Kiwi Biker forums - Blogs - Stink Racing by Skunk https://www.kiwibiker.co.nz/forums/blog.php/2010-Stink-Racing Kiwi Biker - New Zealand motorcycle community en Thu, 30 Apr 2026 16:06:46 GMT vBulletin 20 https://www.kiwibiker.co.nz/forums/images/BP-Brown/misc/rss.jpg Kiwi Biker forums - Blogs - Stink Racing by Skunk https://www.kiwibiker.co.nz/forums/blog.php/2010-Stink-Racing Update https://www.kiwibiker.co.nz/forums/entry.php/3942-Update Tue, 24 Jun 2014 10:32:55 GMT The ZXRD400 has been to Ruapuna, Taupo and Manfeild with various 'success' values.

Ruapuna was its first Race meeting and a lot was done on the Friday test day to get it working. Much thanks to Bert, Crazyman and the other GPR boys and Leigh for the running around. Chenged the brakes, forks settings and other stuff. Overall it seemed to go OK.

Taupo was the next Race meeting. This wasn't sp good as the slower corners showed a serious part throttle issue. Also the bike vibrated quite a few bits into a broken state. Not unexpected...

Manfeild was the next outing after some mods and 6 hours on a dyno. Power and smoothness both improved greatly. Unfortunately a head gasket decided it had had enough.

So, 'O'-ringing the head and a couple of other bits to be done and we will be on the track again.
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]]> Skunk https://www.kiwibiker.co.nz/forums/entry.php/3942-Update It runs https://www.kiwibiker.co.nz/forums/entry.php/2830-It-runs Sun, 13 Oct 2013 06:48:22 GMT Successful day testing the ZXRD400 at Manfeild yesterday. I pushed it up pit lane a lot which lead people to believe I had problems but I was doing plug chops and it didn't roll far enough.
It sorta, almost, nearly nipped once as it wasn't right when running off the main. Stopped once due to an electrical fault that cut power to the Ignitech. Had so help sorting that so it didn't happen again.
We ended up changing main jets, pilot jets (thanks Murray Cross for going home and getting a selection) and adjusting the air screw. Moved the needles down and up again. The day ended when the stinger parted company with the chamber. Never got to play with the ignition curve so there is more to be had.
Rear shock needs replacing (got one ready), and it needs some front brakes... Lever pressure is good but the stopping power isn't there.
Overall a great day!
Thanks to all those that gave advice and got their hands dirty - Brent Watson, Scott Griffiths, Murray Cross, Bernard Harnett and others.
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]]> Skunk https://www.kiwibiker.co.nz/forums/entry.php/2830-It-runs Just to prove it lives... https://www.kiwibiker.co.nz/forums/entry.php/2825-Just-to-prove-it-lives Sun, 29 Sep 2013 00:52:23 GMT http://youtu.be/Bij9RLnQq9Q http://youtu.be/Bij9RLnQq9Q ]]> Skunk https://www.kiwibiker.co.nz/forums/entry.php/2825-Just-to-prove-it-lives ZXRD400 rebuild https://www.kiwibiker.co.nz/forums/entry.php/2818-ZXRD400-rebuild Sat, 14 Sep 2013 08:07:35 GMT The 400 has been rebuilt and tested and some problems were found. I decided a complete strip and reassembly was the best idea. A thorough check and test of every step lead to the conclusion that the engine itself is fine. No air at all. The carbs however were a different story. I did a LOT of... The 400 has been rebuilt and tested and some problems were found. I decided a complete strip and reassembly was the best idea.
A thorough check and test of every step lead to the conclusion that the engine itself is fine. No air at all.
The carbs however were a different story. I did a LOT of research into the carbs and discovered that there isn't a lot of places to find the information required to check everything.
When I did find the info it pointed to the reasons for it not running well. With the assumptions about what connects where based on both LC carbs, TZR carbs and various other two strokers the carbs had been connected wrong.
With this now sorted the bike runs better but very rich. Hopefully the GPR Team will sort this in the next month. I'm hoping to take it to the Battle of the Buckets in October.

Yes the front number board is huge - it's the size of the top fairing frame. The top fairing and bits have not been made yet.
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]]> Skunk https://www.kiwibiker.co.nz/forums/entry.php/2818-ZXRD400-rebuild Race Debut... or not. https://www.kiwibiker.co.nz/forums/entry.php/2670-Race-Debut-or-not Mon, 14 Jan 2013 03:27:45 GMT The Race debut of the ZXRD400 didn't happen.
Something is not right with the tuning and I'm going to do a bit of testing once the damage is repaired.
Oh yes, the damage…
Practice Day. First session it was very rich so I went from the 220mj to the 210mj. I only did an 'out lap' and an 'in lap' (so one full lap and some).
Second session. 'Out lap' it felt better straight away but I decided to come in to check it over. It had other ideas and it seized on me going into Higgins. I was changing down three going in (gearing is not right and the temporary chambers are dragging everywhere). The first down change was fine, second one didn't feel right and the third one was a lockup.
Remove the heads and the piston tops look fine. Push them down to BDC and I have buildup in four corners of the barrel on the left barrel. Remove the headers and left piston has a score up the front.
Lift the barrel (it won't quite come off in the bike) and the piston is scored badly in four corners and one up the front all on the lower portion of the piston. No damage at the ring area.
So; the engine is coming out and going off to Pete Sales for repair. At least one piston required ($193) and we'll see what other expenses there are. At the moment Round 2 is looking very dubious and the cash box is nearly empty.
But at least I had fun and in talking to a few people (and a lucky comment to Paul King) has lead to many improvements and greater knowledge of what I've doing. ]]> Skunk https://www.kiwibiker.co.nz/forums/entry.php/2670-Race-Debut-or-not Revised the carburation https://www.kiwibiker.co.nz/forums/entry.php/2666-Revised-the-carburation Sun, 06 Jan 2013 06:10:00 GMT I've been given a couple of VM28 carbs from an RD400. All the standard jets etc in place so it was an easy job of cleaning them up and inserting the 'baseline' jets and needles.
I've remade a couple of parts I wasn't 100% happy with and added the tailpiece and hugger. Also added is the top fairing bracket with will hold the number board for now.
A change has been made to the gearing so we'll see the results soon.
Next time out will be PMCC Track day on the 12th of Jan at Manfeild. The bike had better go as I've now entered the series! ]]> Skunk https://www.kiwibiker.co.nz/forums/entry.php/2666-Revised-the-carburation First Run https://www.kiwibiker.co.nz/forums/entry.php/2652-First-Run Fri, 30 Nov 2012 10:51:20 GMT I took the bike to the Vic Club Track Day to have a go at tuning it. Static tuning seemed pretty good. Idled well and reved cleanly etc. Not that it means much in the real world.
Anyway, first session I well out fairly cautious as I didn't know how anything was going to interact.
A big of bogging at lower revs exiting turn 1 that dipping the clutch took care of and away she went though turn 2 and into splash. I now had three things to sort.
1. the fuelling (bogging)
2. the brakes (too soft)
3. the gearing.
It was tall and very close ratio. I went up four gears in turn 2! The bike was pulling quite well. Going down the back straight I decided things weren't as good as they first seemed and coming onto the front straight it started to miss a bit.
Clutch in and hand up I pulled into the infield.

On checking the plugs it looked to be VERY lean. So the 260's came out and some borrowed (drilled) jets went in. The should have been 350 matches. Session 2 saw me get as far as turn 4 (nearly). The bike would not clear it's throat no matter what. VERY rich this time.

Next we (Myself, Jason Lincoln and Andy McDonald) tried some 300 jets and it would respond either. We blocked the power jet with a similar result. rechecked everything and replaced a missing retainer washer under the main jet. With the bike sounding better I took to the track again. The run down pit lane did not bode well... Full throttle and nothing was happening. Clutch in and rev it - good. Onto the track and it dropped a plug.

So; session 1 = 1 lap, session 2 = 0.5 lap, session = .25 lap. Total 1.75 laps. I decided I shouldn't try anymore. Andy suggested the carbs weren't a good match to the bike so I'm on the hunt for the right carbs now.

I now have the hugger and tailpiece for the bike too. It's getting there slowly and it's still on track for the Pacific Clubs Summer Series. ]]> Skunk https://www.kiwibiker.co.nz/forums/entry.php/2652-First-Run Delay https://www.kiwibiker.co.nz/forums/entry.php/2618-Delay Thu, 04 Oct 2012 08:25:13 GMT I finally got an opportunity to get the 400 on the Dyno. As it was days after a two day race meeting I wasn't really ready. The bike was though. So, with a sore throat, aching ears and head, I loaded the bike, toolbox and laptop into the van and headed to the Dyno.

Rich had first go with his Bucket setting up a base run. I watched his HP figures and secretly hoped the 400 would at least get the same figure...

Rolled the ZXRD onto the Dyno and kicked it into life. Well, kicked it over for a while anyway. Rolled it off and tried to find the issue. No broken wires, no disconnects. Plug in the laptop and check the Ignitech. No Connection it said. Check the battery. Flat. It went from 14volts to flat in one week. While switched off.

Oh well. That was a shit.

PS: The week got worse after that. ]]> Skunk https://www.kiwibiker.co.nz/forums/entry.php/2618-Delay Better running https://www.kiwibiker.co.nz/forums/entry.php/2601-Better-running Tue, 04 Sep 2012 10:40:41 GMT Had a bit more time to look at things. F5Dave came round and we started it up and looked and poked a bit and lit it up with a timing light. Dave made suggestions and went home to finish his bike and I got into following the suggestions. With the multiple minor tweaks done I fired it up again. ... Had a bit more time to look at things. F5Dave came round and we started it up and looked and poked a bit and lit it up with a timing light.
Dave made suggestions and went home to finish his bike and I got into following the suggestions.
With the multiple minor tweaks done I fired it up again.

Runs pretty sweet. Revs up OK, too slow on the back-off but that could change with timing/advance curve/jetting changes.

It all looks close. Lack of money says otherwise. still - I'm determined to get it going soon now. ]]> Skunk https://www.kiwibiker.co.nz/forums/entry.php/2601-Better-running Pre-ignition... https://www.kiwibiker.co.nz/forums/entry.php/2581-Pre-ignition Sun, 19 Aug 2012 04:07:42 GMT Bugger. I started the bike up (1 kick!) and started adjusting the curve on the Ignitech. It was liking the advance a lot (about 17° total). then it started running higher in the rev range; about 7000rpm. Shut the throttle. Still revving. Switch off. Still revving. Disconnect all power and... Bugger. I started the bike up (1 kick!) and started adjusting the curve on the Ignitech. It was liking the advance a lot (about 17° total). then it started running higher in the rev range; about 7000rpm.
Shut the throttle. Still revving.
Switch off. Still revving.
Disconnect all power and computer. Still revving.
Pull plug leads off. Still revving.
Put foot over tail pipes. Stops.

Bugger. Shit. Pull heads off. Bugger.
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]]> Skunk https://www.kiwibiker.co.nz/forums/entry.php/2581-Pre-ignition ZXRD400 (The Kawa-maha) https://www.kiwibiker.co.nz/forums/entry.php/2575-ZXRD400-(The-Kawa-maha) Sun, 12 Aug 2012 10:33:07 GMT The bike is fully wired with the ignitech and has been running. As it now has 'go' I decided to give it some 'woah'. Standard ZXR250 brakes up front and rear. Should be enough for now. I remember it being pretty good on the brakes.

I've been looking at the pickup system I'd made up and decided that to needed redoing. First step was to strip the flywheel to pieces and remove the steel and magnets.
Next step was to make a new backplate and mount points for the two pickups. As the mounting plate is held by three screws trying to find a point I could mount two pickups 90° apart where they didn't foul the webs and cover proved to be time consuming. Nevertheless it is done.
Now to build a new flywheel that basically just holds the trigger lobe. I didn't find a piece of ali 100mm dia in my garage so I called Sketchy to see where I could get some. He's got a piece. And it's turned down to 80 dia at one end. Sweet - that means it'll fit my lathe. Several hours later and we have a result:
Old flywheel: 1.57kg.
New flywheel: 0.95 kg.
Was it worth a weekend?

Damn straight.

Pics are:
Front of flywheel and the trigger (not attached)
Rear of Flywheel marked for cutting a recess
Modified Woodruff key
Ignitech computer
Shot of modified backplate
Coils marked so I don't forget (again)
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]]> Skunk https://www.kiwibiker.co.nz/forums/entry.php/2575-ZXRD400-(The-Kawa-maha) Ignitech purchased https://www.kiwibiker.co.nz/forums/entry.php/2480-Ignitech-purchased Mon, 02 Apr 2012 09:57:19 GMT Well, finally a little progress with the purchase of the Ignitech ignition. Sorting the wiring and then instal the curve supplied by Wobbly (included in the price). Maybe I will make it to the 2013 PMCC Summer Series... Well, finally a little progress with the purchase of the Ignitech ignition. Sorting the wiring and then instal the curve supplied by Wobbly (included in the price).
Maybe I will make it to the 2013 PMCC Summer Series... ]]> Skunk https://www.kiwibiker.co.nz/forums/entry.php/2480-Ignitech-purchased Stationary. https://www.kiwibiker.co.nz/forums/entry.php/2036-Stationary Tue, 12 Apr 2011 01:36:31 GMT The project is waiting for funds to continue.

A programmable CDI required and bills to pay. I'm hoping it will be running in about a years time if things go well. ]]> Skunk https://www.kiwibiker.co.nz/forums/entry.php/2036-Stationary Progress update https://www.kiwibiker.co.nz/forums/entry.php/1844-Progress-update Sat, 27 Nov 2010 02:05:34 GMT Expert and others are correct about the polarity of the pickups. I have fixed that issue. The pickups are now at 90° and it works. I'm working on the final design backplate now and mounting the triggers so they adjust as a pair (the software for the CDI allows for any other changes to the timing to be made).
I had intended to race it at the Taupo Road Race Spectacular but a lack of money has forced me to withdraw my entry. That also means not much is happening on the project as funds have run out for the Ignitech CDI and the entry fees to race the thing!
I aim to have it completed by early next year shortly after I win Lotto (or my wife finds a job...) ]]> Skunk https://www.kiwibiker.co.nz/forums/entry.php/1844-Progress-update CDI sorted https://www.kiwibiker.co.nz/forums/entry.php/1783-CDI-sorted Sun, 24 Oct 2010 08:57:16 GMT The CDI issues have been resolved. The Jaycar cheapies work well - when the correct wires are attached.
The stator I was using had the high voltage CDI wires cut off and only the lighting circuit wires left. Novice that I am I used those. Wrong. It works on the RGV CDI as that has it's own step up transformer in the unit so it doesn't need the high voltage charge. In fact the RGV stator only has power that will be rectified. I don't know that.
Anyway, back to the current CDI set up. The stator has three wires; brown, red and black. I've run the black to earth (both chassis, engine and CDI), the brown and red to each CDI for power.

EDIT: the miss has been sorted. You would expect the pickups to fire the coils at the same point as the trigger comes pass wouldn't you? Well, my setup doesn't.
For whatever reason coil one fires as the trigger exits the pickup and coil two fires as the trigger enters the pickup. This means the included angle for the 90° firing is: 135°! Yep, I was wrong to assume I could set #1 at 2mm BTDC and then set #2 90° later. Strangely the RGV has the triggers set at 90° so there must be something else going on in the CDI or loom that I can't see.

Never mind - it's only taken 3 weeks to get the new setup running. I have a very patient wife.

I now need to make a new back plate, flywheel and mounts for the triggers. Anyone got spares?
I also need a replacement RD400 flywheel cover... Yeah, right. ]]> Skunk https://www.kiwibiker.co.nz/forums/entry.php/1783-CDI-sorted