Page 1 of 1

spark plug fitment

Posted: Sun Oct 23, 2016 4:39 pm
by matt glascock
Hi Everyone, here's the scoop. After a new top end install and oil injection system repair on a '75 Toad, I was running 32:1 premix during break-in period and to confirm proper injection operation. After run-in, I changed the plug (NGK B8HS) and have been running straight 92 octane nonoxygenated pump gas. It ran "too well" suggesting a lean condition. Leak-down test confirmed leak at the spark plug. I used the old stand by "finger tight + quarter turn" method on the install. After the leak down test, I applied the wrist torque wrench which properly seated the plug thus ending the air leak and restoring proper engine operation. The question at hand is: what is the best, safest way to install a spark plug to insure proper seating without overdoing it and compromising the function of the spark plug gasket? As always, thanks to all!

Best,

Matt

Re: spark plug fitment

Posted: Mon Oct 24, 2016 3:54 am
by thrownchain
I just snug it down with a plug socket on a 3/8 drive handle. No need to do any more than that, just snug.

Re: spark plug fitment

Posted: Mon Oct 24, 2016 6:17 am
by viclioce
I do it the same as Thrownchain Matt. As little big as its wrist tight, that's good. Just don't repeatedly overtighten and flatten out the washer. If you do, just change the plug again. ; D Victor

Re: spark plug fitment

Posted: Mon Oct 24, 2016 9:37 am
by matt glascock
Good call. Thanks fellas!

Best,

Matt