24 replies to this topic

[JanDyb]

Hi

Its me again. Just got the engine together for the 4`th time, and it is still burning gear oil. The third time i was able to drive about two hours before it began smoking but this time it was straight away.

I can not understand why it does this. Everything is looking 100% right. There is new bearings and new seals, and of course new middle gasket every time. I have had experienced mechanics both GasGas and other brand specialists confirming that it looks OK.

Lets say i pull it all apart again. Out with everything. Bearings, seals and all. Can someone please go through the mounting prosedure step by step for me, explaining what part and how You install it. Maybe there is something I have overlooked.

And Yes its (still) my 04 300 Pro.

Thanks!

-Jan

[copemech]

Thoughts that come to mind.

Perhaps you have a porous casting which is letting oil slip through?

Perhaps you could install the flouresing dye into the gearbox, run, then a blacklight inspection after teardown to see where it is coming from(if lucky).

Unusual, yet these things doo happen!

[JanDyb]

copemech, on Jun 29 2009, 05:53 AM, said:

Thoughts that come to mind.

Perhaps you have a porous casting which is letting oil slip through?

Perhaps you could install the flouresing dye into the gearbox, run, then a blacklight inspection after teardown to see where it is coming from(if lucky).

Unusual, yet these things doo happen!

Yes unlikely, but it could be true.. I dont know if I believe in it, but i`ll give it a try before next teardown anyway.

Must say that it is not only burning a little oil. After 10 min driving it hardly ignite, and there is a pool of oil coming out of my exhaust leak (wich does not have priority just now. Maybe later..)



-Jan

[totalshell]

are you absolutely sure that it is gear box oil?
if you run the engine with zero oil in the box what happens/ if it is the g/box oil how much is being burnt. castings 'may' be pourous but if the amount of oil is such that it accumaltes in the silencer very quickly then that cannot be 'just' a pourous casting. i'd have a look at a schematic for the engine/box and understand at what points oil could enter the engine and work from that

[totalshell]

i suppose the good news is that gasgas usa have some excellent video on youtube.

from the video the contact points between g/box and engine are clear and frankly relatively small.
if oil is entering the engine directly from the box it can only be via this joint. is the surface of the joint flat and level/ does it have the even the slightest of casting bubbles or imperfections?
when dry assembled with no gasket and a little enginners blue is the joint/ contact point complete?
are you using the gasket dry or are you using a 'smear' of sealant on both sides of the gasket.

if the joints are complete and your using new gaskets with a smaer of sealant when you take the old ones off is there any sign of gasket failure at the gasket?

if the answer is that oil is not enetring via this joint then it must be exiting the box via a bush /bearing and entering the engine via the mains bearing..a pretty unlikely though possible route

i would concentrate on the gearbox/ engine joint surfaces making sure they are both flat and level and then ensuring that the gasket and the slighteast smaer of sealant are 100% i would take care when bolting the crankcase halves together to tighten slowly and each bolt a half turn at a time and tighten the opposite bolts so that possible warping or twisting can be eliminated. any 'leak' will only be small so the slightest difference will make a difference..

good luck

[jorgep978]

my sherco done this and it was the crank case seal. the symptoms were a white cloud of smog being belching out from behind me. also i measure the new oil before putting it in then when i came back i drained it out and measured it again i noticed there was a lost less.
Try it.

[HAM2]

Test my memory time....2 of my mates had this Pro oil drinking problem( on the same 2005 bike??) though not as severe as you describe.
1st mate had the bike from new so the fault was with the factory assembly!
The cause was a washer 'missing' near one of the gearbox seals...it was only apparent when stripped alongside another Pro.
Sorry to be so vague, it was few years ago.

[JanDyb]

Thanks guys for helping me out.

1. Water? As I said it is "pouring" oil from the silencer joint so I am pretty sure it is gear oil. I have though changed top O-rings for new and tried to run it without any coolant (for a very short time of course) without any better result.

2. Gasket: I have been using new gasket every time (I have actually emptyed the stock at the norwegian importer) and always checked how it looks. The joint in the area where it could be possible to leak oil is very even and seemless. This is not the problem I think.

3. The washer you are talking about is it not a whole circle. (part nr 20 in the crankcase picture in the parts manual) There is a washer like this between the left bearing and seal. I was thinking the "hole in the circle" was there to allow oil to drain from the bearing back in the gearbox so I made sure the hole was pointing towards the drail hole in the casing. This could maybe be an issue?

4. The bushings that the seals are sealing against have an O-ring inside. I havent touched this becaus I didnt think it was possible to leak oil on the inside of the bushing. Could this possibly be the fault?

-Jan

[totalshell]

am i right then in that you think it is burning gearbox oil because oil is 'pouring' from an exhaust joint? if you have no other evidence than that then its not gearbox oil but premix!run the bike very lean for a tank of gas at about 50ml of oil for 5litres of fuel then run on 70ml of oil for 5 litre of fuel that could be the issue. but certainly do not strip it down if oil from the exhaust is the only evidence.
if you driane dthe gearbox oil (when warm) and refilled with recommended amount are you getting close to that when next you drain it?

Edited by totalshell, 29 June 2009 - 03:03 PM.

[JanDyb]

totalshell, on Jun 29 2009, 05:02 PM, said:

am i right then in that you think it is burning gearbox oil because oil is 'pouring' from an exhaust joint? if you have no other evidence than that then its not gearbox oil but premix!run the bike very lean for a tank of gas at about 50ml of oil for 5litres of fuel then run on 70ml of oil for 5 litre of fuel that could be the issue. but certainly do not strip it down if oil from the exhaust is the only evidence.
if you driane dthe gearbox oil (when warm) and refilled with recommended amount are you getting close to that when next you drain it?

Nonono... The bike is smoking like an old steamtrain. One round on the field makes it almost impossible to se past it.

I am taking the fact that lots of oil "pouring" (I am Norwegian - I dont always find the right words) from the exhaust and the fact that no coolant made any difference for evidence that it really is gear oil burning.

-Jan

[JanDyb]

Studying the parts manuals I found that the crank bearings have different parts number from 2004 to 2006. In 2004 the type is "6205 ETN9" part number M01216002/2 while in 2006 the type is "ST5225" part number MT280412006

What is the difference between the two? I see that in the 06 theres additional O-rings on the right side.

Could it be that I have got the wrong bearings or maybe if I use the 2006 bearings I have to use the O-rings also?

-Jan

[totalshell]

the bike certainly sounds to be burning a lot of oil. have you measured how much is left in the gearbox after running the bike. that will either rule the gearbox oil in or out as the culprit.

[JanDyb]

totalshell, on Jun 29 2009, 08:52 PM, said:

the bike certainly sounds to be burning a lot of oil. have you measured how much is left in the gearbox after running the bike. that will either rule the gearbox oil in or out as the culprit.

It wont run long enough (or I wont let it) to see any difference in oil level but I dont think there could be an other source. In fuel I run 1,5% Ipone (Goes like s h i t, smells like strawberry) and I can assure You that it dont smell any strawberry..

-Jan

Edited by JanDyb, 29 June 2009 - 07:00 PM.

[JanDyb]

JanDyb, on Jun 29 2009, 08:52 PM, said:

Studying the parts manuals I found that the crank bearings have different parts number from 2004 to 2006. In 2004 the type is "6205 ETN9" part number M01216002/2 while in 2006 the type is "ST5225" part number MT280412006

What is the difference between the two? I see that in the 06 theres additional O-rings on the right side.

Could it be that I have got the wrong bearings or maybe if I use the 2006 bearings I have to use the O-rings also?

-Jan

Dam*** I was hoping for a solution.. Studying more parts manual I think I can answer myself, but with a new questione...

The 06 has a complete different solution. First the bearings are sealed so there is no seals in addition. Then there is no need for the bushings either.

Question is: Can I remove the bushings, and use the 06 bearings on the 04?

-Jan

[totalshell]

if you empty the gearbox and let it run in neutral on the stand does it smoke pour oil out of the exhaust ( it will at first as the residue burns away) but it should run clear eventually.. no oil in gearbox no smoke //
always look for the easy answer before taking stuff to bits