Unofficial Royal Enfield Community Forum

Royal Enfield Motorcycles => Vintage Royal Enfield => Topic started by: mbpinto123 on January 23, 2013, 08:54:08 pm

Title: interceptor carb not sucking air
Post by: mbpinto123 on January 23, 2013, 08:54:08 pm

hi everyone, I have a 1969 series 2 750 that runs very good!  The problem I have noticed is that the left side carb does not have very much draw when you put your hand over the mouth.  The right side carb sucks your hand into it and will shut the engine down.
boyer ignition, timing is dead on
brand new amal carbs
recent valve job
bright blue spark
carbs are sync properly
compression is 155 on left 150 on right
bike starts first kick
left cylinder feels colder than right but eventually gets hot.
any ideas? 

Title: Re: interceptor carb not sucking air
Post by: Arizoni on January 23, 2013, 10:40:25 pm

Sounds to me like the carbs are not sync'd properly.
They should be both drawing in the same amount of air at all engine speeds.

Title: Re: interceptor carb not sucking air
Post by: ERC on January 23, 2013, 11:24:18 pm

Either your valves are NG or Arizoni is right on the money. Pull the plug wire off when running to see which one slows down or kills the motor.   ERC

Title: Re: interceptor carb not sucking air
Post by: barenekd on January 26, 2013, 06:42:58 pm

Sounds like the slides aren't synced. Put a finger down the carb throats and feel the slides as they start rising when opening the throttle. They should start rising together. If one starts before the other, the engine won't ever run right. Adjust the throttle cables to cure this.
Bare

Title: Re: interceptor carb not sucking air
Post by: gunnerasch on January 28, 2013, 04:02:49 am

Bad seal under the carby that isnt sucking as much.

Title: Re: interceptor carb not sucking air
Post by: mbpinto123 on January 31, 2013, 07:46:51 pm

Well I thought I had the carbs sync properly..I decide to double check and low and behold...  thanks for the suggestions....