tickover problems

[Ethelred]

The engine's been rebuilt, not by me, sometime ago I think and done minimal miles since. The magneto has been reconditioned. She starts fine but will only tickover with a little bit of choke. I've fitted a new monoblock and pancake filter, jetting is standard. My first thought was an air leak so I refitted the carb with a smear of silicon over all the gaskets, no difference. I've adjusted the pilot screw every which way but still only get a smooth tickover with a bit of choke. I've checked the float level using that wonderful tip with a piece of tube on the primary jet and it's spot on. The plugs indicate that it's running rich, they're black. New plugs, Champions, and non-supressor caps.
The first little test round the car park, up to 2nd gear, she pulls like a train. Sounds really rorty, not many baffles in the new exhausts methinks. I did wonder if it could have been rebuild with higher compression pistons and go-faster cam, though it's an iron head. Do the road rockets tick over smoothly? Do freshly rebuilt engines take a while to bed in and tick over smoothly? I'm grasping at straws now. Any suggestions welcome.

[A10 JWO]

Mine has a newly built engine. Ticks over nicely until I put a set of new Champions in the old girl. Gone back to NGK as per the Haynes bible, now fine.

Colin

[metalflake11]

Yup! Rockets do tick over smoothly. Mine won't run well on Champions either.
 I think this might well be a semi blocked pilot jet. Clean that out and run the engine up to temp on the road. Only then will you get a decent idea on the state of your mixture. Stand by for advise on plug chops.

[mayes]

Hi just to point out I had problems with champions with my other brit made bike  the champions they problemmatic at the higher rev level went to NGK
and problem solved.

Thanks John

[Ethelred]

Well after a month of decorating I finally got back to the bike. Amazing how many theories you can come up with as you emulsion. Carb stripped and blown through. New carb gaskets hylomared in. Then the bl**dy kick start return spring broke. Replaced that, new NGK plugs. Now ticking over reasonably well so off for the first ride! The choke lever came loose and kept slipping on, the front brake was binding then seized completely and she wasn't charging. Minor inconveniences. Disconnected the brake and rode home, operating the throttle whilst holding the choke open with your thumb is a useful life skill. All in all a typical first proving run. Thanks for the support, these problems can throw you into the pit of despondency, getting any advice at all helps you feel less alone.

[Triton Thrasher]

Did you remove the pilot jet to clean it?

[Ethelred]

Yes, cleaned everything in thinners.

[wilko]

And did you clean the tiny pinholes either side of the slide.

[Ethelred]

An update:
Like the wise man said, most carburation issues turn out to be electrical.
Having tried every permutation of jet sizes, needle position, a new carb and refitting several times, it was still running like a dog on low throttle openings, hunting and surging.
Maybe it's something to do with the ATD I thought, and sure enough the springs on it were very weak. Interesting to note the difference between the cheap ones on ebay which look like something out of a biro, compared to the real thing from a reputable source which looks engineered. What really caught my eye though was the quarter inch of end float in the magneto, and then the points held on with a squashed copper washer and buckled. This bike came from a dealer, whose name will be made very public if he doesn't get in touch with me soon, and had supposedly had a presale check and service plus a recon magneto! I think not.
Today I fitted a recon magneto from Priory Magnetos, excellent service. Isn't the timing on these bikes a pain in the idiot. Still thanks to reading some excellent posts from folk on here I got it on the 5th attempt. Set to 5/16 BTDC which seems to be the consensus for a gold flash. Nobody said whether you should use the blue papers or the green ones though...
And then after a few kicks she runs, a beautiful measured beat on tickover - music to my earholes.

[muskrat]

Great to hear mate.
Never believe a car (or bike) salesman or politician.
Use the green ones AFTER you set the timing .
Cheers