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CB350/400 / Odd spark problem
« on: January 19, 2020, 03:57:45 PM »
I've think I sorted it .......but its a weird one (Northy what hell are you talking about !! )
Well for few weeks I've had this problem with the special 400/4 . After about 8/10 miles it would lose number 2/3 cylinders with no spark.The more you used the revs the less miles you did, so heat related? however wait 5 minutes and it runs Ok on all four, for about 4-6 miles.
This was PIA as it fixed it self before you got to testing things.
But Coil I hear you say !
So replaced the new DS one with an old one ..same result
Replace both coils and leads/cap from my other 400f ...same result
Swapped plugs ...same result
Replaced the condensers from my other 400f, clean points (again) ...same result
Checking wiring/connecting ...all seem ok
Not water related as only used in the dry
Thinking of making up a new wires from the points to coil or pleading for help on the SOHC forum
Then today I had a thought (yes the 2 brain cells clicked in) this followed yet another run of 10 miles, then it goes onto 2. What haven't I changed and what have I changed. As the other 400/f with the swapped out part runs fine.
Well it took 1 minutes to fix it ......I managed 22 miles with not even a misfire , lots of revs etc (by which time it was getting colder )
The possible culprit .....
[ Guests cannot view attachments ]
I don't know why but replacing this with the standard chrome points cover sorted it. I had fitted it a few months back.
Its not clearance issue but the ally one does get a lot warmer then the chrome one .This could point to something (points/condenser) breaking down under heat. The final test is refit the ally one and see if I can make 22 miles. (way too cold now for that )
So I think its sorted but its an odd one .....anyone had issues like this ?
Well for few weeks I've had this problem with the special 400/4 . After about 8/10 miles it would lose number 2/3 cylinders with no spark.The more you used the revs the less miles you did, so heat related? however wait 5 minutes and it runs Ok on all four, for about 4-6 miles.
This was PIA as it fixed it self before you got to testing things.
But Coil I hear you say !
So replaced the new DS one with an old one ..same result
Replace both coils and leads/cap from my other 400f ...same result
Swapped plugs ...same result
Replaced the condensers from my other 400f, clean points (again) ...same result
Checking wiring/connecting ...all seem ok
Not water related as only used in the dry
Thinking of making up a new wires from the points to coil or pleading for help on the SOHC forum
Then today I had a thought (yes the 2 brain cells clicked in) this followed yet another run of 10 miles, then it goes onto 2. What haven't I changed and what have I changed. As the other 400/f with the swapped out part runs fine.
Well it took 1 minutes to fix it ......I managed 22 miles with not even a misfire , lots of revs etc (by which time it was getting colder )
The possible culprit .....
[ Guests cannot view attachments ]
I don't know why but replacing this with the standard chrome points cover sorted it. I had fitted it a few months back.
Its not clearance issue but the ally one does get a lot warmer then the chrome one .This could point to something (points/condenser) breaking down under heat. The final test is refit the ally one and see if I can make 22 miles. (way too cold now for that )
So I think its sorted but its an odd one .....anyone had issues like this ?