tick over problems

[paulwolf]

I have a 1993 Commander with a tick over problem,I start the bike up with no problems,once the engine is warmed up it revs at about 800rpm,if i then ride for a couple of miles or more and stop for any reason the revs are about 1,500 so i then return home to try to adjust the tick over, i turn the engine off restart it and it revs at 800 for as long as i run it with the fan cutting in & out and engine temp at 85.Anyone know what it is?Cheers Paul

[Howell]

Hi Paul, Which ignition unit to you have ? The original Boyer unit on my Commander was prone to behaving like this, something I put down to the retard thermistor (mounted by the water temp sensor) cooling sufficiently to advance the ignition.The Norton motors digital unit, on some, but not all machines can cause the engine to stick at 2,000 RPM. This can be counteracted by pulling the engine down using the brakes, which will drop the engine to it's usual tick over. Tricky in traffic!I have one of these units on my Interpol, two other members of the club, Wayne and Brian - local to me - have also experienced the same symptoms. I have fitted one of Graham's units (Startright Motorcycles) to my Commander with complete success, which was a bit of a puzzle as these are made by Julian at Minimag who also made the Norton units.Happily, Julian is able to re-program the the ignition boxes to the same spec. as Startright's units for a very reasonable cost.Regards,Howell

[paulwolf]

Hi,Thanks for the advice,i don`t know if i done the right thing but i screwed in the left engine idle adjustment screw one turn and the bike now ticks over ok.Thanks paul

[gripper]

You may find your strange tickover problems are caused by a air leak in the induction pipe from carb to engine. In my case, an engine that would start reasonably and then increase in speed to tickover at 2000rpm was caused by the thin vacuum pipe that sucks the petrol tap open. It had become displaced and then melted against the engine. The question was then, why was petrol still getting past the non vacuum fed tap? Who knows? maybe the working parts of my tap are not working parts. The give away in my case was that, when trying to pull away with the high revving engine, there was no power pecause despite the high revving engine, the throttle was colsed. It's worth carrying a length of vacuum pipe and two of the little rubber end boots in your "go kit" they are available from old car accessory shops as distributor advance/ retard tube. I must say I was dead smug when, after I had identified my snag at the NW200 just last week, I fished the spare tube out of my secret stash of bits.