750 is 12 mm. Take an old spark plug, grind the crimp from around the porcelean to remove it, and use the threaded portion by soldering or brazing your required fitting to it. I put about a 4 inch nipple in it to clear the head, then I use a quick disconnect to fit my compression or leakdown devices. Make one for each vehicle you have, cars, etc. Put a too-small o-ring around the threaded area instead of the washer, and you can screw it in and remove it by hand, while still getting a good seal.
Roland ----- Original Message ----- From: "Vince Strazzabosco" <[EMAIL PROTECTED]> To: "Multiple recipients of list" <[EMAIL PROTECTED]> Sent: Sunday, October 05, 2003 9:08 PM Subject: Spark Plug thread Sizes > As I chase down the bits needed to do compression tests on my fleet > of old Hondas, I find the local auto parts stores don't have adapters > that fit into the spark plug holes on my CB500/CB550 and CB350/4. > > Anybody know what size these are? I'm guessing 12mm.... > > Thanks, > > vince > Naperville, IL > > __________________________________ > Do you Yahoo!? > The New Yahoo! Shopping - with improved product search > http://shopping.yahoo.com
