down and starting again it would not tick over at all so back to square one.I tried giving it a really good run and after a marathon trip of over 300 miles when stopping at junctions it was racing at 1500 RPM. I wondered about air leaks but engaging first gear and letting out the clutch with the brakes on the engine pulled like a train, had it been an air leak surely the engine would slow down, anyway in desperation I checked all the usual suspects such as air leaks around the induction tubes etc etc but without success.I trawled the forum and picked up on several good ideas, all tried without success, spoke to GW at Startright who suggested a good run but tried that already, then began to consider Graham’s suggestion at disconnecting the thermistor setting the tick over and reconnecting.I had already checked the thermistor with a hair dryer and my meter so knew it was OK (by the way I have an original Boyer on this bike) so disconnecting the thermistor I ran the engine and let it warm up to normal temperature set the tick over to a very steady 500 RPM and was very pleased with the result, with the engine still nicely ticking over I reconnected the thermistor when the engine speed immediately dropped down only to quickly recover back to the steady tick over.Since then when cold it starts OK but is not happy until it has warmed up a bit (it has always been like this) when it then settles to a steady tick over, when the cooling fan cuts in the engine speed barely moves, the tick over is adjustable over a wide range with the screws in the induction tubes and will always come back to a tick over of my choice, the engine responds readily to the throttle and pulls well through the gears.So what was the reason for the crap tick over? something weird with the Boyer? just one of those things? did disconnecting and reconnecting the thermistor reset the Boyer? I would like to know as it had me chasing my tail for a few weeks.Perhaps it will be another “mystery of the sea” as often said by my colleagues at work, but I do not care, I have my wonderful Commander back and can’t wait to get back on the road once this awful weather has finally sorted itself out.TonyTick Over Mystery
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Anthony Duffield
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- Posts: 320
- Joined: Sun Aug 11, 2013 8:13 am
Tick Over Mystery
Having rebuilt the Commander engine I set about running it in all seemed ok except the tick over, which I could not get right, it would not tick over when cold, when hot I could get a decent tick over but it was not steady and when the cooling fan cut in the speed dropped to an almost stall. Letting it down and starting again it would not tick over at all so back to square one.I tried giving it a really good run and after a marathon trip of over 300 miles when stopping at junctions it was racing at 1500 RPM. I wondered about air leaks but engaging first gear and letting out the clutch with the brakes on the engine pulled like a train, had it been an air leak surely the engine would slow down, anyway in desperation I checked all the usual suspects such as air leaks around the induction tubes etc etc but without success.I trawled the forum and picked up on several good ideas, all tried without success, spoke to GW at Startright who suggested a good run but tried that already, then began to consider Graham’s suggestion at disconnecting the thermistor setting the tick over and reconnecting.I had already checked the thermistor with a hair dryer and my meter so knew it was OK (by the way I have an original Boyer on this bike) so disconnecting the thermistor I ran the engine and let it warm up to normal temperature set the tick over to a very steady 500 RPM and was very pleased with the result, with the engine still nicely ticking over I reconnected the thermistor when the engine speed immediately dropped down only to quickly recover back to the steady tick over.Since then when cold it starts OK but is not happy until it has warmed up a bit (it has always been like this) when it then settles to a steady tick over, when the cooling fan cuts in the engine speed barely moves, the tick over is adjustable over a wide range with the screws in the induction tubes and will always come back to a tick over of my choice, the engine responds readily to the throttle and pulls well through the gears.So what was the reason for the crap tick over? something weird with the Boyer? just one of those things? did disconnecting and reconnecting the thermistor reset the Boyer? I would like to know as it had me chasing my tail for a few weeks.Perhaps it will be another “mystery of the sea” as often said by my colleagues at work, but I do not care, I have my wonderful Commander back and can’t wait to get back on the road once this awful weather has finally sorted itself out.Tony
down and starting again it would not tick over at all so back to square one.I tried giving it a really good run and after a marathon trip of over 300 miles when stopping at junctions it was racing at 1500 RPM. I wondered about air leaks but engaging first gear and letting out the clutch with the brakes on the engine pulled like a train, had it been an air leak surely the engine would slow down, anyway in desperation I checked all the usual suspects such as air leaks around the induction tubes etc etc but without success.I trawled the forum and picked up on several good ideas, all tried without success, spoke to GW at Startright who suggested a good run but tried that already, then began to consider Graham’s suggestion at disconnecting the thermistor setting the tick over and reconnecting.I had already checked the thermistor with a hair dryer and my meter so knew it was OK (by the way I have an original Boyer on this bike) so disconnecting the thermistor I ran the engine and let it warm up to normal temperature set the tick over to a very steady 500 RPM and was very pleased with the result, with the engine still nicely ticking over I reconnected the thermistor when the engine speed immediately dropped down only to quickly recover back to the steady tick over.Since then when cold it starts OK but is not happy until it has warmed up a bit (it has always been like this) when it then settles to a steady tick over, when the cooling fan cuts in the engine speed barely moves, the tick over is adjustable over a wide range with the screws in the induction tubes and will always come back to a tick over of my choice, the engine responds readily to the throttle and pulls well through the gears.So what was the reason for the crap tick over? something weird with the Boyer? just one of those things? did disconnecting and reconnecting the thermistor reset the Boyer? I would like to know as it had me chasing my tail for a few weeks.Perhaps it will be another “mystery of the sea” as often said by my colleagues at work, but I do not care, I have my wonderful Commander back and can’t wait to get back on the road once this awful weather has finally sorted itself out.TonyRe: Tick Over Mystery
Tony,I would just rejoice in the fact that you have cracked the tickover!I would say that what you experienced (especially after rebuilding your engine) is quite normal! Your engine has beddeddown and everything else has settled down.Put all the "fixes" into the memory bank for future reference.