The New And Improved Unofficial R65 Forum V2

Technical Discussion => BMW Technical Q&A, Primarily R65 => Topic started by: Lucky_Lou on July 18, 2010, 02:50:43 PM

Title: Exhaust glowing red
Post by: Lucky_Lou on July 18, 2010, 02:50:43 PM
Got a phone call from my brother today he asked me to pose this question ,he is having serious problems with over revving and the right exhaust was glowing its a81 with electronic ignition. The carbs have just been ultrasonically cleaned and re jetted hes checked valve clearance and timing.
I think it may be time to replace the connecting rubbers to the head as it sounds like an air leak on the right  pot to me but i throw it out for your collective thoughts.
Lou
Title: Re: Exhaust glowing red
Post by: Bob_Roller on July 18, 2010, 03:14:08 PM
Sounds like a lean mixture, with the carbs being worked on, were the jets, needles and the like replaced ?

Possibly incorrect parts ?

Has the slide needle been replaced, as in wrong position ?
Title: Re: Exhaust glowing red
Post by: Lucky_Lou on July 18, 2010, 04:05:57 PM
Quote
Sounds like a lean mixture, with the carbs being worked on, were the jets, needles and the like replaced ?

Possibly incorrect parts ?

Has the slide needle been replaced, as in wrong position ?

Full kit on the carbs including Bing diaphragms as far as im aware the needle jets were refitted in the same setting they came off though that doesnt mean their correct.
Lou
Title: Re: Exhaust glowing red
Post by: steven m on July 18, 2010, 04:42:58 PM
If only one header is glowing red, actually glowing red, that sounds like an obstruction in the exhaust system causing a lot of back pressure.  Ever see photos of turbo engines on dynos, with glowing headers?  Lean is one thing, glowing red hot is another...

Just my two cents.

Steve  
Title: Re: Exhaust glowing red
Post by: montmil on July 18, 2010, 05:01:01 PM
Lou,  Is this over rev condition while at idle throttle position?

With the 'metered leaks' rebuilt, it may be that the idle mixture screw/s is/are turned way out and contributing to the warm red glow. Bottoming them out gently and open both no more than 1/2 turn and see what occurs.

Carburetor cables have a bit of slack or is the right-side still tugging on the butterfly shaft?

Is this right-side redness happening while riding?