Earl

[Guest]

Just curious if the Rottela T 15w40 oil is still a good choice for a 78 GS 750?

I remember somebody in the car world telling me a couple years ago that they changed their formula, but dont know if there is any truth to it.

[Gold01ca]

Run Rotella T with confidence,
quite popular around here.

[Nessism]

The newer formula has less zinc and phosphorus, but it's still pretty good.

[bwringer]

It's still JASO MA rated, so it's officially safe for wet clutches.

Great stuff for motorcycle engines, and inexpensive. The only reason I will set foot in Walmart is to stock up on oil. For some reason, it's significantly cheaper at Wally World than anywhere else.

[born2lose]

Alright I suppose the Rotten T is still the oil of choice, I am down

[TeamNeal]

Is Rotella T suitable for an 81 16 valve 750?

[Nessism]

Is Rotella T suitable for an 81 16 valve 750?

That particular GS engine is the only one that's truly problematic: spun crank/rod bearings and damaged camshafts/rockers are disturbingly common. If I had one of those bikes I'd shim the oil pressure relief spring to increase oil pressure and use some high zinc oil. Rotella is decent, but I'd mix it with some Valvoline Racing or Brad Penn for the higher ZDDP (zinc and phosphorus).

[Steve]

That particular GS engine is the only one that's truly problematic: ...

Was it just that one year or the range from '80 and up? Maybe through '83 or so?

Just the 750? How about the 700?

.

[salty_monk]

81-82 - 16v 750 seem to be the ones. 83 16v is substantially different and the 1100 doesn't seem to suffer same problems.

[TeamNeal]

so i guess im riding a potential disaster, and should be expecting an extensive rebuild soon.......

[koolaid_kid]

so i guess im riding a potential disaster, and should be expecting an extensive rebuild soon.......

Shim the oil pressure relief spring and use a high zinc oil as Ed (Nessism) suggested.