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Sam GiftTue Jul-19-05 06:40 PM

  
"Dropping a cylinder"


  

          

Hi all, having a problem with the dommie (500 twin) when heading up long hills, don't particularly have to be steep but usually long, the old girl drops a plug and cylinder, typically the left side, and coughs and splutters accordingly....Any suggestions as to why this is happenning...she runs fine on all other inclines and surfaces...thinking maybe a timing issue ? ? ? Any advice greatly received

Cheers Sam

  

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RohanTue Jul-19-05 07:46 PM

  
#1. "RE: Dropping a cylinder"
In response to Reply # 0


  

          

Sam, since you only have one carb its not likely a carb issue - or both cylinders would have this problem ? How can you pick which side its on - this can be quite difficult/deceptive while on the move ?

So the candidates are
1- plug fouling or breakdown due to oil burning or air leaks.
2- breakdown of the ignition on one side. Could be plug cap, plug lead, maggie pickup (carbon brush) or carboning or problems with the slip ring in a certain position.

Anyone ridden behind you to see if it puffs oil smoke anywhere - particularly on acceleration (rings) or on the overrun (valve guides).

If the timing is out it could accentuate the above problems - you verified it is correctly timed - on each cylinder ?

opethiselps.

  

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RohanFri Jul-29-05 07:43 PM

  
#2. "RE: Dropping a cylinder"
In response to Reply # 1


  

          

Just a further thought on this. How new are your valves/guides, and what is your valve clearance like ? Its not impossible for a sticky valve to do this. If they or the guides are new then maybe one is too tight, either in the guide or with tappet clearances ? Or if the motor is well carboned up then maybe the same, although this is bit rarer these days, with modern oils, than it used to be...

  

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