rd 500 gearbox oil pump

[tritonpat]

any ideas on the gearbox oil pump, is it really necessary to to run one as im sure there is plenty of oil sloshing about in there, has anyone not fitted one ? any thoughts on this subject

[silverstrom]

Why would you even consider that?

[tacky1]

Yamaha put it in there for no reason at all!!!!!!!!!! It pumps oil through the upper half of the gearbox that doesn't get oil spalshed...

[tritonpat]

its just a thought as i am building a engine using 350 ypvs barrels and heads but standard stroke, i am not going to run the balancer shaft as its going to have a 90 degree firing order (ie screamer) , or the 2 stroke pump as its going to be run on premix, also the quieting gears will be left out. my thinking was is it really necessary, havent come across other bikes with a gearbox oil pump

[tacky1]

That sounds like a great build!!! Please post a few pics of progress, The pump is for the top half of the engine as the cases are tall and there is no splash for the top clutch shaft.

[silverstrom]

havent come across other bikes with a gearbox oil pump

TZR250/TDR250 have a gearbox oil pump.

[tritonpat]

ok, thanks for your help, i think i will leave it in there just to be safe

[phildu31]

Your rear crankshaft will thank you ...

[jackson.40]

Some info from Stan about the gearbox pump............

[tritonpat]

now thats interesting, i think i will give this more thought, to be honest i was thinking along the same lines, ie does it do anything, maybe better without it thanks for the info

[lost1750GTV]

That carb set up is simple brilliance.

[tritonpat]

cant agree about the carbs will cause a lot of problems, i am sure it wont run nice in traffic or slow speeds ie cruising, would run better with 4 carbs

[wolfgangh]

Stan forgot something important I think: the gearbox oil pump does not only feed the twostroke oil pump and the friction gear; there is a second line that goes into both gearbox shafts and feeds oil into the gearbox from above. Something I would not remove.

[Speed Freak]

The gearbox is planned to get pressurized oil.
Gearboxes with splash oil lubrication are designed in a different way like roller bearings on the gearwheels which can rotate on the shaft or at least there are design features which lead oil into the bearings.
This bearings are not really loaded when they spin as the gear is disengaged then but I have found a failed bearing in a GSXR 750.

And the reliability of gearboxes with splash oil lubrication... Just read a bit how good the RG500 gearbox works.