Well, after much gnashing and heartache the IP11 is now back on top form once again. She had been coughing and spluttering, going down onto one rotor, most unhappy. I had convinced myself the carbs were to blame; I cleaned the dashpots several times, twiddled with the idle screw. I had even obtained a quote from AN for a carb overhaul, ultrasonic clean and reset of jet and float heights.
I then decided to change the plugs,C8Es, even though they were only 1,000 miles old. Instant transformation, not a cough or splutter anywhere !
I wonder if the Silkolene Classic 2T oil soaks into the porcelain and shorts out the spark ? she does run a bit rich oil wise. Perhaps if I ran a hotter C9E plug then the oil would burn off ??
She still ticks over, hot, at 2K rpm, despite several attempts to make air tight seals on the large and the small induction pipes. I've checked the Fast Idle Rod, and it is not holding the throttles open. I spend most of my time tearing round our wonderful Nth Yorks highways and byways, so this is not a major issue at the moment – still be nice to get it right though.
She eats sparkplugs !!
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Anthony Duffield
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- Joined: Sun Aug 11, 2013 8:13 am
Re: She eats sparkplugs !!
C7E is a hotter plug than C8E.
An uncontrollable tick over is usually air leaks, you say you have changed the O Rings on the induction tubes, what about where the carbs connect to the plenum chamber, air leaks anywhere along the air inlet route will give a high tick over.
What oil are you using in the carb dash pots, RN advises SAE 40 owing to the heat behind the covers.
An uncontrollable tick over is usually air leaks, you say you have changed the O Rings on the induction tubes, what about where the carbs connect to the plenum chamber, air leaks anywhere along the air inlet route will give a high tick over.
What oil are you using in the carb dash pots, RN advises SAE 40 owing to the heat behind the covers.
Re: She eats sparkplugs !!
Many thanks for your reply Anthony. I will check all around for air leaks, again !! I will also recheck the oil pump "C" setting before the the engine gets hot - the throttle angle when cold will be a better datum I guess.