Surging RPM Rotax 503dcdi

by Nick Axworthy in 2 Stroke Technical Questions 11 years ago

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Re: Surging RPM Rotax 503dcdi

by Nick Axworthy » 11 years ago

Nick Axworthy

16 325 0

Hi Bill all back to normal now,

Had a good look at the carbs again to make sure all looked ok...nothing noted....checked the throttle operation again no sticking or binding...checked the synch...just a tiny bit out but I did re-set that,

I did notice quite a lot of 2 stroke oil all around the internals of the carb...I would expect some but it seemed a lot,

I cleaned the air filter as it was contaminated with 2 stroke oil...and the oil I use is the same shade of red as K+N filter oil so not easy to see....I think it gets onto the air filter when I fold my trike to take the wing of...this tilts the engine to 45degs and I sometimes forget to drain the carbs before I fold it....fuel then spills onto the filters ect...anyway I had to clean it 3 time to get rid of all traces,

There is an aircraft tech I know who told me he never oils K+N filters that are used in A/C as they operate in a clean environment and prefers to leave them dry...this is what I have done...be interested in your views on this Bill,

Anyway after its test flight is now purring and a joy to fly with,

Thinks for your advice Bill.

Nick.

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Re: Surging RPM Rotax 503dcdi

by Roger Lee » 11 years ago

Roger Lee

125 5.12k 4.53k

Hi Nick,
You should oil K&N oil filters to make them operate as designed. There is pleany of dust and dirt in the air and on the ground. The issue isn't the oil it's applying too much oil. They only get a very light coat or spray. The oil will. Spread so when applying it should be so light that you can still see the white'ish background of the gauze. Applying too much oil cause it to obstruct the filters normal air flow and it sucks in all that extra oil into the carbs.

Light coat and you'll be good.

Roger Lee
LSRM-A & Rotax Instructor & Rotax IRC
Tucson, AZ Ryan Airfield (KRYN)
520-349-7056 Cell

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Re: Surging RPM Rotax 503dcdi

by bill martin » 11 years ago

bill martin

10 757 0

Nick,

Roger is right. a VERY LIGHT coating of oil should be applied. Too much oil will impede airflow through the filter media and the excess oil will find its way to the bottom of the filter.

If you are using the oil injector, it is not unusual to have oil in the filter after the plane has been in storage for a few days or longer. The banjo bolts on the injector have built in check valves which sometimes leak slowly when not in use. This isn't usually a problem other than smoking a bit when the engine is started. If one of the banjo fittings does get bad enough to lose a lot of oil in storage, they are relatively cheap (as Rotax prices go) and easy to replace.

Bill.

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Re: Surging RPM Rotax 503dcdi

by Nick Axworthy » 11 years ago

Nick Axworthy

16 325 0

Its pre mix Roger...I will give the filter a coating then...thanks guys.

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Surging RPM Rotax 503dcdi

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