#6

[Grumph]

What squish clearance have you finished up with ?

[dr gonzo]

F5 is correct. Look for the latest chassis possible with the best suspension and brakes. Weight is obviously an issue for a 50. If you are allowed and if you can find one, an old RS125 chassis is the ultimate. There have been huge advances in tyres and you will need to be able to fit new 17" tyres, and to fully utilize them you then need suspension and frame that is good enough, or at least closer than an MB50 chassis

I use aprilia rs50 fork, nsr 125 triple clamps, cone bearing, aprilia 50 supermoto wheels and brakes, bitubo rear shocks, and mtx rear swingarm, the honda mb frame.

I have must use the steel frame, because the local racing rule write it.

[F5 Dave]

Start another thread perhaps?

[speedpro]

It does sound interesting and a separate thread would allow others to provide advice without it getting lost in this one. Start out by posting a few photos and a description.

[speedpro]

I've buttoned up the motor, again. There's just a couple of cover plates and the like to go. It's so easy once all the parts have been sorted.
I have been looking at how to sort out the alternator. Overnight I thought about rewinding an old stator I have here in such a way that it would work with the new rotor. I had a careful look at how everything fitted and found that the new rotor is about 5mm larger ID than the old which will result in a larger gap than I'd want. This leaves me 2 choices - 1 install a late model stator or, 2 transfer the old rotor onto the newer hub. I'd prefer a new stator and have found one on AliExpress supposedly for a TTR250 which looks very close. It has a diagram with measurements which is useful. I've also found that despite what the wiring diagram shows, the stators I have for the engine are all delta configuration, not star.

[F5 Dave]

Have you done a genome sequence?

[speedpro]

The engine is back together and in the bike. I'm planning a small job on a water pipe and it will be done. I have gone ahead and ordered a stator I found that is close to, if not exactly, what is needed. I ordered valve guide seals at the same time. Funnily both were listed as being for TTR250 motorcycles.

[husaberg]

The engine is back together and in the bike. I'm planning a small job on a water pipe and it will be done. I have gone ahead and ordered a stator I found that is close to, if not exactly, what is needed. I ordered valve guide seals at the same time. Funnily both were listed as being for TTR250 motorcycles.

A very quick google suggests 3.5mm stem for FZR and 5.5mm for TTR250?






https://en.impex-jp.com/catalogs/mot...-s-101445.html
https://www.partzilla.com/product/ya...HX-12119-00-00
looking at the fiches here it seenm the 2kr ones are the same s yzf600
Yamaha Power Equipment EF1000IS CAMSHAFT/VALVE
Yamaha Power Equipment EF1000ISC CAMSHAFT/VALVE
Aftermarket Parts Engine Valve Train Valve Seals
Yamaha Motorcycle 1995 YZF600RGC Valve
Yamaha Motorcycle 1996 YZF600RHC Valve
Yamaha Motorcycle 1996 YZF600RH Valve
Yamaha Motorcycle 1999 YZFR7 - YZFR7L Valve
Yamaha Motorcycle 1995 YZF600RG Valve

the 3ln ones seem to only be 3LN
https://en.impex-jp.com/catalogs/mot...ha/fzr250.html
https://en.impex-jp.com/catalogs/mot...ve-100494.html
https://www.fowlersparts.co.uk/parts/view/3LN-12119-00

i can't even find a 3.5mm valve in the TKRJ list

What did you use Greg?

[Grumph]

Pretty sure I went through Don's stock until i found something that would do. He was Pitlane in ChCh and still has a heap of stock boxed when they did the post quake clearout. Pack of 10 of which i used 8 and don't even know if I can find what was left over. yamaha seals are a pain. What's listed for the 250 doesn't fit and the same goes for some 400 versions too.
I'll have a look tomorrow.

What stem size are the 750 and 1000's ?

Edit - these may even have been for Honda. I believe the 250/4's use 3.5mm stems.

[speedpro]

This is the listing: https://www.aliexpress.com/item/1005...60fd4c4ds4J7JV

16 valve stems in the set so not any TTR250 that was ever brought to NZ. Cheap as chips so worth having a look.

[speedpro]

10 days from order to being delivered.

[speedpro]

Oh well, it was still worth checking out. They fit 4mm stems so will be good for the 2KR version.

[speedpro]

I'm going to fit a Davies Craig water pump, an EBP-15, the same as on my scooter. Supposedly they are good for up to a 500cc bike. This will allow the removal of the Yamaha water pump and a tidier routing of water hoses which at the moment have a pipe exposed on the left side. I'll wire it up to the fuel pump circuit so that any time the fuel pump runs so does the water pump. Supposedly the local distributor has it in stock. I've also been working on all the little things need to go racing, which is taking longer than I thought it would.
With plenty of spare time I have been able to look at the ECU setup for when the turbo goes back on. I'm pretty sure I have it sorted out now. Once the main fuel map is sorted properly it will just be a matter of tuning another table so a certain % is added depending on boost and revs. Easy.
I haven't even looked yet but I expect there will be some sort of similar setup for the ignition.

I have noticed that Link have a default trigger setup for the engine in my car. I was thinking the other day how the car is a bit wimpy.

[speedpro]

3D printed a mounting flange for the electric water pump which I have decided to mount directly to the coolant port on the cylinder block. I need to make a proper alloy flange. I have wired a connector to ground and the fuel pump supply so whenever the fuel pump is on, which is when the engine is running, so will the water pump. I'm going to use the ECU to control the boost and have a solenoid bypass valve which I will wire to a spare aux output. I was going to use ignition 4 output which isn't being used and can be reconfigured as an aux output, but have decided to use a dedicated aux output channel. I imagine it would be quite handy being able to reconfigure unused ignition and fuel injection channels as aux outputs. I'm sticking to basics as much as possible but it's interesting what the possibilities are. I still need to figure out what's required to control the boost in the way of tables.

[speedpro]

I ordered an alternator stator(18 pole) for a newer FZR250. I'm now using a crank from a very late model FZR and the old stator does not work with the rotor that fits the crank. Supposedly the stator left the country of origin on 27 August but hasn't been logged at the next point. Seems that it may be some time. Batteries alone aren't going to work with the ignition, fuel pump and the yet to be installed electric water pump and boost control solenoid. If anybody has an 18 pole stator for a late model FZR250 I'd be very interested.