T: Fuel Tank Amal 229/289 Carburation frustrations finally resolved

JohnA

Forum User
VOC Member
It may sound stupid as it is so obvious, but have you tried a hotter plug on that cylinder only?
My friends comet and my brother's comet had the same cr. same timing, same carb yet still needed different spark plugs.
Just an idea
Bernd
Thank you for your input Bernd, The rear cylinder is working perfect with the same plug and I feel reluctant to go down this route thinking it just hides the problem by hotter plugs burning up the oil. if all else fails....
 

erik

Well Known and Active Forum User
VOC Member
sometimes the resistor in the spark plug connector makes Problems.especially NGK ones.The resistance grows over the years.
 

JohnA

Forum User
VOC Member
It's not the plug as I have changed it every time I test. I will likely have to take the head off. :/ ty
 

erik

Well Known and Active Forum User
VOC Member
I don`t mean the plug ! i mean the connector or may be the high Tension cable has a fault making the spark weak when warm.
 

Texas John

Well Known and Active Forum User
Non-VOC Member
Those (NGK BP6EV and Champion N5C) are non-resistor plugs, so resistance really should not change over time. Resistor plugs do not play well with Magnetos, from what I understand. Those NGKs are supposed to be really great plugs, but perhaps someone has had a bad experience?
 

davidd

Well Known and Active Forum User
VOC Member
I have never had a bad NGK. I use B9's in the racer also. Others have reported problems. It may be the supply countries are different for the UK and the US.

David
 

Cyborg

Well Known and Active Forum User
VOC Member
Same here, NGK is the go to plug. There are lots of knockoffs, so if buying from EBay, I buy the NOS ones that come in Honda or Yamaha boxes. Probably safe to assume that the folks at Itsaknockoff don’t bother putting individual plugs in old dusty Honda branded boxes.

The NGK site has a link that shows how to identify some of the fakes, although they are always evolving.

Oil filters are also a big issue.

Ps. NGK factory in France. I always try and source Japanese manufacture although not sure if it really matters.
 

Mike 40M

Well Known and Active Forum User
VOC Member
I've heard that there is different ceramics in the France ones compared to those made in Japan.
Don't know if true, but I use Japanese NGK without problems on most bikes.
 
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