NC30 track bike not been used in 8-10yrs, where to start?

[28hodge]

Cleaned up the rest of carb 2 last night then took one of the rear carbs apart last night carb 3 i think, 120 main which is UK standard.

One question why are the UK bikes rear cylinders jetted leaner than the fronts, id have thought that the resr cylinders would run hotter and need more fuel to compensate and keep them cool??

I might be wrong saying this but i thought all the other import models run with leaner ie smaller jets in the front cylinders and then larger ones in the rear?

Anyway got a pic of the needle.



is that a standard needle? it has no engravings on it so no idea what it is to be honest, can someone educate me please.

Also any ideas what this M engraved in the carb means or demotes?



and heres a closer clearer pic



any ideas anyone?

[28hodge]

Hi,

just been out finishing up cleaning the carbs, when i looked at what i think are the vacumm tubes, the t piece that runs between the two carbs, one for the front one for the rear set, where they seal on the union of the carb body is a rubber ring, all mine, bar one have perished and snapped, these need to be replaced id guess to provide a air tight seal???

i cant see how they can be replaced without spliting the carbs, am i right on this?? also what are the rings called so i can get them ordered up? sorry to come with nothing but questions all the time.

Thanks

[Cammo]

The T pieces lead to the sub air filter, the air displaced by the carbs slides is filtered. The rubber rings are often perished. I haven't always bothered with replacing them in the past, what that means is you'll get unfiltered air into the slide area, perhaps accelerating wear.

Yes, you'll need to split the carbs if you want to put new ones on.

[28hodge]

Nice one Cammo, thanks very much

[Neosophist]

Cleaned up the rest of carb 2 last night then took one of the rear carbs apart last night carb 3 i think, 120 main which is UK standard.

One question why are the UK bikes rear cylinders jetted leaner than the fronts, id have thought that the resr cylinders would run hotter and need more fuel to compensate and keep them cool??

I might be wrong saying this but i thought all the other import models run with leaner ie smaller jets in the front cylinders and then larger ones in the rear?

Anyway got a pic of the needle.



is that a standard needle? it has no engravings on it so no idea what it is to be honest, can someone educate me please.

Also any ideas what this M engraved in the carb means or demotes?



and heres a closer clearer pic



any ideas anyone?

Hmm.. thats really interesting.. stock needles are NOT adjustable.. you have adjustable needles there my friend.

Seeing as it's a track bike i'm not surprised, looks like it's been set-up properly.. the M was probably by whoever set the carbs up, to either indicate the state of tune etc.

Did you record all the carb-settings before changing them? If the bike was setup by a dyno (as it looks) the settings were probably very close to perfect and might not be at factory.

The UK getting is 120f/122r I think...!? Do you have the carbs the right way around!?

The reason for this is the rear cylinders do run slightly hotter... not becuase they are at the rear either (this isn't an aircooled bike!)

The reason is that the coolant flow around the engine reaches the rear cylinders last, which is why they run slightly hotter...

[28hodge]

Yeah that was my thinking, the bike was used for racing, and so im guessing it was setup to run properly and as such i havent changed anything when i have taken the carbs apart, just cleaned them up with petrol and a tooth brush, all the pilots were blocked so cleaned them up etc.

Checked the mains again and its defo go 122.5 in the front and 120 in the rear, ive left it as is, i'll get it dynoed when i finish all the other jobs and get it running and see what it makes. im hoping for a healthy stock motor.

I assumed the carbs were marked by the tuner/dyno tech who did them, just wondering if anyone new who the M was? the bike was last raced late 90's with emra, as its got the scroot stickers on it.

Next week im going to bring the forks to work with me and service them.

[28hodge]

got some work done these last couple of weeks, tho working away from home is not helping progress!!

Checked all valve clearances and all within tolerance, so left everything else alone and put the rocker covers back on and refitted the cleaned carbs, see how it runs before i take anything else to bits!! one thing tho, the rear rocker cover was clean and shiny inside, where as the rocker to the front cyclinders was brown and grimy??? is this normal, seemed odd how they were so different?

Anyway soaked the carb rubbers in fuel over night and then went home to pray they would fit the next morning.
which thankfully they did pretty easily with a bit of prizing and the help of a lump hammer.

Next brakes and hit a bit of a sticking point, the brakes on the bike are not standard VFR brakes, i think they are early cbr600 brakes or honda Hornet brakes. can anybody confirm??





pic of the pads.


Stripped them but can i buggery get the pistons out, think id best get a seal kit for the MC and then pump the pistons out.

Also one of the pins has had the allen key end on it stuffed, tried to get it out with vice grips on the pin shaft but it just twisted and sheared so i think that caliper is shafted, so ebay for a new one when i figure out what it is, if anybody knows then gimme a shout, better still if anybody knows and has one lying around let me know, its a L/H one.

This weekend forks in bits and service i think.

Thanks

[CMSMJ1]

Bad news on the brakes - you'll have got NC23/29 fork sliders fitted to the bike and so you canont just get some proper brake calipers fitted.

If you are sorting the forks, try to get some NC30 sliders and then some NC30 calipers. Sliding calipers are adequate for a road bike when they are freshly serviced and can be OK for racing but my personal preference would be some proper opposed piston brakes rather than these stinkers.

[28hodge]

the calipers use a bracket to fit to the forks? does this make any difference?




Heres a couple of pics of the fork slider, ive brought them to work with me to strip this week, but like a nugget forgot to loosen the fork top bolt before i came down so not been able to do anythin with them.

[CMSMJ1]

They are not NC30 sliders and it seems strange to have sliding calipers bolted on with brackets! Waste of unsprung weight and for sub optimal calipers.