Another pitch (e.g., M12-1.25) oversize plug might work o.k., if an oversize M12-1.50 oversize plug can't be located.
I've seen M12 oversize oil drain plugs (NOT piggy-back; don't recall the pitch) on the rack at Advance Auto Parts stores.
I'd favor using a NON-piggy-back plug, if possible, because of the added projection of the secondary plug; that is--the smaller plug sticks out farther beneath the engine cases, and might invite damage from a rock strike moreso than the lower-profiled one-part plug.
If you're desperate and urgently need an oversize oil drain plug, you might simply canvass the auto parts and accessories stores in your area for simply, "Oversize M12 Oil Drain Plugs."
Be sure to use a good washer with your new plug; good luck!
Here's a link to motorcycle oil drain plug thread diameters and pitches:
In your first insertion, I'd recommend coating the threads and end of the plug with grease, to catch any metal shards resulting from tapping the hole to the larger size. When the plug's fully inserted, back it out and clean off the grease with any attached flecks of metal.
Proceed slowly, in, until you meet resistance, then back out slightly; repeat, until you've fully "bottomed" the plug (not too much torque, now!). Use a good washer!
If you have enough base metal left, the oversize drain plug's tapered threads will tap a new, slightly-larger hole with threads the same pitch as before. If the plug seals, you have a permanent repair; just . . . be CAREFUL when torqueing-down the plug hereafter!
Just did the oversize m12 1.5 drain plug in my bike and it worked fine. But b4 I proceed I measured the plug and it measured 12.4mm on the bottom part of the threads. Threads tapered it goes from a 12 mm from the starting point and 12.4mm at the bottom of the threads. It's a singe oversize plug that I got from eBay. I did as what Damocles advised to go slow and take ur time on putting it in. No drops or drips and plug is fixed.
A forum community dedicated to Kawasaki KLR 650 motorcycle owners and enthusiasts. Come join the discussion about performance, modifications, adjustments, classifieds, troubleshooting, maintenance, conversions, and more!