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TYler , Whatd kind of oil are was the engine been using prior to the seizures ?

Were they cold seizures ?

i was using Yamalube at a 40:1 mix.

this time, i'm using penzoil air cooled at 32:1 in the other JPXs i have running on my 2-seater. i figure the richer oil mix will keep them cooler and more lubricated, but i'll keep my eye on the plugs for fouling.

T.

Is the yamalube mineral or synthetic?

also the fuel acts for cooling as well on a 2 stroke and a overly lean condition will not cool as well.

Were the engien fulll warmed up ?

yep fully warmed up, and the last one was at 200'

mineral yamalube, i stay away from synthetics and 2-smokers. haven't heard any good arguments yet about their advantages. i have a feeling there's a dried out gasket on the engine somewhere and is sucking in air leaning out the mixture.

same carbs on the other two JPX's on my 2-seater and they are running strong.

T.

leaking crank seal will give you lean conditions.

you have a egt gauge now ?
If so that will be your first inidcator of pending troubles

PLugs actuallly tell the tale the best and EGT did give you a real time indication of changes in realtime.

Did the plugs indicate and differance from cylinder to cylinder and from engine to engine when it failed ?

had just finished changing the crank seals. both plugs were white. suspecting something wrong with those reed valves now, but thats a project for after i rebuild the fuselage with george-made series III gear.

T.

white plugs normally indicate lean --VERY LEAN .
what did piston look like ?

yes thats how i knew it was seizure and not fuel starvation. white plugs bad - chocolate brown plugs good.

haven't gotten to that yet, like i said, probably a project for the spring. i'm knee deep in grinding and cutting aluminum to make my skiis. have one almost done, starting the other tomorrow hopefully. i'll have to take a pic of the scenery for the lads down under who've never seen a white landscape.

Tyler

a few pics of my first flight on skiis ever