Mananon wrote: Is this even worth doing if I leave the backlash gears in? If careful shimming keeps the noise down a bit I’d be keen to give it a go.

I remember some of the RC gurus stating on here that if done properly there shouldn't be any clattery noises, but I'm not too sure of specific details. I just live with the noise, music to my ears.

You will need to raise each cam carrier the same amount that came off the head. Upping the compression is probably more worthwhile than removing the quietening gears, but quite a bit more involved (just removing the quietening gears is a straight forward job).

Oh well, I'll whip of a heads this weekend or sooner if I get chance.
I'll start with lapping the valves and polishing the ports.
In the mean time cammo I can't find my HRC manual with the settings in. Think they must have been on my old, dead laptop. Any chance to could mail them to me or post them here?
Any further advice on skimming the head is greatly appreciated if anyone knows anything. For starters, how much to take off?
Come on you aforementioned gurus, impart some wisdom please.
Once the heads are off I'll get some photos up.
By the way cammo, haynes manual on the way from you're side of the ditch.
Any decent mail order suppliers of stock honda items, like head gaskets, seals and such that you'd recommend?
Thanks again,
Duncan

Just a quick update...
Front rocker cover off, cams out, head bolts loosened, can't get head off. Bum.
Just spent an hour with a soft hammer tapping away to try to gently get it off and after all that time I've got a half mil gap. It rattles but nothing more so far. I think it's binding on the dowels.
Anyway, on a positive note everything under the cover looks like new. No sign of wear at all so I'm pleased with that.
Gaps were all within tolerances.
I'll post photos when I finally get the head off.

Yeah it might be a bit difficult if it's been on there for 20 years.

I've screwed many a mechanical part when I have no patience! Take it slow...

Mananon wrote: Any decent mail order suppliers of stock honda items, like head gaskets, seals and such that you'd recommend?

I often use RB's in Sydney, good bunch and efficient service, just give them a call with your requirements:

http://www.rbimports.com.au/


I would also recommend Rick Oliver off this forum (UK based). He can get virtually any part for you.

It's off. One final tap and it popped right off.
I think it was just the gasket goo. I was going very very gently with it. I have the same habit of getting pissed off and doing something drastic, like a cowbar, so I try to go and do something else when patience is wearing thin.
Inside it's pretty good. Some carbon of course but the crowns aren't fully covered. A quick rub with a cloth has taken most off.
Small lapping stick should arrive tomorrow. Got paste. Polishing heads for doing the ports prob won't be here till next week.
Thanks for the pointer to RB's Cam.

Mananon wrote: Polishing heads heads for doing the ports prob won't be here till next week.

Nice one. Just don't get too carried away with the porting. Unfortunately the copy I have of the nc30 hrc TT-F3 manual is too big to email.

Here's a couple of pages uploaded to photshitbucket that might help. It gives general dimensions of the ports when opened up to hrc specs.

http://i19.photobucket.com/albums/b171/ ... 8ad882.jpg

http://i19.photobucket.com/albums/b171/ ... d52098.jpg


Here's the same sort of info from an rc30 kit manual, only put here so you can make some conclusions from the Jap language manual above (grade of paper etc) - don't port to these measurements!

http://i19.photobucket.com/albums/b171/ ... 0e9cae.jpg

http://i19.photobucket.com/albums/b171/ ... 2b2c3d.jpg


A lot of things in the rc30 kit manual also apply in some ways to the nc30.

Second link didn't work Cam but looking at the RC bits (a bit missing off the left side and I can barely read the text) I think it's saying to just polish and remove casting burs. It also seems to say something like you can skim 0.2mm off the head. Can you have a look and confirm if I'm reading that right Cam?
I did find this earlier:
http://translate.google.co.nz/translate ... n%26sa%3DG
A few pics in there.
And I wish I could realy make sense of all of this:
http://translate.google.co.nz/translate ... n%26sa%3DG

Anyway, I was going to get some photos of the heads, ports, valves etc but the camera is flat.
I'll get some up shortly.
Cheers,

Just a thought...
Won't I need shims under the cam gear case mounts?
The case set bolt holds it in the right place further down towards the crank but taking material off the head will leave the four bolt points, where the case mounts on to the head, with a gap at the back.

Photos at last.
This is the front heads with the front (exhaust) cam loosely in position.
For those who haven't seen this before, the black marks here and there are marker pen done at assembly. The thinner gear on the right of the two gears is the backlash gear with the circlip holding this on just to the right again. Top right I've taken out one of the cam shims (just lift them out with you're fingernails) and put it on the edge of the spark plug housing so you can see what they look like. These are what you change if you're clearances are out.


This one is of course the underside of the head showing the valves. Exhaust valves at the bottom. The black stuff on the face is gasket goo and will need to be cleaned off before reassembly. I'll be lapping the valves tomorrow if the lapping stick comes.


This one is the piston crowns, cylinders, water jacket (still a bit of coolant to be seen) and into the bowels of the beast. I've given the right crown a wipe with a paraffin soaked rag to take off the carbon deposits. On the left cylinder you can see gunk (technical term) deposited around the top where the rings don't rub it away and this needs to be cleaned too.


I'll post more photos as I progress.
Duncan

Good progress!

Looks to be in better condition than the engine I have apart:




Blown engine. I managed to disintegrate a piston and put a conrod through the side of the case...

All operator error unfortunately!