Hello.....Just bought a used 87 sportster and was changing the primary oil and didn't think twice about the drain plug coming out so easy. Checked the tension, and went to put the drain plug back in and it's stripped. I can get it tight enough, but I know that's not good as I believe pressure builds up in there. Any suggestions?
Thanks in advance...

 

I think the plug is a 1/2″-20 straight threaded bolt with a ring gasket. Have you checked the auto stores for an oversize self thread cutting plug just for this problem. That is a pretty common size unlike the newer Harleys with the MS o-ring plug. I would be more concerned with vibration then pressure. I am pretty sure the primary / transmission vents up thru the oil tank. Know they do not mix the oil but it is vented to the top there if you look at the oil routing display in the manual.

 

Thanks fior the suggestion. I'll check out napa tomorrow and see if they have something. There was no gasket. just the plug with a washer. I put on a gasket and tightened it as much as I could without it losstening up again. Lock tight isn't an option is it?

 

My '07 has an independent vent on top of gearbox. No pressure in there. I'd use some sealant tape on thread to make sure it will resist the vibration.

 

Like that white plumbers tape? Tephlon I think it is?

 

Loctite would not be my choice. The Teflon tape may just do it if you have some thread left. I use it on my tapered pipe plug in my primary, and it snugs up a turn before it normally would without any sealer. Surprised yours had no gasket. Did it have an o-ring groove? This is what is on my oil and transmission drains. My primary has the older style small NPT pipe plug

 

Thanks again. Nope. No spot for an o ring. Looked just like any other standard bolt, but it was magnetic and has the top that looks like an tire tube plug. Hope that made any sense. Had a slot that a small flat head screwdriver could get into, but there is no reason for it. I just put on an o ring onto the threads. Hoping it doesn't leak.