1980 gs 750

[Smitty86]

So I've heard about this oil issue with the 1980 Suzuki gs750 something about the rod bearing not getting enough oil has anybody figured out a way around this or a solution to it just curious I'd like to get as much life out of my motor as I can before I rebuild it

[Rob S.]

Gang - is this one of the models that benefits from changing the oil pump gear?

[Nessism]

Info on this in the archives. Shimming the oil pressure relief valve is the fix. I'm not sure how effective the fix is, though.

[rphillips]

Changing the oil pump gears is gears from this GS750 to your GS1100.

[Smitty86]

Okay I've read about the shim thing you use a 6 mm spring to get 3 mm of shim is what it said on one of the threads I read on here cuz they said the 80 came with a high pressure oil system that's basically the same as the 1100 unless I read that wrong

[Nessism]

Okay I've read about the shim thing you use a 6 mm spring to get 3 mm of shim is what it said on one of the threads I read on here cuz they said the 80 came with a high pressure oil system that's basically the same as the 1100 unless I read that wrong

The 2nd generation 750, like yours, has a plain bearing crankshaft which requires high oil pressure. The early generation GS's, and the 1100's, have a roller bearing crank which is low pressure.

What you need to do is shim the oil pressure relief valve spring. Also use good oil like motorcycle oil or oil for diesel engines. No modern car oil, because that stuff is not ideal for old bikes.

[Smitty86]

Awesome thanks for the info this site and you guys have been a great deal of help as far as knowledge from experience