The New And Improved Unofficial R65 Forum V2

Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: manxr65 on August 31, 2010, 03:44:07 PM

Title: carb popping
Post by: manxr65 on August 31, 2010, 03:44:07 PM
can anyone tell why this is happening.

i been out all day and stopping at different places , turning the fuel off at every stop . as my r65 is a cafe racer i only use a toggle switch as an on/off instead of a key. the thing is when i return to the bike after all different times i flick the toggle switch to power up and one or the other carbs will blow a puff of smoke out as if its just sparked and burnt excess fuel , how would this happen and why and how do i stop it
Title: Re: carb popping
Post by: Bob_Roller on August 31, 2010, 04:41:41 PM
Don't know what year bike you have, but with the electronic ignition bikes, when you turn the key, or in your case a switch to the on position, the ignition system fires both spark plugs .

One of the little quirks of the bike .

If you have fuel in a cylinder an open intake valve, the fuel gets ignited and you get a small pop or wheezing/whistle sound from the engine .
Title: Re: carb popping
Post by: manxr65 on August 31, 2010, 05:12:15 PM
yes thats right , that blowing sound , an i have a boyer fitted . mines a 79, so it normal then. just a bmw thing
Title: Re: carb popping
Post by: montmil on August 31, 2010, 07:36:28 PM
Quote
...so it normal then. just a bmw thing

Yep. I will occasionally toggle the right-side cut-off switch just to enjoy the little "poof" from the EPCO muffs. If it doesn't ignite a small flash, I'm disappointed.

BTW, On my 1981 R65, I have a simple toggle switch instead of the keyed ignition.

Monte [smiley=bath.gif] Hey, look... bubbles. Poof!