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M18 x 1.5 brass grease nipples for unseizing pistons

Posted: Sat Oct 20, 2018 3:14 pm
by andrew
I have 3 spare and ask $3.55 each plus shipping. This is what I paid for them, just want them to find happy and useful homes! I'm based in US but these are small so I doubt shipping to UK etc would be very much, I can check if you give me a post code.

These are a perfect fit for the spark plug threads (ex 125/170/QB) and will absolutely unseize/move even the most stubborn piston with a simple handheld grease gun, as long as piston is high enough to cover the ports. My only recommendation in hindsight is to try to use the washer from a spark plug. It worked just fine without but I had to give a lot of torque to ensure it sealed, perhaps a plug washer would help alleviate any possibility of stripping the threads.

Here's a shot of one in action. I had previously given up on ever unseizing this piston, and bought the nipples on a whim for educational purposes really only to see if this technique worked. Can confirm it does and that the same piston/block is now back in service!
IMG-3199.JPG

Re: M18 x 1.5 brass grease nipples for unseizing pistons

Posted: Sat Oct 20, 2018 6:28 pm
by Charles uk
I fill the cylinder with a mix of 2-stroke oil & diesel before using a home made nipple (leaving the minimum air space), give a few pumps to increase the cylinder pressure & leave for a few days, this gets a little lube down the sides of the piston, with luck, before giving it the big pump!