Good News/Bad News.

[woodsman]

Bad News first, think my starter clutch is goosed. Sometimes when the bike is started the bike makes a nasty crunching noise, not always. I am guessing this is the starter clutch not engaging properly. Seems like an easy enough repair, just wondering what goes wrong in the starter clutch? Is it worth trying a second hand one and are they all the same RVF,NC20'S?

Good News,is that even with the dodgy starter clutch the bike started ,and held a steady idle after doing the valve clearances and all the work suggested in the carby thread. The only thing i noticed was that when the bike was revved it would drop slightly below idle and then recover. Does this mean it is running slightly rich or lean?

p.s How are these little bikes to bump start?

Thanks, Sean.

[Neosophist]

Bad News first, think my starter clutch is goosed. Sometimes when the bike is started the bike makes a nasty crunching noise, not always. I am guessing this is the starter clutch not engaging properly. Seems like an easy enough repair, just wondering what goes wrong in the starter clutch? Is it worth trying a second hand one and are they all the same RVF,NC20'S?

Good News,is that even with the dodgy starter clutch the bike started ,and held a steady idle after doing the valve clearances and all the work suggested in the carby thread. The only thing i noticed was that when the bike was revved it would drop slightly below idle and then recover. Does this mean it is running slightly rich or lean?

p.s How are these little bikes to bump start?

Thanks, Sean.

Easy enough to bump start.

Basic question but are the carbs clean and float heights / mixture screws set right?

Firsly make sure the system is all together properly, there are no airleaks on the carb rubbers (can be detected by spraying some easy start around the rubbers, change in RPM means a leak)

That the vaccum hose for the tap isnt leaking air and all the carb balance screws are in place and the airbox is seated properly with a clean airfilter.

Once everything is correct you can tune the mixture. Trying to tune with dirty carbs / air leaks will never get a good tune.

Heres a little note from factory pro:s carb tuning guide.

NOTE: A rich problem gets worse as the engine heats up.
If the throttle is lightly "blipped" at idle, and the rpm drops below the set idle speed, then rises up to the set idle speed, the low speed mixture screws are probably set too rich: try 1/2 turn in, to lean the idle mixture.

NOTE: A lean problem gets better as the engine heats up.
If the throttle is lightly "blipped" at idle, and the rpm "hangs up" before dropping to the set idle speed, and there are no intake leaks and the idle speed is set at less than 1000 rpm, the mixture screws are probably too lean: try 1/2 turn out, to richen mixture. Be sure there are no intake leaks and the idle speed is set at less than 1000 rpm!

Hope you get it sorted.

Out of curiosy what are you mixture screws and float heights set at?

[woodsman]

Crabs are clean. Just changed out the original 110 jets for 110/115 combo, raised needle, drilled slide, as per carby guide. As the bike ran well before i left the floats, only checking they were free. Only non standard is a dual foam layer in the air box, no air filter.
Don't think it's far off but it's hard to say without a good road test. Might just try leaning out the mixture a tad, screws are set at 2 turns out just now.

[woodsman]

Should read 115/118 for jets.

[Cammo]

You're running standard sized jets and stock pilot screw setting with a foam air filter? That will be a problem.

You'll need to adjust your pilot screws richer to suit your foam air filter. Try an extra half turn out, if it improves fine tune from there.

Have you ridden the bike with the foam filter fitted? I'd imagine those sized jets won't suit the filter very well. If you have issues it's best to put a standard air filter back in (better than foam IMO).

[woodsman]

Bike never had standard filter in it when i bought it last year. It ran fairly good when i got it apart from a flat spot lower down in the range .Will try and get it out for a spin and see how it goes.
It's been lying up since the end of summer last year when i decide to do the valve clearances and do the mods recommended in the carby guide. Went up to the shed last night and it started first tip of the button on full choke, holds a steady idle when the choke is off.
Anyone know about the starter clutches, are they the same throughout the nc,rvf range?

[woodsman]

Had the bike out yesterday and it ran fine. Pulled well all through the range and didn't have the bad flat spot that was previously in the lower range. Starts on the button from cold and hot. In relation to it running rich or lean i think i will just rack up some miles and see how the plugs are then.
Anyone know if the starter clutches can be swapped in from other models? rvf? nc?
Thanks, Sean.

[magg]

Outer ring of starter clutch is different P/N between NC30 and NC35, result of different timing requirements, so only some bits of an NC35 starter clutch will suite an NC30.

Some of the high wear bits of the starter clutch are the same P/N for NC30 & 35 and can still be sourced from David Silver, so depends on which parts of your starter clutch are broken.

[Cammo]

In relation to it running rich or lean i think i will just rack up some miles and see how the plugs are then

If it's lean it generally won't run well to redline, if rich you'll just be burning more fuel than necessary.

Forget looking at the plugs on a 4-stroke, waste of time unless you do a plug chop from 3rd+ gear at high revs straight before taking the plug out (not convenient!). Best to get it on ea dyno if you have any doubts.