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Gas Gas Gearbox Oil Gone Black After 10Mins?

Featured Replies

Hi Guys,

 

My gas gas Tx 270 was not starting so I decided to take a look! I kicked it over about 10 times and no go! so I removed the spark plug to find it soping wet! too wet for my liking, so i contuined to kick it over and just as i suspected petrol mist flying out from the head into the air, so it had hydrolocked! which is not common thing with these old bikes! the plug wasnt sparking eather, so off with exhaust manifold to empty out all the petrol, but only half a coffee cup came out! yes i was expecting more! anyway kicked her over to clear her up and then drained the gearbox oil, only to find a black/gray color of oil! so i checked water level and it was fine, put eveyhing back and put new plug on it and dex3 in the gearbox and tryed starting it, 3 kicks and she was runnng, and running sweet! so i left it in gear ticking over for 10mins and droped the oil again as i could see it had gone black/gray! well 3 times the amount came out again with that crappy color! so now i thinking i need the expertise of you guys?

So if you guys have any ideas?

I would be greatful

 

 

 

My thoughts are, Crankcase seal damaged when hydrolocked and kicked over!

 

 

Cheers all!

 

post-19212-0-89863000-1453667399_thumb.jpg

frist oil drop

 

 

post-19212-0-32799000-1453667451_thumb.jpg

Second oil drop

 

 

 

 

 

 

If you bike had "hydrolocked" you would not have been able to kick it over. If the excess fuel in the crankcase had damaged the seal it would almost certainly not idle steadily.

The grey much in your gearbox has probably been there a long time, its a mix of fine metal particles and clutch lining. The stuff that gives the cloud effect in the oil is aluminium dust from the clutch plates. It will have settled out and sort of turned into a gum. Each time you put new oil in it the additives in the new oil dissolve some of it and the oil turns dark. Your gearbox will need several flushings with either flushing oil of high detergent diesel engine oil to clean it out.

Spend money on a few oil changes, if it continues looks like water contamination. Do the oil checks first

that would be water in your oil. you sometimes need to run a few changes through the bike before it clears up. if it still happens your losing coolent.

--Biff

  • Author

Ok thanks for your reply guys! it great to have all your help!

 

the oil i put in was the pink dex3? would water turn it black or would it turn milky if coolent was leaking in?

 

the bike is running fine otherwise, no clutch drag at all, and whats the best way of flushing out the gearbox? just normal diesel engine oil? do i run the bike with that stuff in the gearbox too? or should i stick to just using dex3, the dex3 here is 10euro per leter tho!

  • Author

If you bike had "hydrolocked" you would not have been able to kick it over. If the excess fuel in the crankcase had damaged the seal it would almost certainly not idle steadily.

The grey much in your gearbox has probably been there a long time, its a mix of fine metal particles and clutch lining. The stuff that gives the cloud effect in the oil is aluminium dust from the clutch plates. It will have settled out and sort of turned into a gum. Each time you put new oil in it the additives in the new oil dissolve some of it and the oil turns dark. Your gearbox will need several flushings with either flushing oil of high detergent diesel engine oil to clean it out.

 

Now that you mention it, when i took off the sump plug i was thinking i was gona see lot of metal particals stuck to the magnet on the end of the plug, but no! a very thick sludge was on the end of the plug!

still its puzzling how 3 times the amount of oild came back out again!

I would also check waterpump or play. Those seals and shaft wear and coolant gets into the oil making it lose the normal collor.

 

 

 

/I was thinking about a pro

Edited by crazybond700

ATF goes bright pink when mixed with water.

 

I used to flush the old Sherco boxes out with petrol every so often, never done any harm on mine.

I've flushed boxes with petrol too,surprising what comes out.Dont start it though

  • Author

Nice one guys! great info there to go and try,.......... I put normal diesel engine oil in the gear box today and ran it up for a while,  ha my bad was even clutching it in and out of gear no problem, the gearbox got hot quick tho!, anyway I emptyed out the gray crap again then put new pink dex3 in, think I will just run it for awhile and see what happens!

and just for the recored I thought of putting in pertol in the gearbox to flush it out but I chickend out as i thought it might disintegrate the clutch! oh well i will know for the next time!

Hi you have water getting into you oil had same problem on my sherco its the gaskit seals at the water pump   you need new ones

Edited by dwb5151

  • Author

yeah i had a 02 pro that loved gearbox milk shakes! so yeah water in gearbox turns milky, but the black/gray had me puzzled!

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