Wallie Posted July 30 Report Posted July 30 So I've been trying to get to the bottom of a problem I'm having with the NC30. On a cold start, it just won't rev cleanly. It starts on the button without fuss (full choke and no throttle) although it does seem fluffy to start with. Generally it seems to sit at 2k before rising to 4k, almost as if a cylinder or two isn't firing and then as it gets warmer it comes on - although it doesn't sound like its missing. After leaving it for a few minutes to warm up, any touch of the throttle will bog. It's never quite died, but near enough tries to. Now for the weird bit - with some careful throttle and slipping the clutch to get going, it's grand. Once it's moving, it's feels great. Techincally it's 99% usable, but that niggle is bugging me. So far I've: Had the carbs off and cleaned everything multiple times inc jets, choke circuit (as good as I can) They are definitely seated properly every time with new rubbers. Floats checked - two are new. (this is the bit I'm least confident I've done correctly) Carbs balanced New seals on the mixture screws and different positions ranging from 1.5 turns out to 3 turns out. (recommended is 2.25-2.5 out) Anything I've potentially missed? Quote
El Gringo Posted July 30 Report Posted July 30 My NC23 is exactly the same, it's like it's not quite there on 2 until it's fully warm. Just slightly fluffly as you describe I've always put it down to having absolutely tiny pilot jets Quote
TLRS Posted July 30 Report Posted July 30 Maybe it’s struggles to burn fast. 0nce it does, raises the revs as it’s earlier with the push? Quote
Wallie Posted July 30 Author Report Posted July 30 48 minutes ago, srad34 said: What’s the tick over set at? 14 minutes ago, TLRS said: Maybe it’s struggles to burn fast. 0nce it does, raises the revs as it’s earlier with the push? Tickover is at 1500. I have noticed that if I do increase it anymore to 1750 say it seems to start hunt. 43 minutes ago, El Gringo said: My NC23 is exactly the same, it's like it's not quite there on 2 until it's fully warm. Just slightly fluffly as you describe I've always put it down to having absolutely tiny pilot jets Yeah It's exactly that. It's not the end of the world as fundamentally it runs nice when its warm, but a bit annoying. 1 Quote
El Gringo Posted July 30 Report Posted July 30 1 minute ago, Wallie said: Yeah It's exactly that. It's not the end of the world as fundamentally it runs nice when its warm, but a bit annoying. Indeed, I've wondered if it's a generic Honda thing too, the CB600 i'm currently tootling about on is the same and seems to take an age to warm up before it fully chimes in. Quote
ssray Posted July 30 Report Posted July 30 My zzr11 was kinda the same, start up, in gear clutch out and stall, start and try and keep the revs up( sometimes I leave for work at 0230) and slowly up the not very steep slope of the driveway. I went through the carbs, bought a ultrasound cleaner, new plugs, fuel filter etc. The pilot jets were cleaned multiple times, I could see light through them as per what everyone said. I looked up new pilot jets by googling the spec on the side and bought 4 new ones for about £25. Using a unsafe method of work (funnel with fuel in pushed into the fuel hose) After a couple of top up's the thing started , ran well, pulled away from cold , this was about a year ago and I only get similar after leaving it standing for a few weeks. Quote
srad34 Posted July 30 Report Posted July 30 Is it jetted properly for the set up you have, exhaust, filter etc? Quote
Wallie Posted July 31 Author Report Posted July 31 10 hours ago, srad34 said: Is it jetted properly for the set up you have, exhaust, filter etc? Yep, 118/120. Standard airbox/filter. The only change from stock is the bellmouths have been trimmed. 15 hours ago, ssray said: My zzr11 was kinda the same, start up, in gear clutch out and stall, start and try and keep the revs up( sometimes I leave for work at 0230) and slowly up the not very steep slope of the driveway. I went through the carbs, bought a ultrasound cleaner, new plugs, fuel filter etc. The pilot jets were cleaned multiple times, I could see light through them as per what everyone said. I looked up new pilot jets by googling the spec on the side and bought 4 new ones for about £25. Using a unsafe method of work (funnel with fuel in pushed into the fuel hose) After a couple of top up's the thing started , ran well, pulled away from cold , this was about a year ago and I only get similar after leaving it standing for a few weeks. That's not a bad shout, for the sake of it I might just replace the pilots and the two remaining floats while I'm there. 1 Quote
CMSMJ1 Posted July 31 Report Posted July 31 Have you got standard bell mouths? Have the floats been drilled, as was the fad back in the day? Needles standard? Numbers of washers under the needles? Quote
Wallie Posted July 31 Author Report Posted July 31 38 minutes ago, CMSMJ1 said: Have you got standard bell mouths? They've been cut down, although I'd have assumed this would only affect higher up the rev range. 38 minutes ago, CMSMJ1 said: Have the floats been drilled, as was the fad back in the day? Look undrilled to me. 38 minutes ago, CMSMJ1 said: Needles standard? Numbers of washers under the needles? Standard as far as I'm aware. 2, .5mm washers. Quote
CMSMJ1 Posted July 31 Report Posted July 31 There's a slim chance I've got some bellmouth spares and I'm sure I've floats, but fucked, that can check the config on. I think a the lifted needle was a single extra washer so you might be slightly richer at idle than std. If it works when hot it would suggest too rich if my carb voodoo is remembered. Mine is at home but I've still not managed to put the standard tail and rewire it so fucked if I can test it and give you real feedback Quote
Wallie Posted July 31 Author Report Posted July 31 4 minutes ago, CMSMJ1 said: There's a slim chance I've got some bellmouth spares and I'm sure I've floats, but fucked, that can check the config on. I think a the lifted needle was a single extra washer so you might be slightly richer at idle than std. If it works when hot it would suggest too rich if my carb voodoo is remembered. Mine is at home but I've still not managed to put the standard tail and rewire it so fucked if I can test it and give you real feedback If you've got the bellmouth's going then let me know how much and I'll have them off you. It is just the 1 extra washer on the needles, basically followed the guide during the carb setup along with drilling the slides. Man maths is taking over, going to give RO a bell and get some new pilots, floats ordered and enquire about a Ignitech and his fancy needles.... 1 Quote
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