Post race-bingle NC30 rebuild - pic thread

[StrayAlien]

Picking up new carbs tomorrow - I had to sell my grandmother again,.. again .. again ...

They are NC30 carbs and off a 'working bike' this time, so let's see how we go. They cost twice what the last ones did and I thought the last ones were steep.

RoninZX-10R: I am pretty happy with the EBCs I have, no issues. I was dissapointed that the floaters didn't arrived (because that is what I thought I ordered), but no issues. They feel pretty good. I can get the back wheel off the ground when braking so they must be okay.

In the bingle I smashed my brake master so I had to get a new one of those .. so it'll be interesting to see how a new master cylinder feels. Actually, I didn't fully smash it ... just bits broken off it .. so I also bought a master cylinder rebuild kit just in case the new level/master I bought was crap .... I am sure there will be some adventure (and pics) on that later.

With new carbs tomorrow will be "get the bike started day", and a mate is coming over so joining forces we might be able get that HRC linkage on too.

[Drunkn Munky]

Good stuff hope it starts without to much trouble. One thing your notice with the hrc link fitted is you now have masses of clearence for the exhaust which if you have a full system is a god send, I cant understand why honda didnt use this link from the start.

[StrayAlien]

Thanks. That is great! I have stuff-all clearance at the moment with my Ethos system. :-)

[StrayAlien]

Okay.

Time for the heads. Although I didn't get a pic, when I crashed grass and mud was sucked through the carbs and when I took the carbs off I could see it in the inlet tracts.

Nice.

So, I decided to get the heads off to check and while I was there do a refurb. This involved getting carbon off stuff, re-seating the valves, replacing the valve guide seals and doing a general health check to see if things were within wear limits.

These engines are a marvel. Really. This bike has never been road registered in Australia - it does not even have a compliance plate. I am guessing it was imported into Australia in the mid 1990's purely for racing and that is what it has done all its life.

Yet ... it uses no oil, feels tight, and absolutely everything I could check was within tolerance. I did not check inner diameters of valve guides, not did I plastiguage anything - just what I could do with my micrometer.

So, not far off 20 years of racing and it is still fantastic. Like i said, a marvel. Well done Mr Honda.

Anyways ...

Engine on the bench. Getting the covers off is easy.



What a delight. I am a sucker for beautiful engine parts, and it is all very sweet up here. Simple too. Compare this to the head of a Ducati.



Note the lettering also. Follow what the haynes book says, take some pics along the way and, even thought I have never done this before, it was like A-B-C. Things are numbered and lettered and let you know what is intake or exhaust. Just take it slow and double or triple check everything you do with the Haynes manual and the NC30 workshop manual. It was, surprisingly easy.

Get the cams and stuff off:







When getting things off, have loads of zip lock lunch bags handy with a marker pen:



I used 6 labelled bags per cylinder, say for cylinder 3:

3 IN (for intake rocker arm pin and stuff)
3 EX (.. and for exhaust)
3 IN i (intake inner valve - closest to middle of engine)
3 IN o (intake outer value - closest to outer of engine)
3 EX i (exhaust inner valve)
3 EX o (exhaust outer valve)

I kept cylinder bags together and in order. It may seem excessive, but before putting anything into a bag or getting it out to I said out loud what I was doing (like '3 EX i') and checked and checked again the actual cylinder / valve I was working on. To be sure .. to be sure.

I didn't want anything to fall into the 'open invitation' that is an open engine, so I was cautious to plug stuff up:



Both heads ready to come off now:



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[StrayAlien]

The heads came off without too much fuss and, yes, there was crap in them (not shown). One had resting water in it and had started a thin layer of rust on the cylinder wall.



All looks nice on this one - nothing scary. However, the water was actually still inside the cylinders - that is what the drops are, not cooling system water. Isn't that amazing - 'water tight' after 20 years. :-)



Time to set about doing the valves.

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[StrayAlien]

It took me a while to get around to doing the valves. Honestly, I was a bit intimidated by this lapping and reseating thing. Anyways, a few gins and some late nights in the garage were required.

I used a water based paste ('Pep') rather than an oil based one to make things easier to clean. In theory. I think they are all too dry in the packet to you need to add some water to make it a bit easier to spread around:



yet again, late night in the garage:



Note the little tub of oil. These valves are so damn small that you need the smallest sucky-cuppy valve stick thingy you can get. And because they are so small it is difficult to get them to hold suction. So .. the oil was to help hold suction on a valve while it was rotated. So much for water-based ...



Also note the writing on each : 1IN/EX and 1 IN i/o etc. Here is another view:



The writing comes off easy, but it was easy to know and check what valve I was getting out of a bag and where it went. Note some carbon gone. The dremel abrasive pads where used to clean carbon from heads and valve. It worked well.

So, getting there, still some work, but better than before:



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[StrayAlien]

My $25 valve spring compressor from ebay helped me get the valves and collets in, and during disassembly .. out.







.... and a surprisingly short amount of time later:



... we're getting there. I was finally starting to empty bags rather than fill them. Man, it does feel GOOD!!





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[StrayAlien]

The dremel pads were also used to clean up the surfaces before getting things back together:





And I used acetone to make sure they were free of grime before reassembly.

New gaskets on:



Yes, I was a bit enthusiastic on the oil in the cylinders, but I did get some out afterwards.

With heads back on, which was pretty easy, time for the cams.



Note the liberal usage of 'moly-oil', just engine oil with moly-grease stirred in.



With heads back on it was now time to recheck the valve clearances. This was much easier than I expected and pretty straight forward - again, try it compared to a Ducati!

I found it easier to have all feeler gauges lined up for use rather than having them in their holder:



The $30 micrometer was priceless during all of this. It might not be good enough for building a space-shuttle, but for checking tolerances, pretty good. I checked it against a new Honda shim and it was almost the same as what the shim said, so good enough for now.



I needed a few shims, and I got some from Honda but they said the others I needed had to come from Japan, so I went to Precision Shims in Melbourne for a few of theirs - about the same price but made in smaller increments so you can be more, erm, precise, and the bloke makes them, so he is never out of stock!

I did try to grind a shim down a bit but, man, that is a myth, these things are pretty difficult to grind down by hand! Just get a new one the right size.

So, done ... all buttoned up now with engine rotating nicely. FINALLY ready to begin bike reassembly!!!!

[StrayAlien]

Empty(ish) Bench!



Where could that engine be? Over on blocks of wood near the bike while I figure out just how to get the damn thing back in! That's where.



Okay, nudged underneath. Note how far the rear engine mount is away from 'home'.



Okay, in and very loosely tightened. I actually found it easier to lift the frame and swingarm onto the engine and do it like that. I lowered it over and propped it up and them nudged it here and there until I could get some mounts in. Cold beer after that - it killed my back!



The crash bent the front left 'crash knob' and its bolt. I got a new one from Keables in Melbourne City. Unlike 'pro bolt' that charges a bomb, these guys are trade sellers. Over the counter min sale is about $30 but they have loads of stuff. I got a stack of stuff including a 1000 piece metric washer set and walked away spending less than $60. Amazing.



Hmmm .. also on the left front engine mount there is no spacer. Luckily I now have lots of lovely washers to space things with as Honda to not make the part any more. :-)



To be able to get the engine started again, I'd need a throttle on a handle, so I took a moment to do some clips ons.

These are NSR250 clip ons and I have sanded the laquer off them and given a bit of a polish:



The NSR250 clip ons have a little 'hump' that tucks in under the top triple clamp plate - but I have a tyga one - so the humps must go.



Polishing is okay, but I have left the 'grip' part of the clipon rough:

[StrayAlien]

Okay .. engine in (kind of), no carbs, time to try out the VFR750 axle.

Time for a small late night rant. Disclaimer: yes, there are people that go *really* fast on NC30s on 4.5" rims. Fair enough, I am not a gun and I am not one of them ... yet ( :-) ) but ... screw it .. sue me for having fun.

I have read that HRC supplied a 5" and 5.25" rims for their racers. Cool. I also read that the 250 GP bikes ran between 5" and 5.5" rims. As far as I know, all were 160-ish tyres (I could be wrong), but ... my choice is limited to 160 tyres and rules here says that replacement wheel must be from the same manufacturer as the bike and must NOT be lighter than stock. There you go.

So, I am going to give the VFR750 wheel a go. People say the 160 is 'pinched' on 4.5" rim, and it looks it. People say 5.25" is the perfect size for a 160. Too bad. I am not paying for dymags because I cant use them here and to be honest, I cant afford them!

But .. the 750 wheel is actually a LOT heavier than the stock wheel. However, I am figuring that the HRC linkage with some decent suspension along with the extra contact patch of the 5" rim will be pretty cool. I hope it will be despite the extra unsprung weight. I do know what light wheels can do for a bike, I have BSTs on my 999 and they are magic (and they don't get much lighter than that).

I understand Rick Oliver does an axle conversion but this is not one of those. My axle, as I understand it, a VFR750 axle, not a modified 400 axle. Why don't I know? I didn't make it, I acquired it - original modifier unknown.

So, here is the two. On the left is the (alleged) 750 axle, on the right is the 400 axle.



They are very similar on the axle side. In fact they are almost precisely the same. My 750 axle has a spacer made for it to nudge the wheel right a bit to keep it centered. I have moved the spacer out a bit to make it more visible.



Another view. Left is 750, right is 400:



First non-straight-forward hurdle is that the inner diameter of the axle if not the same! So .. a different pin is required for your single-sided wheel stand. I paid a few bottles of wines to a friend with a lathe to whip me up this:



... now, with the 750 axle I can at least use the wheel stand. Groovy.

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