Oil leak 3AJ

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JohnXT5T
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What Bike or Bikes Do You Own?: Tenere 3AJ 1988. Tenere 700 Rallye 2022. Triumph Speed Twin 1957.
Previously Owned Bikes: BSA B40 trials, Montesa Cota 123. Honda C70. Kawasaki KH250
Location: Kent, UK & Burgundy, France

Oil leak 3AJ

Post by JohnXT5T »

Well I opted to top up the oil rather than do a complete change yet. But, I have a serious oil leak.. almost all leaks out and I don't know where from. Looks like its coming from higher up the engine, maybe facing the oil tank somewhere. Difficult to see in there with the tank in place.
Is the tank easy to remove? Any obvious pipes or connections I should check without tank removal first?

Thanks guys
donnybach
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Re: Oil leak 3AJ

Post by donnybach »

Crank case breather easiest to check without removing anything. Spews it out under pressure if it slipped off. After that, clean everything, tank off and look for leaks while running from a fuel supply. Probably something simple.
motorang
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Re: Oil leak 3AJ

Post by motorang »

It is worth noting that with any dry sump system there is a chance of the oil running down to the engine (which it only should do over a longer period of time), leaving the external oil tank with a seemingly too low oil level.

Once the engine is running, the excess oil will be pumped up to the oil tank again. This will take a few minutes and medium rpm to establish a "true" oil level, which is why you do a few things differently from other engines.

1) If the bike is new to you and you are not sure if the oil level is OK you drop all the oil (engine and tank) and refill the amount as per specification.

2) Now you know there is roughly enough oil in the engine, you always check AFTER a ride, right after switching the engine off, without letting it idle on the side stand. This is when the true oil level can be assessed.

Letting the bike sit a few minutes or idle a few minutes may change the oil level.

So what happened is most likely there was enough oil there, just not easily to be measured. So you topped up a litre, and that excess oil is now getting foamed up by alternator and crankshaft and bubbles up through the crankcase breather into the air filter, from where there is a little hose valve to let the oil drip out. Most of it will be soaked up by the foam air filter, causing the engine to stutter and run rich with some smoke from the exhaust.

I again would recommend to make a proper oil change. Drain the oil from engine and oil tank, then refill as per spec.

Remove the air filter and squeeze it dry (you can wrap it in paper towels to do so). The filter foam should only be moist, not dripping when squeezed.
If you are anxious to do some mechanical work on the bike like removing the bash guard for an oil change, this may not be the bike for you.

Fuel tank only has the obvious bolts and two fuel lines. No hidden problems. Close fuel taps before removing the fuel lines ...

Andy
Chop your own wood and it will warm you twice (Henry Ford)
JohnXT5T
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What Bike or Bikes Do You Own?: Tenere 3AJ 1988. Tenere 700 Rallye 2022. Triumph Speed Twin 1957.
Previously Owned Bikes: BSA B40 trials, Montesa Cota 123. Honda C70. Kawasaki KH250
Location: Kent, UK & Burgundy, France

Re: Oil leak 3AJ

Post by JohnXT5T »

donnybach wrote: Fri May 06, 2022 4:17 pm Crank case breather easiest to check without removing anything. Spews it out under pressure if it slipped off. After that, clean everything, tank off and look for leaks while running from a fuel supply. Probably something simple.
Sounds encouraging.. thank you
JohnXT5T
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Posts: 17
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What Bike or Bikes Do You Own?: Tenere 3AJ 1988. Tenere 700 Rallye 2022. Triumph Speed Twin 1957.
Previously Owned Bikes: BSA B40 trials, Montesa Cota 123. Honda C70. Kawasaki KH250
Location: Kent, UK & Burgundy, France

Re: Oil leak 3AJ

Post by JohnXT5T »

motorang wrote: Fri May 06, 2022 7:01 pm It is worth noting that with any dry sump system there is a chance of the oil running down to the engine (which it only should do over a longer period of time), leaving the external oil tank with a seemingly too low oil level.

Once the engine is running, the excess oil will be pumped up to the oil tank again. This will take a few minutes and medium rpm to establish a "true" oil level, which is why you do a few things differently from other engines.

1) If the bike is new to you and you are not sure if the oil level is OK you drop all the oil (engine and tank) and refill the amount as per specification.

2) Now you know there is roughly enough oil in the engine, you always check AFTER a ride, right after switching the engine off, without letting it idle on the side stand. This is when the true oil level can be assessed.

Letting the bike sit a few minutes or idle a few minutes may change the oil level.

So what happened is most likely there was enough oil there, just not easily to be measured. So you topped up a litre, and that excess oil is now getting foamed up by alternator and crankshaft and bubbles up through the crankcase breather into the air filter, from where there is a little hose valve to let the oil drip out. Most of it will be soaked up by the foam air filter, causing the engine to stutter and run rich with some smoke from the exhaust.

I again would recommend to make a proper oil change. Drain the oil from engine and oil tank, then refill as per spec.

Remove the air filter and squeeze it dry (you can wrap it in paper towels to do so). The filter foam should only be moist, not dripping when squeezed.
If you are anxious to do some mechanical work on the bike like removing the bash guard for an oil change, this may not be the bike for you.

Fuel tank only has the obvious bolts and two fuel lines. No hidden problems. Close fuel taps before removing the fuel lines ...

Andy
Thank you for this.. I'll be checking her over in a few days.. Much appreciated comments
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