Bullet Train drivetrain/crank seal

[RKmotoriedbikes]

I finally got my BT running and was running it all day today with no problem until this evening, it started smoking oil big time and I lost drive power. I'm wondering if maybe the drivetrain oil is leaking into the engine and the seal went...the drivetrain oil is black too which it shouldn't be so it must be a seal gone I think...Does anyone know about this or had this problem before. Thanks

 

[Chainlube]

Is this a new engine, or new to you?

Just as a precautionary measure, throw a wrench on your head bolts and see if they are loose. They will loosen off a bit for the first few heat cycles.

 

[RKmotoriedbikes]

Is this a new engine, or new to you?

Just as a precautionary measure, throw a wrench on your head bolts and see if they are loose. They will loosen off a bit for the first few heat cycles.

Engine is new but I am not new to motorized bikes. I do know about the head bolts but that's not the problem.

 

[DAMIEN1307]

Whats up with that exhaust sticking straight up in the air instead of straight down like it was designed for so the motor can run efficiently???

 

[RKmotoriedbikes]

Whats up with that exhaust sticking straight up in the air instead of straight down like it was designed for so the motor can run efficiently???

Well it runs great and just how i had to put it until I can custom make the exhaust for this bike but really it doesn't matter which way the exhaust flows as long as it flows.

 

[DAMIEN1307]

it started smoking oil big time and I lost drive power.

Well it runs great and just how i had to put it until I can custom make the exhaust for this bike but really it doesn't matter which way the exhaust flows as long as it flows.

OH, Ok then...I am happy it is running great for you then...From the sound of it when you opened this thread, I thought you were having trouble...Guess I was mistaken...lol.

 

[RKmotoriedbikes]

OH, Ok then...I am happy it is running great for you then...From the sound of it when you opened this thread, I thought you were having trouble...Guess I was mistaken...lol.

I am but it's not exhaust that's doing it...the BT motor has an automatic centrifuge clutch which requires you to fill it with 10w30 or 10w40 which I did but that oil is now black and my engine is smoking oil so I believe the seal must be gone...I haven't takening it apart yet to see so I'm asking if anyone has had this problem or seen this before with the BT motor

 

[ImpulseRocket]

OH, Ok then...I am happy it is running great for you then...From the sound of it when you opened this thread, I thought you were having trouble...Guess I was mistaken...lol.

Hey, some of us just like the smell of 2 stroke exhaust more than you. Just makes it convenient.

OP. I think your instincts on it being that inner seal to the crank being bad are right. My memory is a bit rough, but I do believe the shaft is splined on that side of the BT80 crank, and if the splines were forced over the seal surfaces dry it could have potentially made a small cut in the seal surface and it could have a leak or two, or had accelerated wear. This is a very common issue on countershaft seals on motorcycles (splined shaft the sprocket bolts to) for the same reason.

I would say to contact whomever sold you the engine and see if they can at least offer you insight or maybe a free set of seals. If they do, when you install them, coat the inside of the seal lip with grease when going over any splines and be gentle.

 

[RKmotoriedbikes]

Thank you,

I Did contact the place that sold me the engine they said to diagnose the problem and they would replace the parts I need for free. If you do look at the picture you can see the oil that was spiting out over the exhaust.

 

[ImpulseRocket]

Thank you,

I Did contact the place that sold me the engine they said to diagnose the problem and they would replace the parts I need for free. If you do look at the picture you can see the oil that was spiting out over the exhaust.

Easy way to know. Does that drive gear oil smell like fuel? If it got that dirty so quickly I would imagine it should have a strong fuel smell to it.