My Banshee exploded a piston, so there are lots of metal shavings in the cranscases now. Is there a way to get them out without splitting the cases? Also, how much work is it to split the cases? Are any speckial tools required? I've never done it before

Thanks for any info!
Mike

 

Make sure it is the pistion. Check the crank while you have it apart. U can probably get a wet vac and suck up the metal with a smaller attachment. I had that problem with one of the circlips during a rebild. I dropped it in the case. Nothing a wet vac couldnt handle. Good Luck

 

Your in luck with the fact Banshee cases are clam shell cases (opens top and bottom instead of side to side). You should really find out what caused the piston to explode first. Fix that problem then start at rebuilding. If the cylinders need to be bored due to scoring ship them off. Order a piston set (always get a set that are of matched weight). I'd replace the crank main bearings since you will be opening up the cases to make certain you have every last bit of piston out of the bottom of the cases. I'd also replace all the seals since all it takes is one leaking to cause your motor to blow again. Last is a new gasket set. Why did your Banshee blow anyway???

 

Thanks guys. I bought the quad this way, so I don't know what was wrong with it. So there aren't any special tools required to split the cases? What about the transmission? Will that fall apart when I split the cases? Just wondering how much work this is going to take

Thanks!
Mike

 

I just did this very thing... here is EVERYTHING I KNOW..

You need one special tool, flywheel puller. You can buy one from any yamadog dealer for about 10 bucks. With out it it's almost impossible to jerk the flywheel without damaging it.

The cases split real easy.. just unbolt the 20 or so bolts from the top and bottom of the cases. Pull the top case OFF, it will leave the transmission 100% where it should be, and don't mess with it.

You must pull the entire clutch assembly, there's a plate underneath it that bolts to the top and bottom of the case, you have to take that off. You have to pull the flywheel and stator assembly, it bolts to both the top and bottom of the cases.

Check your bearings on your crank. If they sound bad or don't roll well, you'll need either a new crank or a rebuild. This isn't something you can do at home cause the center bearings are pressed on and the crank its all one peice. I was quoted anywhere from 365 to 580 to rebuild the crank. Then I called Magic Racing, and they sell the Wiseco Crank, with all new bearings and "Hot Rods", for $399. No brainer in my mind, completely new crank and no time delay on the rebuild, I had it shipped to my door with new seals and shipping for $422.00

You'll need some yamabond #5 to reseal the cases, it can be purchased at the yamaha store for about $7.00. It's really straight forward and easy, if you take your time and have a manual.

One thing I will say, that tripped us up on my rebuild, when reinstalling the crank there is only *ONE* main crank clip (keeps the crank from rocking or sliding left to right). It looks like there should be 2, as one is a half circle. but there isn't one on the top half of the crank, even though it's grooved for it. Funky, but you'll see it as you pull it apart.

Obviously if you have too much piston to sidewall clearance you'll need to bore out your cylinders. Make sure who ever does your bore job matches the bore to the pistons. This is the only right way to do it, but yet some places will bore without matching the pistons, and they are sure to mess up your banshee motor once again.

While I was in mine, I replaced clutches, reeds and some other little junk along the way, easy to do while you got it all apart.

Thanks my $.02 on the rebuild.

Brad

 

did yall change out the rubber seal on the right side of the cases, that the crank goes in???

 

Just my $.02 here.. but always replace BOTH seals on the crank if you split the cases. Remember 2 strokes are sealed systems that require pressure in the crank to run correctly, so why take chances with a bad seal when new ones are only $14.00

Brad