crank seal leak

[2strokecook]

i recently blew up my motor, i had herd on another post that a leaky crank seal on the stator side wcould cause this, and yes i agree if it leaked it would run extremely lean... i was just curious to wheather this happened quite often because i am rebuilding and stickin money into it and haven't found the problem yet, i had a hole burnt though the piston, on the exhaust side. It got very hot and was even cracking it. But yet the other piston (clutch side) looks fine, (normal wear) my boots appear to not have an cracks that went all the way though ( replacing anyway) my jets are the same on both sides, reeds aren't cracked or chiped, just a lil comfused..... thanks

[J-Madd]

YOu need to do a leak down test. And yes, you probably have a leaky crank seal.

[2strokecook]

YOu need to do a leak down test. And yes, you probably have a leaky crank seal.

 

too late for the test it's all torn down but i am lookin for the problem..... not to many more things it could be.

[sinisterboo]

Theres plenty more it could be my friend. plugged main jet, leaking base gasket, carbs extremely out of sync, you get the picture.

[Maverick]

i recently blew up my motor, i had herd on another post that a leaky crank seal on the stator side wcould cause this, and yes i agree if it leaked it would run extremely lean... i was just curious to wheather this happened quite often because i am rebuilding and stickin money into it and haven't found the problem yet, i had a hole burnt though the piston, on the exhaust side. It got very hot and was even cracking it. But yet the other piston (clutch side) looks fine, (normal wear) my boots appear to not have an cracks that went all the way though ( replacing anyway) my jets are the same on both sides, reeds aren't cracked or chiped, just a lil comfused..... thanks

 

Hey let me know if hteir is a seal tgo in between to two halfs of hte engine. I just put it together and am new to banshees and used red silcone high heat gasket maker. Leaks like a siv now and blows oil inot stator so it will hardly operate. If their is a seal where can I get one besides Yamaha direct?

 

Thanks wade

[Maverick]

YOu need to do a leak down test. And yes, you probably have a leaky crank seal.

I asked another post but you have some serious machiens. Is there a gasket between the two motor halves in the bottom end?

 

THanks

 

wade

[sinisterboo]

No gasket, just yamabond sealant......

[2strokecook]

Theres plenty more it could be my friend. plugged main jet, leaking base gasket, carbs extremely out of sync, you get the picture.

well carbs were damn close, (if they were off). and the jets weren't clogged or anything, i took that all apart, (shee striped)

[278]

Yeah Wade no gasket just some sealant. Did you make sure you cleaned the surfaces before you applied it? Try some blue RTV silicone gasket maker, it's made by Permatex you can find it at any auto parts store and it works so great that I've used it as a quick fix to seal a blown gasket on the bottom of a cylinder

[deckheight]

Do yourself a favor... Use Yamabond or 1211 to mate the case halfs...

[mopar1rules]

i use the threebond 1104, which is now called 1194...its only $6, versus the $20 for the threebond 1211 :smile:

Edited October 18, 2008 by mopar1rules

[pittss1c]

do people replace crank seals regularly to prevent this? (I have heard of many bad crank shaft seal melts)

How often should you replace them?

[mopar1rules]

replace them every time the cases are split, or one becomes leaky.

 

if you put in new crank seals...are they in the right way?

Edited October 18, 2008 by mopar1rules

[dajogejr]

Make sure both case half gasket surfaces are clean, and apply a liberal coat to BOTH halfs, then mate them together and tighten them.

 

As said, Yamabond 4 or Hondabond 4 (if you can find it) or any other fuel proof semi-drying gasket will work, like the three bond types above.

 

RTV will cause issues....