Stink oil transmission

[dyrberg123]

Hi guys,

So started tonight on my gt 200 project, barrels off, bores look good still on std bore, pistons off, looks great too but will fit new rings - crank felt ok too so did conrods with only 1,4mm side play..

But when draining the tranny the oil smelt quite a bit of petrol so i my mind it indicates oil seal faliure at the crank, what do you think?

Also some oil in the crank housing, but that doesn't smell as much as the transmission oil.

Thanks in advance

[Craig380]

Is it a GT200 X5 from the late 1970s / early 1980s? I had one when I was 18, GREAT bike

If it is an X5, the engine is really simple on those compared with the earlier Suzi twins, if I remember correctly it is only the right-side crank seal (behind the primary drive gear) which is exposed to transmission oil. I believe there is only one main bearing between the two cylinders and a single seal. Even the CCI system is much simpler, it's like the Yamaha system with just feeds to the inlets and no direct feed to the crankshaft.

My 10 cents is - don't worry about the crank seals, just rebuild the top end and go

[pearljam724]

These cranks can easily be flooded with fuel for a dozen reasons. Carb primed too long via the petcock, leaking petcock, improper choke useage, etc. Can happen to a perfectly mechanical bike due to human error. The oil also obsorbs a lot of unburnt gases, carbon, etc. Unlike a four stroke. They don't burn as clean and obmit a lot of carbon. The crank oil absorbs those emissions. Therefore these bikes crank oil always smell like carbon and gas. Just change the oil if it has a strong gas smell. To avoid ethanol swelling your crank seals. If it doesn't have a strong gas smell. Don't worry about it.

[dyrberg123]

Hi guys, thanks for your answers

yes it's an yellow x5, have been standing still the last 5 years with 20000 miles on the clocks..

But thats exactly the case, the 0,7liter tranmission oil smells much mor of gasoline then the small amount cought in the crank housing...

I am totally aware of the fact that the crank housing can have oil in it especially after a long period of still stand, but the oil in the transmission how can that smell of gasoline?

Cheers

[Vintageman]

but the oil in the transmission how can that smell of gasoline?

So, are you thinking that gas from the tank flooded the crankcase. Then gas sat in the crankcase and eventually rotted the rubber seals? I have seen that happen . Soaking seals in gas for a long long time is not good.. I suppose some gas could have seeped between the case halves and got into gear area as well.


How to tell if seal bad? The first easy step with jugs off is to fill the crankcase with your favorite liquid and see if it leaks past seals... and into gear area.

If you have engine out I would split case and give that area a good clean and reseal case halves. If seals decent shape, I would soak them in blue devil or ATP 205 to rejuvenate them if hard. If seal bad damaged then you know what you need to do.

[dyrberg123]

Hi vintageman,

Thanks for your answer..

What blue devil product are you referring too.?

[Vintageman]

Blue-Devil specific product I have used ->
http://www.bing.com/images/search?q=blu ... ajaxhist=0" onclick="window.open(this.href);return false;

ATP-205 I have used ->
http://www.bing.com/images/search?q=Atp ... ajaxhist=0" onclick="window.open(this.href);return false;

Both similar but think more reviews about ATP-205.... However, Blue Devil is on shelves in my area at Auto part stores so easy to get ($20.00 ).. ATP-205 I have to order off eBay for example.

[dyrberg123]

I will try.. thanks