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Yamaha R1-Z250YPVS 1990. My rolling project

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These were JDM only.
I bought it from an importer in the UK in April 2019 for £2k in need of a complete engine rebuild which I done myself except the crank rebuild and rebore work, replaced all the rubber bits except the radiator hoses they are in good condition and got it on the road in July 2019.
It only had 9k on the clock but had been stood for many years in Japan.

Total cost of buying the bike and fixing it in totally standard trim then registering was £2.8k. Since then I have bought other stuff and spent around another £800 ish but that was my choice.

After getting it on the road in standard trim it was time to start thinking about making an already fun bike even more hilariously fun bike for a 250.

  1. So heres what I have done so far.
  2. YSS suspension back and front. Soon to be fitted usd front end off of a SZR660
  3. Michelin power RS tyres
  4. Fork brace from Taiwan but most likely China, changed the chocolate bolts for stainless ones apart from that its well made and works well.
  5. Martin Johnson chambers (bloke in Devon makes them) with TYGA cans.
  6. Changed out the restrictive 26mm TM carbs for two 28mm TM carbs from DTR 125's with the added bonus of the dt carbs having air screws. the idle adjuster on the right hand carb needed moving from the left side of the carb to the right side which was easy as Yamaha had left a threaded blind hole so all that was needed was to drill through and fit the iidle screw and blank off the other one. The air screw however cant be moved but a longer thin screw driver does the job.
  7. Polished the cylinder head domes
  8. Cleaned all the rough casting lumps and bumps from the transfer ports and smoothed them and knife edged the web.
  9. Removed the hump in the exhaust ports and removed casting marks then lightly polished the ports.
  10. Removed the snorkel or pig nose from the airbox.
  11. Barend mirrors fitted, they look a shit load better than stock and suit the bike well I think.
  12. Carbon reeds.
  13. Removed the KMH speedo and fitted an MPH one from a TZR125 only reads up to 100mph (yeah mate it goes off the clock 🙂 ) though it was a straight fit in the case. Will now be fitting the speedo from the SZR660 as it reads up to 120mph.
  14. Fitted the SZR660 rear wheel as it allows a 150 section tyre rather than a 140 section tyre. The wheel is a straight fit no messing with spacers or anything and the R1Z sprocket hub is a straight fit to the SZR wheel. 

The carb jetting is 260 main, 35 pilot and needle clip is central. Will get it on the rolling road one day to see actual rear wheel bhp but stock they are 45bhp at the crank

The result is a bike that handles very very well around the bends and goes very very well in a straight line too.

I decided not to have the bike re painted as I like the look of its crusty appearance and the small dent it has in the tank gives it character and is part of it's history.
The rusty bits I treated with Kurust to neutralise it. I had to paint the front wheel as the original finish had surface corrosion from when it was standing for many years and did look horrible.

A few random pictures of the work I have done to it.







Plug burn colour.jpg

Polished domes.jpg


20210321_111232 (2).jpg

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12 hours ago, finnerz89 said:

A programmable ignition would set it off now 👍

Yeah I was thinking of zeeltronic but they are a bit pricey once you take into account set up as there are no base line ignition maps with it, so I think a rolling road will be needed to lessen the chance of doing some damage. Some people reckon around 5bhp can be gained.


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36 minutes ago, Alfiestorm said:

Yeah I was thinking of zeeltronic but they are a bit pricey once you take into account set up as there are no base line ignition maps with it, so I think a rolling road will be needed to lessen the chance of doing some damage. Some people reckon around 5bhp can be gained.


I thought they did come with a base map?

There's ignitech as well, wouldn't be plug n play but the wiring wouldn't be hard.

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They do, with the ig set to the base line of the bike your buying it for. On a tdr most people are just buying the pv controler more than ig because lets be honest, most bikes with a tax disk need little more than a tweak at high rpm maybe.

Its the pv that is set conservative for rideability etc. We all want a bigger punch on the ride and if you can live with more brutal characteristics you open the pv earlier and faster. One of zeeltronic bloggers has done it, on you tube somewhere starts opening at 4500 rpm or so and wide open at 7 or so, (allowing for motor cycle time) will have the motor going at its hardest. Wont be the most civilised ride as you will be always on pipe, but it is  a 2 stroke though right.

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  • 3 weeks later...
  • 3 weeks later...

After a bit of fecking about with the bottom bearing, problem was the R1Z bottom bearing is shorter than the SZR one, so with the new r1z bearing fitted to the bottom yoke the yoke rubbed on the frame, was an easy fix but did require another new bearing. I made a 5mm spacer made out of a moped clutch nut to sit under the new bearing.

Also done the lock stops which was a simple drill tap and nut and bolt job,basic but does the job superbly. 


Lock stops.jpg

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  • 2 weeks later...
Handle bar arrangement has changed from the ace bar idea after a mock up. It just did not suite the bike. So i have a pair of SRAD 750 clip-ons on the way after being sent the wrong one first time round. They have a one inch rise so maybe the perfect bars maybe.
Meantime i now have matching wheels, I was going to take the rim tape off the front wheel but then found out it is lacquered over so had to fit the other SZR rear wheel. Fitted my original power RS tyres. Painted the chain guard gold to match the gold highlights on the forks and bottom yoke.

Gold chain guard.jpg

Wheels and stripes.jpg

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Went out for a test ride yesterday and it all works very well.

The front brakes are fantastic and my only criticism is there is not enough lever travel for my liking which I will sort out.

A few adjustments needed to re-route throttle cable as the revs rise a bit when the bars are turned full lock to the right, as well as the mudguard going black when the weather warms up the brake calipers will also be painted black.






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Looking good...

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  • 2 months later...
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  • 6 months later...

It has been a while since I popped in here and in the search for more power and some research I have fitted the tope end  from a TZR250 2XT model. 

The 2XT has plated bores instead of steel liners so are lighter and they have auxiliary exhaust ports and wider power valves fr more power so over the last week I have been busy prepping the 2XT top end ready to fit on my engine, which I completed yesterday. I have been out on it today in the one dry spell we had and gave it a good runabout an checking the plugs which looked happy and the bike felt happy too, went into the fun zone a few times and what a difference the 2xt top end has made. It has gone from a mad hooligan bike into a bonkers hooligan in the fun zone. It will be off to the dyno very soon for final set up and the all important back wheel power output readings.


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