New Member +Rough Idle & Control Levers

Thanks for your replies. I have the workshop manual, not Haynes. Is it worth having both?

On clutch lever adjustment, the workshop manual says:

C35.8 "Adjust the clutch cable at the control to provide 3/16" to1/4" free movement between the cable outer and adjuster".

I assume the "control" means the clutch lever on the handlebar? My cable outer has no movement relative to the adjuster (the slotted knurled ring, where the cable enters the lever housing). My clutch lever now has a very small amount of movement, before I feel tension. When I got the bike, it was set with the adjuster 2/3rds in. This caused clutch slip at higher loads. I unscrewed the adjuster, so It is now half way in and doesn't slip. Still a little stiff, but I don't know if that's normal. 

Do I need to remove the tank? Is it OK to leave it on, disconnect the fuel lines at the tap and empty it through the taps, before removing each tap to check them? Will I need new sealing washers, or ok to re-use?

Thanks, Martin

Things seem to be going south! The hesitation problem has worsened.

The petrol tank looks ok. Tap filters are clean. They empty with a steady stream, not a gush, not a trickle. I did 80 miles yesterday. The bike hesitated a couple of times early on and cleared and ran well. It stalled 5 miles from home on tick-over, then ran fine again.

Today, I thought I'd warm it up to adjust the idle (Amal 34mm single carb). It was lumpy warming up on the drive, than stalled as I changed from 1st to 2nd (100yds in). Restarted, but wouldn't tickover without throttle, so I turned round. Stalled again when I pulled in. Wouldn't restart. Plus, one backfire, when starter motor was turning over. Nearly fell over at that! Went for a cuppa and regathered.

The plugs were both sooty. I cleaned them and set at 25thou. I adjusted the idle (throttle adjuster screw) and it restarted ticking over at 2000rpm. Adjusted the pilot air screw and it increased revs and ran smoothly.  I reduced the idle revs, but it gets uneven below about 2000rpm and stalls below 1700rpm, even with the pilot air screw out 9 turns. The engine was warm by this point.

The air filter (RGM K&N style) looks clean enough. The carb to intake rubber seal looks tight and sound. I have a very slight leak (light puff at each pulse) at the LH exhaust header, which is as tight as it will go. No fuel leaks.

Dirty / blocked carb? Any other suggestions / any wisdom and where to start, gratefully received. I did forget to turn on the fuel taps a couple if times yesterday. It ran, coughed and stopped. I also started yesterdays run forgetting to turn the choke off, until 4 miles in. Could these have caused any problems?

Appreciate any help.

Thanks, Martin

It has Boyer ignition, not sure of model. Reference to fitting new Boyer pick ups in 2013. The Amal is a 2900 34mm mk2 (model 2934), fitted new in 2013 (from RGM). It had a replacement pilot jet (20) and cold start plunger last year.  It has a 106 needle jet, 3.5 slide, 2A1 needle, on 3rd mid position, 280 main jet, 20 pilot jet (originally a 15), 50 choke jet, K&N RC-1900 air filter (57mm round). A range of jets and settings were tried in a table showing results. So, I think this was a suitable set up. HT leads (wire type) replaced last year. Timing checked Dec 2019.

Test ride was short from cold and OK. I don't know anyone with Norton knowledge. I relied on my own experience.

The mileage has been steady at 150 to 500 miles p.a., so stood most of its recent life. It has an RGM brake disc, calliper and hydraulic 'upgrade' installed, which may have affected the position of the lever to the bars. Interesting the pre-mk3 levers are different, it has a slightly different profile to the clutch lever. I will look into it.

Clutch: I haven't looked inside the case, the cable enters the case in the right line and has smooth curves back to the lever. Lubrication has helped, and adjustment at the lever. It is acceptable now. I think the diaphragm effect was new to me and felt wrong, initially. It did not slip on Monday and gear selection was easy. Hoping that one's sorted. Don't plan on 90mph plus.

Battery is coming up to 4 years. Taking charge fine on my tender.

Not belt drive, has a Boyer Bransdon powerbox (12v, single phase).

Tyres are 2012 Dunlop TT100s. I quite like their feel, so will go with the same. I will replace as early priority in the next couple of weeks, as soon as I can trust it to get me there. No signs of rubber deterioration, rear a little squared off.

I've experienced good and bad workmanship in the past. The records of their work runs to 40 odd pages + parts receipts and 122 photos. Suggests some care and knowledge.

Hope this helps? Appreciate your assistance.

Just to close this out. Having flushed the tank, cleaned the carb and fresh jets, still not running. Re-checked the plugs, no spark from one of them. Replaced both and it starts fine and warmed up, adjusted the air screw and idle. I've got it ticking over smoothly at 1100 to 1200 rpm. Happy!

Needs a test ride. :-)