Holes in Right side egine cases

[dirtydeezl]

I now have 2 dead blasters with holes in the right side engine cases under the crankshaft. One of them lost the top end and took the case with it. The other hasn't been disassembled yet but still has compression. Assuming the skirts didn't come apart, what causes this happen?
Obviously if the piston grenades on the second one I'll assume a chunk of piston was the culprit. The first blaster just stopped dead and the one with compression bogged out like it just ran out fuel. Any insight would be immensely appreciated. Thank You.

 

[best]

The skirt broke off the intake side of the piston. Very common.

Here is what my son did. Still running all these years later:

http://www.blasterforum.com/threads/jb-welding-holes.45887/#post-575699

 

[dirtydeezl]

Wow, I'm shocked that worked! quite an enterprising solution. I still have to pull the engine and break it down to see the extent of the damage internally. it'd a minor consolation that it's a common occurrence, lol. I've found a machine shop that says they can welding it for around a hundred bucks, do I think I'll give them a try. Gonna put in New bearings and seals while I have it gutted to reduce the risk of it blowing up on me again soon. thank you for your reply.

 

[best]

Yes, it is still working something like 5 years after, 30+hp, crazy kid running full tilt every ride.
When you hear the piston slapping it is time to pull the cylinder and figure it out.
Max revs and piston slap = broken skirt = holed case.

Steve

 

[dirtydeezl]

Didn't notice any slapping. it just bogged out like it was out of gas. was just weird. looked on eBay and picked up a case half for $70 and a complete gasket/seal set. now I gotta get it apart to size the piston.
I'll eventually get the broken halves welded for spares.

 

[dirtydeezl]

Got it apart today. intake side skirt like was predicted. good news was that it just clean through and didn't bust up the case. I'll have it repaired and keep it as a spare.

 

[best]

I just bought a 2003 Blaster tonight and you can be sure one of the first things I am going to do is pull the jug to check on piston condition and clearance. This is the Blaster's main weakness.