misfiring

Previously wrote:

Previously wrote:

My Commando has developed a misfire sometimes at low revs, and runs fineup to 4k where it refuses to rev beyond that. I`ve cleaned the jets in the carbs but not the bodies,and checked and secured as many wiring connections as possible plus checked the ignition rotor,all seems ok. I`m wondering if the ignition powerbox(Boyer) is failing. Do these symptoms ring any bells with any members? P.s.My new (pattern)centre stand grounds on steep leanovers whereas the original didn`t. Cheers.Chris

Hi chris. REF IGNITION = In my experience of Boyer, the most common fault with them is a break in one of the wires as they enter the pick-up plate. Get the bike running and then wiggle each wire right next to the plate and see what happens. One may be broken even if you cant see a break in the sheath. They should be cable tied to the plate to prevent vibration. Failing that send the whole thing back to them for a test. They are very good and hav'nt ever charged me for testing. Not too hot on carbs, so will let others comment !

Hi Hans, yes the previous pickup plate packed up when the soldering joints fractured 2 years ago so the bike has been running ok for the last 2years till now. This current mis fire I initially suspected the plate (again) or blocked carbs. Thanks thus far anyway.

Chris

Previously wrote:

Hi Chris - I am just upgrading my ignition to Pazon in an attempt to get the electric statre to electric start reliably, so if you like I have a spare Boyer ignition set that is working properly that I have just taken off the bike, all yours for a moderate contirbution to the beer fund!

At least that may save you a total re-wire.

However in all conscience I have to tell you that I had precisely this problem with my last Commando when I put a bloody great big single carb on it - it revved up to 4,200 where it hit a brick wall, we diagnoised it on a dyno - it turned out to be fuel starvation in that case, but as it shows the same symptom might it be worth totally stripping the carb's?

Also it seems to me that Hans has made a very good observation, as the joints on the timing plate of this Boyer system have been re-soldered at some time to repair dry joints/replace wires.

Give me a shout if you want the Boyer.

Hi Jack thanks for the generous offer which I`ll hold off on till I`ve rechecked the (2 year old ) pickup for solder fractures. Yeah, the plate packed up 2 years ago so I did think of it AS A CAUSE BUT DISMISSED IT AS IT`S PRETTY NEW, I`LL GIVE IT A GOOD WIGGLE !

CHEERS

CHRIS

Previously wrote:

Previously wrote:

My Commando has developed a misfire sometimes at low revs, and runs fineup to 4k where it refuses to rev beyond that. I`ve cleaned the jets in the carbs but not the bodies,and checked and secured as many wiring connections as possible plus checked the ignition rotor,all seems ok. I`m wondering if the ignition powerbox(Boyer) is failing. Do these symptoms ring any bells with any members? P.s.My new (pattern)centre stand grounds on steep leanovers whereas the original didn`t. Cheers.Chris

Hi chris. REF IGNITION = In my experience of Boyer, the most common fault with them is a break in one of the wires as they enter the pick-up plate. Get the bike running and then wiggle each wire right next to the plate and see what happens. One may be broken even if you cant see a break in the sheath. They should be cable tied to the plate to prevent vibration. Failing that send the whole thing back to them for a test. They are very good and hav'nt ever charged me for testing. Not too hot on carbs, so will let others comment !

Hi Hans I took your advice to check ignition plate only to discover a dry joint on the yellow/black bullet snap connector. Let`s hope that`s it! Cheers. Chris

Previously wrote:

Hi Chris - I am just upgrading my ignition to Pazon in an attempt to get the electric statre to electric start reliably, so if you like I have a spare Boyer ignition set that is working properly that I have just taken off the bike, all yours for a moderate contirbution to the beer fund!

At least that may save you a total re-wire.

However in all conscience I have to tell you that I had precisely this problem with my last Commando when I put a bloody great big single carb on it - it revved up to 4,200 where it hit a brick wall, we diagnoised it on a dyno - it turned out to be fuel starvation in that case, but as it shows the same symptom might it be worth totally stripping the carb's?

Also it seems to me that Hans has made a very good observation, as the joints on the timing plate of this Boyer system have been re-soldered at some time to repair dry joints/replace wires.

Give me a shout if you want the Boyer.

Hi Jack I`ve discovered a dry joint at the bullet snap connector on the pickup plate,so, I hope that`s it. Many thanks for the advice and offer of the power box which I hope I won`t need now.