Workin on the head in my front room , in the warm, good light, Lino on the floor and it was going quite well until I dropped a collet. Thought it would be easy to find but no. Carried on and replacement valves lapped in ,remaining valves cleaned up and measured, oiled before refitting, springs back in the right way round and re-shimmed based on the previous clearances before the head came off ( will check them again once the cams are back on.) Just waitin on another collet and hopefully refit the head and cam gear.

I've heard that tightening the cam down is tricky, summit about doing No.3 first and then sequentially . Any pointers gratefully received.

Trying to avoid the balls ache of refitting the carbs by buying new rubbers and non rounded out screws on the clamps.. Cant see any reason for it to not go to plan .
Sfunny how once you get into it and the need to take everything else off to get to it that the list of tasks to get it back on the road gets longer.

Sounds like you're doing great work! We're all rooting for you!!

dirty30-2008 wrote:Workin on the head in my front room , in the warm, good light, Lino on the floor and it was going quite well until I dropped a collet. Thought it would be easy to find but no. Carried on and replacement valves lapped in ,remaining valves cleaned up and measured, oiled before refitting, springs back in the right way round and re-shimmed based on the previous clearances before the head came off ( will check them again once the cams are back on.) Just waitin on another collet and hopefully refit the head and cam gear.

I've heard that tightening the cam down is tricky, summit about doing No.3 first and then sequentially . Any pointers gratefully received.

Trying to avoid the balls ache of refitting the carbs by buying new rubbers and non rounded out screws on the clamps.. Cant see any reason for it to not go to plan .
Sfunny how once you get into it and the need to take everything else off to get to it that the list of tasks to get it back on the road gets longer.

read the service manual in the docuemtns section a couple of times before you put the camshafts back in.. never had any trouble doing it according to the book.. its when you come to bolt them down with the timing off you risk snapping a camshaft.

the nc30 has no fixed cam-gear that needs alinign like on a cbr250 so can gears can just be dropped in and then camshafts lined up.

racingt wrote:Sounds like you're doing great work! We're all rooting for you!!

Yup, this ^

Spoke too soon. Head back on , fitting the cam gear and forgot to tighten the cam gear set bolt (6mm) between the barrels before tightening down. As I tightened it all down two of the cam gear bolts seemed to take a little longer to torque up so I was a little concerned. Took the head back off and I had bent the cam gear bracket.....
So as I dwelled on this I thought I would check out the carbs.....as Neo suggested, and drill the slide and put in the 1mm washer whilst there. Spent an eternity trying to put the diaphragms back in. Seems mine have really swollen over time. Found the best way was to trap the diaphragm by tightening the carb top down and work the diaphragm in gradually tightening it down as you go. Any how I managed to blunt one of the needles J51A... so something else on the shopping list. Good spot was the stuck choke on pot No.4 so this was addressed. Thankfully all jets and nozzles were clear. New RO gaskets all round.

I also took off the carb plate .What a headache that was to put back on. Not only do you have to align the trumpet holes but then ensure all the dowels are seated . Anyone got a method for this please pass it on..
Cam gear arrived this morning but the missus didn't hear the door apparently so picking that up is my priority tomorrow ..

I also took off the carb plate .What a headache that was to put back on. Not only do you have to align the trumpet holes but then ensure all the dowels are seated . Anyone got a method for this please pass it on..

This is my least favourite job on the NC and I still haven't got a good technique. Takes me ages to make sure I'm not trapping or distorting the rubbers and even then - at least 2-3 goes before I get it.

werid.. last weekend i built a set of v45 magna carbs (same as nc30 but bigger), some cbr250 carbs too and didnt have a problem with any of them.

the way I always do it is upside down.

First work out the correct potition of the velocity stacks, they have cutouts for the airjets.

once you can see how they fit located them in the upside down top tray, since they will protrude out the bottom i ususally hold the airtray up off the ground with a stand i have that has clamps on it.

once velocity stakcs are in and lined up ok i just put the carbs down ontop and providing everythings ok sometimes a little wiggling of the stakcs and it goes together, carfuelly turn right way up and bolt in the screws.

bad lukc on the needle, but least you caught the choke slider!

be good in no time.

did you straighten out the bracket/

Thankfully RO had a spare cassette and needle so installed those this afternoon. Finding the cams a bit trickier. I might be being hyper picky but on installing the cams with the T1 mark lined up the rear cam lined up ok but it appears that the front cam although pointing away from the head is marginally off. I can seem to get the cam gear teeth to seat but the index mark is either to the left or right of the camshaft index mark. if I move it one tooth on or back it moves the timing mark away from the crank index mark.
Having got this far I dont want to jeopardize anything so I stopped at this point, plus it was pi##ing down and I was losing the will to carry on. Any pointers gratefully received.

Here is the cam gear. Didn't bother trying to straighten it out.


RO cassette had a bath in paraffin and lightly oiled. Had to reset the face of the setting bolt as it was skewwed slighly but went in fine . Gear meshed and rotated nicely. So on with the camshafts. These are being difficult as the index line is out on the inlet valves by a gnats . Stopped due to bad light and the weather was awful. No centrally heated garage here, working under a large golfing umbrerlla in the pi##ing rain aint funny.

did you tighten the cam-caps down?

ive always found that one of the cam-shafts looks sligltly off until tightened down, i think its due to the backlash gear pushing it slightly out of line until you torque everything down.

Once its all torqued youll soon see if its lined up or not. (dont forget to rotate the engine at least once fully to make sure lines still line up after)