Topic: 1979 CB650 spark plugs

[Scotiabiker79]

So it’s shrove Tuesday.     In my resto project I had the bike running before after carbs rebuilt and oil change and putting the airbox on.  Then it started running horrible when starting
My confession lol.  I finally pulled plugs.  Black carbon.  I bought hotter plugs this afternoon started it and it runs like a gem.

  I forgot the cardinal rule.   Fuel air and spark. 

[Stev-o]

  I finally pulled plugs.  Black carbon. 

Good to hear ya got it running good. But, black plugs typically indicates a rich running condition, possibly too big [or incorrect] jets.  If you put in a hotter [non stock spec] plug, you may just be compensating for another issue. I'd keep an eye on it.  Good Luck

[Scotiabiker79]

Ok cool thanks for the tip.   I put rebuilt the carbs with carb kits from 4 into 1.  I’ll keep an eye on it.  Gonna get the carbs synched in a few weeks at a bike shop. 

[Stev-o]

   I put rebuilt the carbs with carb kits from 4 into 1. 

Are the carb kits aftermarket? If yes, that could be the issue.  Highly suggest only using Keihin jets, dont bother asking how I know this! Good luck.

[Scotiabiker79]

Lol.  Trial and error.  I’m not sure the brand of kits.  I assume it was aftermarket. The new plugs I put in r a 7 which is what the clymer manual says to use for Canadian bikes.  I pulled a plug out and it’s clean as new.  I had 8’s in the motor before.