Any one had a stripped thread in a bolt hole on the crank case,

the last bottom bolt on my crank is stripped, and it leaking oil,

was looking at an insert of helicoil kit.

anyone got any recommendation on best way to repair?

Thanks

Can you take a photo?

I wouldn't recommend a helicoil on anything that takes a high load (are you talking crank, or crank case cover bolt?), but that is my conservative first instinct. Having said that, my old head has a helicoil in one of the plug threads, but they don't take a high torque load. Also, if you're talking a bolt on the edge of the crankcase, there isn't enough meat there for drilling for a helicoil, you'll only get one chance.

Option 1. is to have an ally welder fill the hole with weld, drill and re-tap.

Option 2. You used to be able to buy a loc-tite product called 'thread repair', you put it on the bolt, and put the bolt back in place and it sets like half chewed weetbix on your best work shirt (but you can't overly tighten the bolt). Don't know if this is still around.

Option 3. Not sure if the bolt is an M5 or M6? You could just use a tap for a bolt 1mm larger and then use the appropriate bolt. (Unless its an M6 already, cos I've never seen an M7!)

I'd investigate option 3. Option 1 is just an arse of a job, and option 2 is generally just for selling something to the next guy so it's his problem......

Possible somewhere between M4 and M6 lol

sorry crank case cover bolt, i would leave it, but it leaking oil where the bolt is missing.



was was thinking for get getting that that spray gasket and make sure the other bolts are tights. would do it , but im not sure.

It would be a M6, helicoil will be fine I use the RECOIL kits nice quality and never have any problems with them. My opinion is its better than original as you will have steel running on steel with the forces spread over a larger area.
As for welding the heat could change the temper of the alloy and you'd have to drill and tap a harder metal that is surrounded by softer metal.

Go easy on the drill !