nc30 popping noise

[Dynamohum]

waiting on rubbers coming hopefully have a look in carbs over weekend will use your guide cammo and report findings probably a good excuse to clean them anyway, cannot go wrong the sum total of the bike with the penske and reworked forks was a bargain . had started a frame up build with parts i had lying around then realised i was missing a lot of parts i thought i had then picked this up.

[Dynamohum]

just managed to get some time before work to get the bowls off its running 120s front and 118 rears 8 hole emulsion tubes front and rear ? also noticed that the tray that the trumpets protude through was loose all the screws tightened a good bit the plastic slides are well scuffed with it being unfiltered i guess.

[CMSMJ1]

gonna be very lean like that mate - stick a filter in

[Dynamohum]

just re read cammos guide and the 8 holes are the pilots too much of a rush will check emulsion tubes and needles at weekend after i get some carb cleaner . want to get it running first before shelling out on parts from rick filter carb parts jets needles etc then take it from there.

[CMSMJ1]

Pilots are jsut like mini main jets? Emulsion tubes are a brass tube with holes in both sides.

To be honest man you'll need a filter in it to get it running at all - it will be too lean without one. My race bike uses 120s and a full exhaust and uses std airbox and filter.

No filter will be nasty

[Dynamohum]

Pilots are jsut like mini main jets? Emulsion tubes are a brass tube with holes in both sides.

To be honest man you'll need a filter in it to get it running at all - it will be too lean without one. My race bike uses 120s and a full exhaust and uses std airbox and filter.

No filter will be nasty

not disputing your advice .guys like your good self have been about these bikes longer than i and know them inside out . will get a filter and some pics up need the exhaust identified also then get some jetting advice. it was running as track bike set up as you say lean . what does the hrc box do ignition wise if it advances the timing and coupled with lean running could that have damaged the valves and seats

[CMSMJ1]

The common HRC box for NC30s basically allows you to run no speedo. If you whip a plug out and check it you'll orobably see it is very white (if it was actually running) or very black (as it never fired and was flooded)

Valve seats and pistons get knackered with consistent and sustained ean running - but to be fair, I imagine that without a filter it would not even run well enough to knacker them. lapping them in is a time consuming ballache but satisfying.

My experience was that when I built my bike I raced it at Cadwell - first race was great but I managed to convince myself the bike was running rich and so being the clever dick I am, I removed the filter for the next race. The bike just about started and when I got to setting off in the warm up lap I knew I had made a big mistake. The bike would not rev or even think about it. I crawled about the warmup and pitted - it was totally unusable.

[Dynamohum]

carb rubbers arrived yesterday have cleaned carbs and re assembled them took me 2 hrs to get them back on fitted a used set of er9s and a used filter cranked it over and it showed signs of life before battery died . charged battery up and will get round later today pretty optimistic it will run in some fashion then take it from there.

the hrc box does seems a waste of the kind of silly money used ones go for if thats all it does then i suppose it does the same job as the £8 speedo resistor kit rick sells then

[Dynamohum]

hurrah it runs ! got it running today with some assistance from jump leads from the car battery. broke the golden rule had to use a little throttle as well as full choke as cmsmj1 rightly said its probably running mega lean even with a filter in but will sort out fuelling at a later date. but it revs freely once warmed without any spluttering etc i have posted some pics in members bikes section . next stage is to drop motor from frame now i know its a runner, it has a broken stud on front left cylinder which is blowing and another on rear manifold also figure its easier done with motor out of the frame.