Aprilia RS125 Burning Gearbox Oil

[3chris333]

Hello to everyone, I need some help/advice about my RS125 (Year 2000).

I have owned the bike for a year, last week it just died and wouldn't restart. When I removed the plug it was covered in thick black oil, a new plug let the bike run again but now it won't rev over 7k, throws out plooms of thick white smoke and has lost half of its gearbox oil.

It has no visible leaks so I suspect its burning it. Could this mean new crankshaft oil seals?

Would this be the reason it won't pull over 7K?

[MaybeGuy]

crank seals
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Blue_SV650S wrote: it was a sh1te wheelie, but it proves that he can get it up in 3rd and can do angles. In summery, mattsprattuk is a gobby little sh1tebag, dopehead tw4t, but sadly for all of us, he probably isn't THAT full of sh1te!!
Kickstart wrote: Hi I tend to agree with Matt. All the best Keith

[3chris333]

Would that account for not going above 7k?

[MaybeGuy]

probably, because its over oiling the bike
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Blue_SV650S wrote: it was a sh1te wheelie, but it proves that he can get it up in 3rd and can do angles. In summery, mattsprattuk is a gobby little sh1tebag, dopehead tw4t, but sadly for all of us, he probably isn't THAT full of sh1te!!
Kickstart wrote: Hi I tend to agree with Matt. All the best Keith

[3chris333]

I take it'll be the L/H crank shaft oil seal thats gone as I understand the R/H one is just to the flywheel where as the L/H one is where the transmission side is. Do you know if this seal can be changed with engine in frame? Didn't want to remove engine if I could help it.

[binge]

I have the same problem with my TZR125 engine. The Gearbox Crank seal has gone, It's sucking in oil and fouling up the plug, Causing it to run boggy.

On the TZR125 engine its a case of draining the gearbox oil, Taking off the primary gear, Screwing a screw into the seal and pulling it off the crank.
Then tapping a new seal into place using the oil seal and a hammer.


As long as the RS125 crank seals are external then it should be a similar scenario.




Ben

[Nathanmx]

Got to be your crank seals. There cheap buy but you might have problems fitting them if you dont know what your doing.

[bladerunner]

Yup left hand crank seal is very likely the case! It's possible to do it without removing the engine as said before. on the RS engine it's handy if you have a pair of circlip pliers to hand as the gears are held on that way rather than with nuts ala most jap stuff. As a point of interest when you take off the balancer shaft gears (the big plastic ones) you'll see there is a line on the end of the crank,both gears and the balancer shaft itself. These are all supposed to line up when facing each other. However I rebuilt one last month and it had bad vibration due to the marks being wrong. I took the gears off,thus the balancer shaft would drop to the bottom and put a pencil down the plug hole and turned the motor to TDC and put the gears back on.......the bleedin marks were 3 or 4 teeth out!!!! so check the marks on your motor before you remove the gears.

Also if your bike seems to be getting better it's not..it's just the gearbox oil has dropped and your now going to be sucking in air through the seal and running a dry gearbox!!!!!!!!!!

A last point of note is the genuine rotax seal has a hard fiber insert on one of the sealing faces and the after market seals do not........having had an aftermarket seal fail in 1000 miles I'll be doing the same fitting job as yourself but with a genuine seal this time!!!


HTH
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Current bikes...cbr929, KDX200's, Rd125lc mk2, RGV250's

[3chris333]

Thanks to eveyone for the advice, a job for next week I think.