Leak test failed, crank case crack

blasterplus6

New Member
Feb 24, 2009
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crack1.jpg
crack2.jpg


Strange idle made me leak test the blaster. Found this crack in the bottom of the crank case. Motor has maybe 20 hours on it since last rebuild.
Seems like i need to split cases and inspect right?
coors light is telling me to jb weld it, lol.
 
Rock or something must have hit it. Do it right the first time and fix it properly. but if I had a couple booze in me I would also be looking at the JB weld solution lol! If you have access to a welder it wouldnt be that hard of a fix to know its done properly.
 
The engine is coming out this weekend. I gotta see how deep the crack is.
For the record, i was kidding about JB weld.
 
i think its time for a new case half.

will there be any issues with the new case half lining up with the old? is it ok to mix and match cases?
 
Do you think the hole could have been made by the yamabond in the screw hole having nowhere to go when the screw was tightened?

anyway, the new case half came in yesterday, seems to line up perfectly!!
i will be rebuilding the motor this week and promptly leak testing it.
 
did you find the displaced chunk ?
it may be in the pipe.
the way it broke, makes it look like there is a screw head stuck in the bottom of that divot !
 
Do you think the hole could have been made by the yamabond in the screw hole having nowhere to go when the screw was tightened?
I have seen that a few times before, the bolt hole being filled with bonding or Loctite, when the screw gets tightened up, the material is pressurised and has to go somewhere!