RD350 Track day bike

Message

John Huijben · #1 Post by **John Huijben** » Wed Apr 08, 2009 7:59 am

I've been reading regularly at this forum, so I figured i'd put my own RD350 down here.

It's a bike mainly just for track day's, but it is insured, and has lightning fitted to it, so I can have fun with it on the backroads out here as well.

The only original parts on the bike are the better part of the frame (subframe is homemade), and some of the engine parts.
Everything else is either homemade, from another motorbike or is modified.

Specifications:

Engine:
- Ported stock barrels with bigger reedcaged welded on them.
- Modified stock head with interchangable domes, with homemade domes designed for this engine
- Modified stock powervalve system, with the option to mount the servo directly on the valve, instead of using cables
- NSR125 reedvalves (0,4mm fiberglass plates)
- Mikuni TMX34 carburettors with foam air filters
- Ignitech programmable ignition and powervalve system with slightly lightened flywheel
- Modified stock engine cases
- Oil pump and kickstarted removed
- Homemade stainless steel exhausts, specifically designed for this engine (134mm thick belly's!)
- Homemade lightweight aluminium silencers
- Homemade manifolds.

Rolling part
- Modified stock RD350 frame (homemade subframe, various other modifications)
- Yamaha TZR125 tank
- 96' 125GP (Haruchika Aoki) carbonfibre seat
- Suzuki GSX-R 600 01-03 front fork
- Homemade wheelaxle
- Homemade steering head pin
- Suzuki GSX-R 600 01-03 brake calipers and pump
- Ducati 916 braking discs
- Yamaha SZR660 front and rear wheel (120tire in the front, 150 tire at the rear)
- Suzuki GSX-R 750 89' cockpit, GPT digital temperature gage
- Homemade clipons
- Homemade top triple tree
- Modified Yamaha SZR660 swingarm
- SZR660 rear brake
- Modified sprocket carrier
- Yamaha R6 99-02 rear suspension
- Homemade suspension linking system
- Homemade foodpegs, and gear shift mechanism.
- Homemade batterybox
- Homemade wiring loom

That's most of it I guess, some pictures:

Still with stock subframe here

It's rideable now, just have to tweak the carburettor setup a bit

I have made pictures of just about anything when building the bike, so if anyone wants to see a part in particular, I'll see what I can dig up

Total weight of the bike ready to ride, but without gas is 122 kilo's (269pounds)
I haven't had it dyno'd yet, but it easily pulls the front wheel of the tarmac in 2nd gear with 17/39 sprockets, without using the clutch or anything

Here is a small video of the bike, but it's runnig rich here, also mind the lousy sound at the end
http://members.home.nl/j.huijben/RD350% ... uijben.wmv

alexanderdraper · #2 Post by **alexanderdraper** » Wed Apr 08, 2009 10:45 am

Very Nice! I'd love to see more pics of the engine mods. particularly the grafted intake, and your home built exhaust.

Yamaha85 · #3 Post by **Yamaha85** » Wed Apr 08, 2009 11:26 am

That thing is pretty even with it's clothes on -
Nice job

Smoker · #4 Post by **Smoker** » Wed Apr 08, 2009 1:38 pm

Looks and sounds great!!

Please post up some detail pics so we can see more.

John Huijben · #5 Post by **John Huijben** » Wed Apr 08, 2009 6:16 pm

Pics of the intake and exhaust :

If anyone want some info on anything, or some other pictures, feel free to ask

#6 Post by **smurph** » Wed Apr 08, 2009 6:41 pm

Wow! Look at that shop! And the pipes are huge! Everything looks well done. Nice job!

You may want to think about bracing that frame before you get to far along. It will do wonders for it working with the rest of your suspension mods.

Steve

This old RZ · #7 Post by **This old RZ** » Wed Apr 08, 2009 9:17 pm

NICE JOB JOHN!

I love the fact that you got rid of the stock fuel tank, Its the first piece of bodywork that has to go on mine, Ive always hated the shape.

How did you get your workshop to look like a old brick country home??:smt102?? Must be those cool fabrication skills

ax-racing · #8 Post by **ax-racing** » Thu Apr 09, 2009 8:17 am

Wonderful job

intake modify is very interesting

John Huijben · #9 Post by **John Huijben** » Thu Apr 09, 2009 8:31 am

that's not my workshop, I'm very fortunate to be able to do some stuff at my work (after the boss's hours off course)

and for the reedvalves.
I recalculated the original membranes with blair formulas and found that they actually were made for 26mm carburattor's and nothing bigger, putting 34mm carburettors on the original reedvalves is a bit overkill.
So I digged around, and found some other reedvalves lying around.
These NSR125 reedvalves are made for 30 - 32mm carburettors, and wider RS / RGV 250 reedvalves are made for 34 - 36mm carburattors.
Unfortunatly RS / RGV 250 membranes are almost impossible to fit on the original barrels, because they are just to wide, even if you can get the reedvalves to fit, you woudn't have any space left for the coolant hose wich runs through the barrels.
Luckily the NSR125 reedvalves were just perfect.
Took me about a day to make them fit, and suit the carbs and the rest of the engine quite well

motoholic71 · #10 Post by **motoholic71** » Thu Apr 09, 2009 5:18 pm

Hey,very nice.And that aggressive look from those big pipes is a killer.very nice indeed.
Did you realy converted the head to changeable domes?Can we take a look at that if you have pictures,I'd like to see how you done that.
Great job,Thanks for sharing

Smoker · #11 Post by **Smoker** » Thu Apr 09, 2009 5:31 pm

The bike sounds awesome when you get on the pipes!!

John Huijben · #12 Post by **John Huijben** » Fri Apr 10, 2009 8:29 pm

Yeah, the really big pipes do work! I fitted brand new EBC clutch plates, with stronger springs, but the clutch can't handle the power when it starts to rev, it's close though, but it slips a bit. I just fitted even stronger springs than the EBC spring's, I'll check tomorrow if the clutch will hold up now.
The downside of the huge exhaust pipes is that there's not a lot of power beneath 6 - 7000 rpm, even with the powervalve working.
I haven't got the jetting quite right yet so maybe the lack of power at low rpm's has something to do with that, it's still running a bit rich (i'm running 240 main jets at the moment) so with low rpm's it runs like a 4stroke, but when the pipes starts to work it takes off like a rocket.
I'll try some smaller jets soon, see if that will help the engine run better at lower rpm's

Pictures of the modified original head:

The head design is pretty basic right now, I set the squish height at 0,85mm, and made sure that the squish band with, compression ratio and msv suited with the rest of the engine.
Works just fine, but maybe I'll try some different designs in the future

John Huijben · #13 Post by **John Huijben** » Fri Apr 10, 2009 8:37 pm

Found some more pictures regarding the engine

The manifolds have a stuffer attached to them, to make the transition between manifold and reedvalve smooth, like with a RGV250 engine

I can check the powervalve while running the engine

RuZty · #14 Post by **RuZty** » Sat Apr 11, 2009 9:18 am

John, I love your bike, you are very talented. I am in the process of building a naked RZ from parts I have around and was going to use the stock tank. It was posted elsewhere that yours is from a TZR (which model?) . I have a TZR125 (4DL?) plastic tank and a 3MA steel tank for another project that I never considered using up to that point. Before I start chopping more pieces off the frame, did you try fitting the tank to the RZ with the stock rear subframe? I don't really want to get into modifying that, but if it was a simple matter of cutting off the stock tank mount and making new mounting points I might do it.

John Huijben · #15 Post by **John Huijben** » Sat Apr 11, 2009 10:02 am

I used the TZR 4DL tank, but it doesn't work very well with the original subframe, the mounting point of the rear petcock will hit the right tube of the subframe.
It justs hits, so maybe you'll be able to modify it to make it fit.
I didn't needed the original subframe anyway, so I didn't even bother to look if I can modify anything but just cutted the whole subframe off.