says:

    Why am I the only one leaving a comment on this xs650? It’s crazy!

  3. hooligan mike says:

    Yeah your right there should be more comments on this bike!
    Ne way here is my question im a bobber guy and would like to know if you would like to talk about building me a engine for my next project??

  4. Steve says:

    Very nice , a ton of thought and work !!

  5. Billy says:

    Some super design work

  6. Ron says:

    Simply amazing, great job, one of, if not the best I have seen.

  7. gino says:

    Yes, i am wondering the same thing, Do you sell a belt final drive for xs650’s?

  8. David Rayner says:

    Thanks for the kind words about my bike. Jon M, there are 2 possible reasons why it didn’t get more comments – the first is that one must scroll through 30+ pages to see it. I found it during a quiet time at work and for as much as I love Yamaha 650s, after 20 pages I could have easily stopped. I know that the more people who send in pics of their bikes, the more pages there’ll be and that’s good but the further in one’s bike appears, the less it will be seen. The other reason is that maybe people aren’t that impressed by it.

    My web site no longer exists but if you want more info on the belt drive or anything else about my bike, email me at dave650@bigpond.net.au or david.rayner@riotinto.com There are now at least 2 more 650s with belt drives that I know of.
    David Rayner.

  9. Gerry says:

    WOW! i saw the belt drive then frantically started looking for a blower…hehe. Ya know whats going on don’t ya? Peeps are intimidated. You can spin a wrench on my bike any time.

  10. Merc says:

    I am certainly impressed by your bike, not really the style I’m into, but definitely an amazing attention to detail. I am brand new to this scene and hoping to learn as much as I can by checking out any ride I come across. Thanks for sharing the pics and info.

  11. Fabbastard says:

    Ya that belt drive is an interesting set up.

  12. ghostryder says:

    the most interesting part of this bike to me is the 90 degrees. would love to hear more about it and what improvements, if any were gained. thats a huge amount of labor. at least my humble opinion.