Hi I am looking for a bit technical advice.  I have been finding when riding between sections and putting the engine under load that it is smoking a fair bit and stinks of burning oil rather than 2t.  I am assuming that my oil side crank seal has failed.  Does anybody know if I can replace the seal without a full strip down?  i.e pull the sealout with a self tapper screw or something?  Gasgas uk say I cant but i'm sure I have seen it done on one of the models.  If I can replace it without a full strip down would most people just replace the failed seal or do the flywheel side as well.

 

Thanks in advance for any help.

Gra.

The seal is facing the crank so the only way to replace it is to split the cases. There is no seal on the oil side since that is where it gets lubed.

I would get this one so you don't have to replace it again.

https://www.splatshop.co.uk/gasgas-main-bearing-with-seal.html

Thanks for the reply.  Looks like a full strip and refurb then.  Should be able to live with it until I have a window between trials.  Any advice on what else I should change when I'm in there?  Also I assume when removing the mains from the case you warm the cases with a heat gun and then press them out?

 

Thanks.

Are you losing oil from the transmission?  

2T oil build up in the exhaust will catch fire when the exhaust really heats up running under load.  It also smells different from normal exhaust smell, sort of like a barbecue.  If you just ride sections and then one day go off on a long hill climb, lots of smoke is expected.  

 

Thanks for the help.  Might try cleaning the front pipe out with some caustic soda and see how that goes.  Fingers crossed that it helps, certainly better than a full strip down!

If your transmission oil level is not dropping then your main bearing seal is good on the trans side.

The mid muffler is packed with a coarse stainless steel wool. When it gets red hot the oil burns off. If you are riding sections with little smoke, then go full speed in 6th on the road or go up a long hillclimb and it smokes like crazy, then you are burning built up premix oil. I would consider this normal and not do anything. Cleaning out the header won't help because it only has built up carbon that doesn't smoke much.

Thanks to all for the replies. Perhaps I got a little ahead of myself because of the smoke and the fact it smelled different. I will keep an eye on the gearbox oil level and see how it goes. 

 

Cheers. Gra. 

I concur; do the cheap/easy fixes first, such as repacking the muffler and removing the possibly oil-soaked packing.

Thanks. I'm all for the conservative approach myself. Any recommendations for exhaust packing? Are the sheets on Ebay up to the job?

For my older 2008 GGs - with the straight cylinder mufflers - I've have very good success with FMF 4-stroke packing as it is somewhat rigid and I find it holds its shape better when rolled. If your newer bike has the bent/curved muffler, that may not work for you, and you may need to get some of the conventional "loose" packing.

The Trials sub-forum on the Adventure Riders site had a recent discussion on how to best pack the mufflers of newer bikes.

Cheers will have a look. ?

I had the same symptoms and had only just changed the packing. Smoke smells different and engine runs erratically. Mine is the seal on clutch side and could be both. I'd say if it smokes but runs ok it'll be oil in the exhaust.

Yeah runs fine and checked the plug today and the colour looks good with no fouling so going to repack and see how it goes.   Cheers. 

Bit of an update. Did a trial yesterday with no noticeable smoke. It had shorter rides between sections so less load/heat from the engine. So all looks good. Will repack the exhaust this week then see how we go.