Difficulty of replacing a crankcase body?

[jeffyh]

Soooo... I snapped the bolt head on the front engine mount and had to drill it out. I didn't have a tap and die kit, but the soft engine let me thread it using a 10.9 bolt I got at home depot. Regardless I think I may have drilled too deep. I checked with a wire and it stops but it looks like fuel is slowly leaking out from the threads. Can't really think of anything else other than drilling too far that would cause it.

Is there a way that I could seal this up? If not, how difficult is it to buy one of these and rebuild my engine? Are there any special tools I'd need? I have a basic stuff like a ratchet set, torque wrenches, drills, etc but nothing like a hydraulic press. Nor have I don't anything of this sort before, but am a perpetual tinkerer and work on cars. I can manage everything except inner trans and engine block. Head's I'm okay with.

 

[Bikeguy Joe]

Clean any remnants of fuel with acetone or carb cleaner, and put some silicone in the hole before you re-install the bolt.

 

[crassius]

look in the ' Mounting Techniques for Bicycle Motors' area for other ways to mount the front with angle iron and suchlike - if you find another way that will work for you, then put in a bolt to seal that hole with some serious loctite and just don't use it for mounting

 

[bairdco]

You could probably find a new bottom end already assembled if you look.

Or, like above, just put some silicon or even jbwwld in the hole before you put the bolt in. Use carb cleaner to degrease it first.

 

[jeffyh]

Thanks, everyone. Will definitely do the silicon trick. I'm already using loctite blue, and it's getting past it.

Anyways, still wondering what the difficulty level is of rebuilding a bottom end and if any special tools are required.

 

[crassius]

sometimes the mains will take some real work to get them off the crank

sometimes I use a wedge in the open side of crank cheeks to hold their true if the cases need serious force to mate

all in all it can be a big project