Homelite ST385 ring installation

[JohnZ]

Hello everyone. I'm a long time lurker and have learned a lot by reading perr and the new forums. I'm just a homeowner that likes to tinker.

I've got an old string trimmer model ST385 UT15040d that has low compression. The parts are cheap enough that I thought I'd pull it apart and try to learn something. The ring was free. Not much carbon on the piston, jug or output port. The jug has no vertical scoring but has horizontal lines that my fingernail will not catch. I didn't measure ring gap but it looks big to my untrained eye.

I ordered a cylinder kit and ring (it only has one) but I have a question about installing the ring. There is no index pin on the piston to keep the ring from rotating. Do I just install it and hope the ring doesn't catch on one of the ports?

Thanks,
John

[bobodu]

Yep...What else could you do???

[bgsengine]

If the cylinder has ports that the ring *could* catch in (and at least some unbroken cylinder top to bottom where there's no porting) then there really should be a ring locating pin on the piston - However they can be quite small and very hard to see - have you tried installing the ring and see if it fully seats in groove all the way around? - Or install ring and work an open end into the groove and see if you can rotate it 360 degrees..


But some machines did not (ports were too small) have locating pins, but it'd be quite rare for that.