HELP

Hi all have hit a snag with the oilseal. I need a puller to remove the flywheel under the big nut on the clutch side. Anyone know whats it's called and where one can get hold of one. It looks like it would have two bolts that go into the flywheel with a bar that would go over the main shaft and then another bolt that would screw down on the main shaft.  Have put up a picture of the part that has to come off.

Thanks for that oni nou, Have ordered a 13 piece universal puller. Should do the trick. I an getting quite a selection of pullers now.

Edited October 12, 20178 yr by nubsey

Just thought that I would let you all know the final outcome. Got a puller and the flywheel came off as easy as pie.

This is what I saw underneath.

 

 

It looks as if the seal is in the wrong way round, also the is a nice hole in the seal. Replaced it with a new seal, and had the metel ring on the outside facing the fluid. Now there is a huge improvement in the smoke, it still smokes when revved hard, but nowhere as much. Also we are running on 50/1 premixed fuel. Thanks for all your help.

 Nubsey

 

Never seen one  with a hole in like that, but it looks like its installed correctly (hard to tell from a picture)

Edited October 12, 20178 yr by suzuki250

Oh Dear, I was always told that the spring side went towards the oil. I.E. the oil is in the clutch case so the spring goes that side. So now I have an oilseal round the wrong way. Double oppps. This of course is where you need a workshop manual. Also, you wonder who puts a bike back together with a hole in the seal.

 We live but sometimes we never learn

7 hours ago, nubsey said:

Oh Dear, I was always told that the spring side went towards the oil. I.E. the oil is in the clutch case so the spring goes that side. So now I have an oilseal round the wrong way. Double oppps. This of course is where you need a workshop manual. Also, you wonder who puts a bike back together with a hole in the seal.

 We live but sometimes we never learn

Hole was probably an attempt to lubricate the main bearing, might find it still has a seal nearest the con rod.

4 minutes ago, oni nou said:

No other seals in there just the open main bearing and that seal.....the fact it has the hole in it means it sucks a small amount of air through the hole on the piston upstroke into the crank case and expels a small amount of air/fuel mix from the crankcase on the down stroke through the open bearing and then through that hole

Accept thats the way it "should" be, won't know till he checks it ....  Might have mains with one seal.

Edited October 13, 20178 yr by b40rt

14 hours ago, nubsey said:

Oh Dear, I was always told that the spring side went towards the oil. I.E. the oil is in the clutch case so the spring goes that side. So now I have an oilseal round the wrong way. Double oppps. This of course is where you need a workshop manual. Also, you wonder who puts a bike back together with a hole in the seal.

 We live but sometimes we never learn

Don’t worry about it too much, it probably won’t last long but just use the bike until it starts smoking again

At least you will know whats wrong when it does

Edited October 13, 20178 yr by suzuki250

 

On 10/7/2017 at 11:18 AM, nubsey said:

 

HELP

Hi all have hit a snag with the oilseal. I need a puller to remove the flywheel under the big nut on the clutch side. Anyone know whats it's called and where one can get hold of one. It looks like it would have two bolts that go into the flywheel with a bar that would go over the main shaft and then another bolt that would screw down on the main shaft.  Have put up a picture of the part that has to come off.

 

Personal opinion here. Possible "keyboard warrior" moment.  without actually being there to see the bike etc.

I think some of my very knowledgeable fellow TC home mechanics may be getting confused due to terminology being used.

The pic above Nubsey has referred to as the "flywheel behind the big nut".  Most of us when we see "flywheel" we think of the stator side of the engine and a hole in that seal would suck in air, causing a lean condition making the bike rev higher, etc... But what he is actually referring to here is the gear on the crankshaft that drives the clutch basket.

So my recap:  (if I am incorrect please let me know)

Bike is a 2000 GasGas, this is before the pro and the motor is very similar to a Sherco of the same year.  (because Sherco based theirs on GasGas).  There is only one Crankshaft seal on each side of the motor.

The hole in the Crankshaft seal on the clutch side of the motor behind the crankshaft gear pictured above will allow the gearbox oil to be sucked into the cylinder and burned, causing massive smoking and the loss of gearbox oil.

I believe the spring side of the seal is to be oriented towards the "pressure" side of the seal, in this case, as the piston comes down it will provide pressure toward the seals and this will actually "push" the seal against the shaft assisting with the sealing abilities.

I think the remaining smoking when revved hard is due to running 50:1 on your pre-mix.  Yes it can be done, yes it will run, but it is not necessary to run that much oil in the premix.  Most trials bikes are running 80:1, a few at 70:1, a couple at 90:1, I even heard of one running 100:1.

If you have not repacked the muffler there could be some smoking from there if it happens after running it hard down a trail getting the exhaust very hot and "burning" the oil out of the muffler packing.

 

OK sorry for long post, "keyboard warrior" moment has passed.

(don't know why the hole was in the seal, may never know, chalk it up to gremlins)

On 13/10/2017 at 3:42 PM, oni nou said:

Yes sorry about that.....don't know what I was thinking I was coming at it from the wrong angle.... I once listen to someone saying that they had oiled the disc on their bike because the brakes were squeeking .....its hard to argue with the logic of that. It probably fits with the same idea that if the main bearings are pitted and rumbling then they are obviously dry and in need of a bit of lubricant...the lubricant has got to go in somewhere....its hard to argue with the logic of that.

Not sure if your taking the urine ? Bantams lubricate the main bearing with gear oil in the way I described. 

19 hours ago, oni nou said:

A perfect assessment of the situation as regards what I said on the subject; down to a tee  and on the oil thing  the Vertigo motor in the UK  and other places in Europe runs on a mix of 200:1 and there have been no complaints over a years usage ..... there is also a post on here of some one in Italy in a region where it gets a lot hotter than the UK  and he has been running 80:1 in an aircooled twinshock trial bike for along while and after the first year of running at 80:1  he says that he stripped his engine and found no abnormal wear.

This key board Warror thing is getting like Trumps "Fake News" media captioning........mind you it is very on trend ;is it not, given the current sabre rattling going on around the planet ,performed on Twithead and facefxxx

I only mentioned "keyboard warrior" because I wasn't sure if I was explaining what people already knew and I may have mis-interpreted their posts..  But from the sounds of it we are all on the same page of what the issues are with Nubsey's bike. and what the repairs should be.

Oh this is getting needlessly messy...    I am going back to my coffee.

I would rather not discuss Trump, "Fake News", or the Sabre rattling that is occurring on social media, too much drama and anger there. 

Nubsey,

Keep us informed on the performance of the bike, and hope you have many hours of fun with the grandson.

Hi all and thanks for the many posts.

 All understood. As I said I wrongly assumed that the spring went on the oil side, so it is in the wrong way round. Still it seems to be working ok at the moment, so thats the way it will stay. I will have to ruin the seal to replace it, so might as well leave it there till it goes again. Have just returned from a long weekend away. It was not meant to be a long weekend, but the alternator packed up on the car, so was unable to return till it was replaced.Years ago I would have thought nothing of replacing it myself, but nowadays you are lucky to be able to see it, let alone replace it.

Will have ago at repacking the exhaust sometime soon. If we can get it lawnmower quite then he can do some practice in the back garden 

 So far the bike starts up much better than it did, and the smoke is unseen on low revs, Finding neutral is quite hard as you cannot rest your foot on the footrest, and just lever it upwards for neutral. Loads for the lad to learn. Once again many thanks for all your help on the subject.

 

 Nubsey

Don't worry about finding neutral, its never been easy on a GG most riders use there hand! 

suzuki250 you are a genius.  I told the Grandson that I done it by hand because of my age, and I was not so flexible. So now I can tell him to do it that way because, Granddad told him too. It really is a pig to do it with your foot.