hello again!

when I turned around after I had driven on 5/6th gear I saw much of blue smoke. in the past I often had to remove oil from gearbox and it always seemed there is less than I poured. so my question is: from which places can the engine take oil? I've actually bought oil seal 43 from the picture below, and I guess i have to buy center crankcase gasket (13) because it's single-use isn't it? which seals can be also broken?

regards

Does it smoke (a lot) all the time or just after a blast, may just be oil in the exhaust?

if it was the gasket it would suspect it would empty the gearbox rather quickly!

 

Edited October 21, 20178 yr by suzuki250

on idle for example it's okay, it doesn't smoke a lot.

so as I said, it takes the oil quickly in my opinion. but I've changed the gasket not so long ago because I had to change secondary shaft. have I done something wrong? what do you think? and are there different places from where it could take oil

A bunch of smoke out the back of a 2 stroke after a blast down the road in 5th and 6th is normal. I think you're looking for a problem where there is none. You're just burning up all the premix that had built up in the exhaust from all the idling that trials bikes do. 

but then what about losing the oil from gearbox?

Test it this way, from cold

1. Start your bike, let it idle for a bit and note how much it smokes, in Neutral rev it up as though you are about to hit a 4 ft splatter.  Does it smoke the same as idle or more.  If more you most likely have a seal of some type leaking.  If smoke is the same go to step 2.

2. Go for a blast in 5/6 gear getting exhaust good and hot. Does it smoke more now, if yes probably just oil build up in exhaust burning off.

You mention losing gearbox oil so I am betting step 1. will smoke more.

common Locations of oil getting into cylinder:

crank seal / associated O-rings on clutch side, center gasket, 

 

Depending on what year GasGas Pro you have you may have the new upgrade crank bearings or you may not.

If you have the old style like I do there is a collar on the crankshaft, this collar has an O-ring between the collar and the crankshaft.

I had that O-ring go bad once and the bike was consuming oil.

It is a right Bas*ard to change and I changed the O-rings and collar.  Old collar comes off hard.

Have you measured the oil in - out, or are you just estimating?

 

thank you all for quick responses

yes, I measured it, there was always big difference.

my gas gas is from 2008. so about these o-rings, you mean that part number 20 from the first picture can be also possible source of the problem? 

14 hours ago, gg25 said:

thank you all for quick responses

yes, I measured it, there was always big difference.

my gas gas is from 2008. so about these o-rings, you mean that part number 20 from the first picture can be also possible source of the problem? 

the O-ring part number 20 in your pic may be a source of issue, but that O-ring may be integrated into the new style bearings that eliminates the need for the collars that I have on my bike.  the O-rings and collar I was referring to are Part numbers 1 and 2 in this Pic:

 

It appears to me that according to your parts listing for 2008 you have the "new" style main bearing. (pic below) this has the O-rings number 20 sand 41 built in.  I am not sure if these O-rings can be purchased separately.

Pic of "new upgraded main bearing" Note the internal and external O-rings.

as I see I don't have these parts you mentioned. to sum up, I need parts 13, 20, 41, 43 and after changing all of them I can be 100% sure that's everything okay with oil from gearbox, right?

thank you so much again

regards

 

21 hours ago, gg25 said:

as I see I don't have these parts you mentioned. to sum up, I need parts 13, 20, 41, 43 and after changing all of them I can be 100% sure that's everything okay with oil from gearbox, right?

thank you so much again

regards

 

 

Well, I am not sure about 100% , but I would say that if those parts are changed you should be reasonably confident that the usual ways for gearbox oil to get to the combustion chamber are fixed.

Be sure to take note of the location of the outside hole of the main bearing when you pop it out to change 41, it needs to match up with a hole in the cases to allow the gearbox oil to lube the bearing.

 

Good luck sir, and may your oil troubles be fixed.