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Bill Bune in Minnesota is who did mine. I believe he is one of the "go to" guys fir this.

I second Bill Bune. He is THE Suzuki triple crank rebuilder. I had good luck with him back when I rebuilt my GT380.

It's very difficult to tell from pictures like that.

Things to check:
- Put the pistons at the bottom of the stroke and make sure that the crown of the piston is level with the bottom of the exhaust port.
- Use a degree wheel to measure the port timings and see what RPM you're making power.
- Measure the the exhaust port width. It should be no more than 67% of the bore diameter. You will need to remove the cylinder and make a port map to verify this.
- While you're in there, make sure all of the ports are adequately chamfered where they meet the cylinder so your rings don't snag.

From what I can see, it doesn't look overly terrible. I've seen some genuinely bad porting that still ran fine. As long as the above items check out, I'd probably run them. Maybe clean them up a bit first if you're worried about it.

Any idea what the intake ports look like?

Did anyone manage to save any of the technical info regarding the Ninja 250 swap? I guess that's one of the threads that didn't get archived.

I'm about 3/4 of the way through a swap on my RD250 and seem to have lost the spacer drawings when I moved my shop. I still need to make the steering neck spacer. At the moment, I just have a piece of pipe in there so I can roll the bike around.

I don't need ALL of this info since most of it is already done on my bike, but for the sake of continuity, I want to document the following info:
- How much to cut off the swing arm
- Drawings for rear lower shock spacers to fit the stock kickstand bracket
- Drawing for rear upper shock mount bracket
- Drawing for steering neck spacer
- Lower shock mount bolt size
- Upper shock mount bolt size
- Steering stem bearing size

Here is the RD250 that I've nicknamed Project Tetanus:




This bike will be disassembled, cleaned up, de-tabbed, and painted once everything is welded and in place.

Anyway, I was able to come up with a little bit of the above requested info, but I want to confirm it's correct as this is mostly from memory:
- Cut approximately .25" off each side of ninja swing arm pivot tube (measure frame to verify, make sure sprockets line up, tap bearings in and tape them off first!)
- Upper bracket started life as a 1.5" x 2.5" x .120" wall x 12" long piece of rectangular tube stock and a 12" long piece of 1" x .120" wall round DOM tubing. I think I needed about 6" of the rectangular stock and about 8" of the DOM tubing
- Lower shock mount bolt size: m12 x 140mm
- Upper shock mount bolt size: m12 x 45mm
- Steering stem bearings 30mm x 48mm x 12mm (upper AND lower?)

I may have the drawings saved on my old desktop, but I haven't had time to sift through all of my old files yet. If somebody has them, please post them. Also, feel free to correct me if any of the above info is incorrect.

I'm also interested in seeing what people have come up with for rear sets and which aftermarket pipes will fit around the bottom shock mount. I seem to remember a lot of people reusing the ninja rear sets, but mine were in pretty bad shape.

Edit: I'd also like to hear what people are using for sprockets as the Ninja and RD use different chain sizes.

When it comes to suspension, the sky is the limit and your budgets and performance requirements will pretty much determine the best option for you.

I've had really good luck with those really cheap "RFY" adjustable shocks. They can be had for about $50-60/set and are a major upgrade over stock shocks. A lot of people rebuild them with fresh seals and a known weight oil to improve the damping. There are a few tutorials kicking around on how to do it. They're pretty much a bottom of the barrel budget option but seems to be working well for the street riding I do. They held up well on my cross country trip and my bike was loaded down pretty heavily with tools/parts/supplies. Well worth it for the money, but not necessarily the best quality out of the box.

I don't have any pictures of my cross country bike at the moment, but here is a photo of my R5 with the RFY shocks:


If you're looking to spend a bit more for quality and retain more of a stock appearance, Hagon would probably be my choice for name brand shocks. And if you want to spend big money and get a custom made shock with your specified spring rate, there's always Ohlins... though I've never been able to justify over $700 on a pair of motorcycle shocks!

Note that stock shock length is 325mm, so you'll probably want to stick to that or you'll be changing your suspension geometry. Also make sure that you get shocks with the correct ends as there are a few different types.

There's also suspension swaps from other bikes (notably the ninja 250), but I assume that that topic is a bit out of the scope of your question.

The reflector holes in the steering neck brace plate says that it started life as a road legal frame, not a TZ. Definitely a parts bin bike. Cool project, but not for $8,500.