F1 Sport - Misfire and high tickover

[barney]

Dear Richard and all,I thought I'd start a new thread as it would make reading easier for anybody with a similar problem in the future.Having solved the overcharging problems on the F1 I now have the two other problems I mentioned in my previous threads.1) High Tickover. The tickover now fluctuates between 600 and 1200 RPM. The bike will often drop to 600 RPM at start up, but when I come to a junction or lights, it sometimes sticks at 1200RPM. I can get to the next set of lights and find it ticks over at 600 RPM again. The tickover is completely stable. Have I got a problem with my cold start circuit?2) Missfire. I'm getting an intermittent miss-fire at low revs. The bike will run fine for miles at high speed. Run fine in town for a short time, but after a couple of mins start to miss fire. A few blasts of the throttle will clear it out for a while, but within another 5 or 10mins it will start again. I've got new plugs and leads. Could the trigger unit have been fried by the over voltage problem? The bike is still running on the oil that came with it. Is it possible there a problem with the oil that is causing the plugs to foul up?Could problems 1 and 2 be related!!!Richard - hoping you can help!!!Kind regards,Barney.

[Richard Negus]

Barney,There say a picture is worth a thousand words - how about one of the igntion unit so I'm able to identify it, and not talk even more rubbish perhaps.No over-voltage problem will harm the ignition trigger ; those used by the original Boyer unit (and the Startright digital replacement) are inductive, generating a small voltage every time the step in the flywheel passes ; those used by the Norton digital are an automotive-type Hall effect switch powered by a regulated 5v supply from the ignition unit and sense the step by a change in magnetic flux.Your variable idle sounds more like adjustment of the idle air screws is required, or the cold-start mechanism on the carbs requires new O-rings, or the idle air pipes have an intermittent leak, or the throttle butterflies aren't balanced, or not closing properly, or ....It's easier to fix something that's broken than find an intermittent fault !Now to plumb in MiL's washing machine, hang her pictures, etc and all the other things that a dutiful SiL has to do to get more time for bike fettling / riding.R.

[barney]

Hi Richard,Sorry for the slow responce. I've been away for a couple of days.Here's some photos of the ECU (Or at least what I think is the ECU!!!)http://picasaweb.google.com/lh/photo/ji ... ctlinkIt's marked NM1002. Am I right in thinking this is the Norton Motors ECU? Does 1002 mean it was the second unit they built?!Could this be the cause of my missfire?Thanks again for you help.Barney.

[Richard Negus]

Hi Barney,I confirm that your bike has an NML digital igntion ; the number 1002 on the box indicates it was the second production unit. So far, I think a total of 64 have been delivered.Peter at NML has a box that he can loan you for test purposes; if you phone him, be patient if there's no immediate answer as he often goes out in the van delivering / collecting Commando parts work-in-progress. When stationary and the engine fast-idling at 1200rpm, can you engage first and, by engaging the clutch slightly, pull the idle down to a steady 600rpm ? If so it sounds more like the idle adjusters need screwing in slightly.R.

[Dell Boy]

Hello Barney. Don`t know if this is relevant with a Sport but on my F1 the heat ofthe engine in traffic vapourised the fuel in the supply giving an insoluble misfire & cutting out in town traffic. Because of this I sold the bike on. Derek.