NC23 - bogging down from idle

[Wozza]

Don't get it on a dyno until you've got it as sorted as you can. Your starting point should be making sure everything is put back to the standard setup. This means checking the float heights, reset the pilot screws MAKING SURE each one has its rubber o-ring, spring and washer in the correct order. Replace the o-rings even, they are likely to be original 22-year-old ones. Check the needle heights - iirc there should be no shims for standard height. Check the diaphragms, check the carb rubbers for seal. Most of all GET SOME 115 MAIN JETS! Even if yours are Dynojets you will probably want at least 112s. Then balance carbs.

When you've got everything as it should be as standard, then we can make some progress.

[The Novice]

i have done all those things, although i do need to set the pilot screws back to standard after i leaned them off a bit. Oh and i sealed the carb bowls with hylomar blue, works well so no need for new o rings at the mo. if i had a spare £60 i would get some as resealing every time i open them is a ball ache.

I did wonder whether i should put 115's in before getting it on a dyno or just see what Mr dyno said, i am just going to get a power run and fueling graph. I have been out on the bike since i posted this original msg and it behaved much better, also felt pretty strong and revved well so i was even more confused about the jets after that - anyway.

(For anyone who hasnt read the other post, my bike is an rrj, but has 110 main jets in it. Haynes says it should have 115's hence Wozza's advice....

when i get a spare hour i will get them off again to replace the jets to 115's. Where is the best place to get them from?

[Cammo]

Oh and i sealed the carb bowls with hylomar blue, works well so no need for new o rings at the mo. if i had a spare £60 i would get some as resealing every time i open them is a ball ache.

Rick Oliver (member on here) sells o-ring replacements for about 7 quid a set of 4 for the nc30 carb float bowls (same fitment as nc23), they work well.

[Wozza]

Sorry, couldn't remember what you had/hadn't done. I meant the o-rings on the pilot screws - a DIY shop selling o-rings individually should have some to match. Graeme should have some second hand 115 Keihin jets.

[The Novice]

Thanks for the tip on the float bowl o rings, got a set from rick and just waiting on some dyno main jets as recommended and supplied by Graeme France. Will try and change the pilot o rings too. Got new iridium spark plugs to fit so all will be new. Anything else prior to the dyno? Ps I am going to return the pilot screws to factory settings 2 1/2 turns and balance the carbs again before i go. Should I b checking the valve clearances? If so how hard a job is it? Carbs and tank are off at the moment whilst I wait for the main jets to arrive.

[The Novice]

Well I have now
- changed the plugs.
- checked the valve clearances and changed a few shims so they are right.
- Fitted new o rings to float chambers - cammo, great tip, they fit well, no more leaky carbs for now!
- checked each pilot screw, 1 of them had no o-ring or washer so i replaced them with items i spotted in Halfrauds and also changed the other 3 o-rings for peace of mind.
- replaced my 110 main jets with jets as recommended by Graeme France. I think they are dyno's 112.
- pilot screws returned to factory setting (one of them has been part rounded off by some ejut so i need a new pilot screw in time but it is useable for nowand its set)
- Forgot to check needle heights....
- removed the little baffle thing out the exhaust
- Adjusted the rear shock to make it a bit firmer for me (i am a bloater)
- Put it all back together.....................and

well, i managed to get half hour last night to go out on it, idle needed adjusting as it was idling at approx 1800 but i left it alone at first as i just wanted to ride it, much more powerful than it was, no hesitation at all through the rev range which it did before, revs v strongly all the way to the red line.....ride was firmer and felt good all round !! I stopped at my dads for a chat, adjusted the idle back down to about 1300- 1400 and set off home. Again all good BUT - stopped at a few sets of lights and noticed if i blip the throttle from idle, just slightly but a quick snap on the throttle, it does still die on me.

I think i am just going to have to live with it for now or up the idle (it didnt cut out when it revved higher) as i dont know why it does it, suppose i can mention it at the dyno when i get round to taking it! anyway....the rest of the bike is now awesome, pulls like a beast (i have never riden a faster bike), brakes are strong and firm (braided lines) handles well and most of all the crud and grime on the chain and swing arm has gone which must give it an extra 1hp !! I felt like streethawk last night............

thanks all for the tips

[Wozza]

Good stuff - sounds like you might want to dial in the pilot screws, might need leaning off (screwing in).