Suzuki 2 Strokes

Is there a specific engine number after which we know for sure the factory changed the cases to allow for 1400 cc of gearbox oil? I've read stores about post-'73 and pre-'74 and some cases marked for 1200 cc but actually requiring 1400 cc... Is there a way to tell for sure w/o actually splitting the cases?

TIA

Anyone?

I think the short answer is 'sort of' - the change was made at the start of the 1974 model year, and per the service bulletin any engine after December of 1973 should have the modification so per this link, that should be around engine 68083. Plus there are several engine number lists around - another list shows 1974 engines starting at around 70224 - I suppose if yours is higher than 72000 then it should be OK, but don't quote me.

My 1977 GT500 does have the casting changed to show 1400cc, but I don't know when they started doing that - also I've been told that as the indicator hole on the side cover was supposedly never changed if you don't carefully measure, but instead rely on the oil weep hole to tell you how full it is, then you will still under-fill by about 200 cc's.

Does that help ?

Thanks Ian - clear as mud I guess! I'll probably split the cases this winter at some point and will find out for sure. The engine in my '73 has never been apart so I guess it's time.

have a look at this Frank.
all T500 need 1400cc oil in after this mod.. anyway see for yourself Frank.
http://www.ozebook.com/compendium/t500_files/oilmod.htm

Thanks John - the oil level question has been in the back of my mind ever since I got this bike, probably 6-7 years ago. But I don't ride it all that much... I'm hoping to do some land speed racing next year and will have to check seals, etc. before that.