Road NC30 to track NC30 in 100 million years and counting

[Martin]

Cutting to the chase I bought this



in December 2006 which meant that I decided to turn this



into a track bike. It took a day to completely strip the bike down to a bare frame, engine, forks, swing arm etc. so that everything could be thoroughly cleaned, re-greased, seals changed and so on and so forth. Unfortunately this is as about as far as I got. For roughly 18 months the ‘bike’ was in pieces in various different places of my parents house until about 8 months ago. After a chat with Rhory following an RC Dyno day at GT motorcycles, I started to put the thing back together. Basically Rhory I’m blaming you!!!

First things first it was a case of getting the rolling chassis back together. I cleaned the rear hub out, passed the rear brake line through the swing arm, replaced all the bearings and fitted new discs and as said earlier re-greased everything that needed re-greasing resulting in this.



It was at this point that I was sent an HRC VFR400 F3 TT manual by a person who shall remain nameless and that’s when all the real fun began! First thing to do was to get busy with a hacksaw on the undertray and subframe as per the instructions in the manual and you end up with something like this.





From here I thought it best to strip the loom as obviously I wasn’t going to be needing lights. Also because the ignition barrel holder was going to be lopped off, sorry expertly removed in a professional and safe manner, there was no need for the ignition switch. However I wanted the added security of a hidden relocated ignition switch rather than just relying on the kill switch so I’ve left the wiring for it albeit considerably paired down. Other things to be removed from the loom were the wiring for the fan, fan switch, all indicators and brake lights including the wiring for the brake light switches. Because so much was removed I could also get rid of the fuse box and use just one 10amp inline fuse for the ignition. This is what I ended up with and it appears to work well.

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More chopping time as now there was no speedo, there was no need for the speedo cable or the cover over the sprocket that the speedo drive bolts to so off it came again once again as per the HRC manual.



At this point it was finally time for the engine to go back in following the replacement of all the major gaskets. Once the engine was in I could then get on with mounting the exhaust and radiators. I was slightly worried about the engine as it had sat for over 2 years without any oil in it, hopefully Honda build quality would live up to it’s name and my neglect of the bike wouldn’t come back to kick me in the jangley bits. With new exhaust gaskets and almost everything back in place it was starting to resemble a motorcycle again. A crankcase breather was the next thing on my extensive to do list. Ideally I’d love an HRC breather/catch tank but I think the chances of ever finding one are pretty much none so this’ll have to do, a crusty bit of blue pipe venting into the cast part of the frame.



Time to HRC F3 the carbs. There were a couple of limiting factors with doing this properly, the first being the budget and the second being the unavailability of parts. Rick Oliver does replica needle, emulsion tubes and jet kits but seeing as I already had a set of adjustable needles to work with I thought it made sense to at least try to use what I had. If it worked, then great, if it didn’t I’d get a RO rep kit and work from there. Other than the emulsion tubes, needles, pilot jets and main jets the other major differences between the standard NC carb set up and the HRC one is as follows.

- No Airbox so to speak of, the plenum chamber is made up of the underside of the tank with the insulation removed and the HRC air tray.
- Rounded bottom carb slides, they have their own NL1 HRC part number but seem to be in certain NC21/24 carbs if your prepared to look hard enough, I’m not for the difference that they’ll make.
- Shorter velocity stacks.
- Drilled carb tray and no air filter.

To see what a proper set of HRC carbs look like have a look at this link to Mike Lohmeyer’s web site.

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This is a picture of my dodgy garden shed bodge job HRC copy carbs, can you see the difference?!



The HRC stacks have a little cover to reduce the airflow passing through the brass tube underneath. When you cut down the original stacks to replicate the HRC ones you don’t have this cover so you have to reduce the airflow another way to get the carbs to work properly. Consequently the best way it seems is to take an M6 button head bolt, drill a 3mm hole down the length of it(the bolt only needs to be 10mm long), thread the brass tube in the carbs and insert the bolt. Hey presto you have an air restrictor and a set of velocity stacks that seem to work in a similar way as the HRC “rubber boots”.



I already had an HRC copy CF airtray so that was something I didn’t need to buy. I also thought, seeing as running HRC open carbs involves running without an air filter it would be prudent to at least install something that would prevent major pieces of crap being scooped up through the main air intake and into the carbs. The result is this, the gauze from the back of an OE air filter bent at 90 degrees with a piece of HRC filter foam cable tied to it and inserted into the V between the headstock and frame cross member. Hopefully it’ll keep the worst out.




The next step was to get the jetting done. As you now have lots more air reaching the carbs it’s necessary to use not only larger main jets but also larger pilot jets and I have to thank Rhory for pointing me in the right direction with this despite the fact that I have the HRC manual. There is still a little bit of guesswork (ok, a lot of guesswork!) involved here and to be honest until I get the bike on Stephens Dyno I can only get the jetting roughly in the right area. So with an order to Rick Oliver for main jets, pilot jets and ER10’s this is what I’ve ended up with.

Main jets:- Keihin 150 front 152 rear
Pilot jets:- 40’s all round
Air screws:- 2 turns out
Needles:- FI adjustable fronts 2nd clip from bottom
Rears 2nd clip from bottom with 0.5mm washer underneath
Carb slide holes drilled to 2.5mm
Float heights set to standard

Now was the time for the loom to go back in and see if my butchery worked…



Huzzah!!! At least the dash lights come on. Bare in mind, as I said earlier, that the bike at this point hasn’t run for 2 ½ years and not even had any oil in it for the same amount of time, I was dreading trying to start the poor thing. New oil, coolant, a drop of oil down the bores and the engine turned over by hand to make sure nothing had seized (it hadn’t thankfully) and I was ready to put the new plugs in and see what happened. After a couple of hesitant chug chugs and a few turns of the idle adjuster because I’d forgotten to do this after balancing the carbs, a wonderful V4 burble started to echo around the courtyard along with lots of Woohoo’s and declarations of how clever a certain so and so was. I even got a congratulatory mug of tea from Rach. The NC lives once more, happy days. I let the bike warm up and blipped the throttle and much to my surprise there didn’t seem to be any hesitation or big puffs of smoke pouring out of anywhere. The fuelling seems to be at a fairly good base setting but until the bike is under load I can’t really tell.

The next step was to get rid of the Brembo callipers and radial master cylinder as it simply isn’t necessary and is complete overkill. I put the radial M/C on the B1h which works a treat and the Nissin M/C from the B1h (14mm bore size) onto the NC which once teamed up with standard NC calipers is a fantastic combination.



In order to save my feet, fingers and other sticky out bits I made up a shark fin thingy out of some aluminium plate that I had lying about. I’m quite pleased with how it turned out actually, sure it’s not as good as a bought one but it cost about 70 pence to make, it’ll do.



That’s pretty much how far I’ve got for the moment. The next thing on the list is to get a big bottom radiator and some body work. The current spec of the bike is as follows.

-RVF 17” rear wheel
-WP shock. Adjustable for preload, compression, rebound, and height
-RO (Rick Oliver) adapted linkage
-WP fork springs
-NHK damper with Harris fork mount
-RO Quick action throttle kit
-Titanium rear wheel nut, sprocket studs, lower yoke bolts, front axle bolt, disc bolts and various other ones dotted about.
-Braided lines front and back with rear line running through the swing arm
-Chopped subframe as per HRC manual
-Chopped undertray as per HRC manual
-Homemade race loom
-NGK ER10 plugs
-Chopped sprocket cover as per HRC manual
-Renthal 15/41 sprockets
-Homemade shark fin
-Yamamoto Spec-A half system, restrictor removed
-Standard callipers with Honda race pads and Nissin 14mm master cylinder
-SES meter stay
-Aluminium screen brace
-Carbon fibre HRC copy air tray
-Lowered top rad for HRC air tray clearance
-RLR top and bottom alloy kit rads
-Cooling fan removed
-Chopped top yoke as per HRC manual
-Adapted standard Tacho/temp dash to take neutral/oil pressure lights
-HRC carbs
Main jets:- Keihin 147.5 front 150 rear
Pilot jets:- 40’s all round
Air screws:- 1 1/2 turns out
HRC slides
HRC stacks
Float heights set to standard
Needles:- FI adjustable fronts 2nd clip from bottom with 3x 0.5mm washer underneath
rears 2nd clip from bottom with 2x 0.5mm washer underneath
-HRC fuel and coolant catch bottles
-Coerce rearsets
-Alloy bars
-Alloy filler cap
-Loads of cable ties
-Some blood, a fair bit of sweat but thankfully no tears yet…..

I think that’s pretty much everything for the moment, however I’m sure that’ll change. Here’s how the bike looks at the moment.

[CRM]

So its safe to say it saw europe once and then it was cards for the road again ?
looking good mate

[Martin]

It went to Germany aswell mate, do you not remember being enveloped in a huge plume of smoke down the straight at the Ring :D I think I'll probably end up getting a cheeky daytime MOT for it eventually though.

[CRM]

Lol, oh yeah i do remember that, it was infront of me most of the time and i recall choking on the fumes, then on the straight i thought it was going to blow

[CMSMJ1]

That kicks ass man...love it.

Good old Gertie!!

[Smev]

That looks awesome Martin! :D

Great write up on it too - keep the updates coming.

Maes me want to play around with the carbs more on my bike - but I just need to get out and ride it!!

Smev

[TonyB]

Nice one Martin!
Hopefully the dyno printout will look as good.

T

[Martin]

Nice one Martin!
Hopefully the dyno printout will look as good.

T

Hey Tony. LOL, don't count on it mate!

[mo haggs]

looking great.
one question though - is it for track days only or will you race it?

reason i ask is - if a scrutineer see's the front sprocket with no cover they wont pass the bike and you won't get out.

[royster81]

just had a proper read of this fella and i'm over the moon for you,so glad to see old gerty up and running and in one piece again, but i'm not overly happy at the fact ,once again, i'm being blamed for things i'm not really to blame for hahahaha

reading through the list and visually our bikes are almost the same, and it's funny as the only things i remember chatting to you about where the carbs and the F3 manual.

if you can keep the work going and i look forward to seeing what you have to say about it getting a run on the dyno with stephen at the wheel,all you need now is a period paint scheme and some GREEN number boards.