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gt380 crankcase oil.

Posted: Tue Apr 12, 2016 9:11 pm
by dans6887
I know this is probably a topic already, but, I need to know what type of oil did I drain from my gt380. I drained the oil from the by removing the bolt in the underside of the engine. I have the clymer manual but I am unable to determine what type of oil was drained from this bolt. Also is this thge same oil in the crankcase? And finally is the black plug on the right side of the engine where I pour in the new oil ?

Re: gt380 crankcase oil.

Posted: Wed Apr 13, 2016 1:20 am
by Craig380
Hi and welcome. The oil you drained lubricates the gearbox and clutch, and is standard 4-stroke motorcycle oil. Some people use ordinary 10W40 4-stroke bike oil; others prefer to use 'light gear oil' for motorbikes. Both work, the choice is yours.

Just make sure whatever oil you use that it is motorcycle-specific and meets the JASO MA standard for motorbike wet clutches (it should list this on the label). The black plug covers the filler, just unscrew and pour in 1.5 liters. Check that you reinstalled the drain bolt first. Don't ask why I mention this :) The manual says change every 1500 miles, that's WAY too often. Every 4 - 5,000 miles is fine.

The crank, main bearings and cylinders are fed by the 2-stroke oil tank and pump. Any known brand of motorcycle 2-stroke oil will be a great improvement on the stuff available in the 70s.

Re: gt380 crankcase oil.

Posted: Wed Apr 13, 2016 11:21 am
by dans6887
Craig380 - thanks for the help. :D
Now I know what to tell my mechanic friend :up: