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TECHNICAL MOTOBRICK WRENCHING In Remembrance of Inge K. => The Motobrick Workshop => Topic started by: keith g on January 27, 2015, 12:02:16 PM

Title: K75........misfiring and no idle
Post by: keith g on January 27, 2015, 12:02:16 PM

it started to misfire just before christmas put new plugs and wires on her but the problem is still there........i'm open to suggestions as to what may be the cause.....!!

Title: Re: K75........misfiring and no idle
Post by: TimTyler on January 27, 2015, 12:09:30 PM

My money is on "air leak".

Title: Re: K75........misfiring and no idle
Post by: keith g on January 28, 2015, 05:23:25 AM

i was hoping it would be simpler than that....:)
but it is an '87 model and all original.......the inlet rubbers are def past there best......oh well......in the garage...pull her to bits...:(

Title: Re: K75........misfiring and no idle
Post by: Inge K. on January 28, 2015, 05:37:40 AM

Start With checking the crank ventilation hose......S shaped, at the rear end of the plenum chamber.
They have a rather short average lifetime.............

Title: Re: K75........misfiring and no idle
Post by: TimTyler on January 28, 2015, 11:41:21 AM

What Inge said.

Air leaks aren't necessarily expensive or hard to fix, and they can be easy to find with a spritz of carb cleaner.

You could also try replacing your fuel filter which might be clogged and you could check to see if there's a bunch of mice living in the airbox.

Title: Re: K75........misfiring and no idle
Post by: keith g on March 15, 2015, 05:10:29 PM

Tim.......you were right.......airleak.......when i took the throttle bodies off,the centre inlet stub came with it...!!!,all new rubbers fitted,runs better than ever...!