
Two Dead Cylinders??
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Two Dead Cylinders??
Hi Gang, Need a bit of advice here, I have bought a very tidy 1982 Honda CB 750F2, Bol d Or, I thought riding it home that the carbs were badly out of sync but on investigating I find that the two nearside pots are not firing, i.e. no spark at the leads. The bike has been standing unrun for some time, (which is why the 2nd left carb is leaking I reckon) Anyway any help, advice welcome. Cheers. John 

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Re: Two Dead Cylinders??
Didn't read your 1st post properly.gempip wrote:the two nearside pots are not firing
If it isn't the plugs then:-
It's usual for the outside two and inside two pots to run from a coil each and there's a lazy spark in the pot that isn't on the compression stroke.
Unless I'm wrong abut the way this bike works then both the coils must have been good as proved, but it's odd that one spark works and the other doesn't. Does this bike's ignition sequence work as I think?
Perhaps the low tension side is at fault, points or pickups?
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New plugs first, no point in pissing about, they can fail under compression.
Is there a spark at the plugs now?
If so replace and check if the suspect headers are getting hot? If not spray easy start direct into the carb inlets of those not getting hot. If they then fire and get hot you know its fuelling and time to check if those carbs are getting juice by removing drain plugs.....
Is there a spark at the plugs now?
If so replace and check if the suspect headers are getting hot? If not spray easy start direct into the carb inlets of those not getting hot. If they then fire and get hot you know its fuelling and time to check if those carbs are getting juice by removing drain plugs.....
Trumpeteer wrote:New plugs first, no point in pissing about, they can fail under compression.
Is there a spark at the plugs now?
If so replace and check if the suspect headers are getting hot? If not spray easy start direct into the carb inlets of those not getting hot. If they then fire and get hot you know its fuelling and time to check if those carbs are getting juice by removing drain plugs.....
Hi, Thanks for all that, The situation now is that I have got it down now to one potheader is cold after firing up and on that one (a) the plug dosnt seem to spark (although they are supposed to be new plugs and the coil/s has been tested as positive) and the carb that feeds that one is flooding all the time. So I will try another plug and see where we go from there. I suppose the bike being stood for a long time before I got it dosnt help.

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Red 1995 VFR750 - I luvs it.
Red 1995 VFR750 - I luvs it.