Page 1 of 2

piston ring is tight?

Posted: Sun Aug 04, 2013 9:29 am
by jfw
2003 Bullet 500

Long story but I'm trying to fit a new set of piston rings to an old standard 500cc piston. Even thought the piston is clean one of the new piston rings, the thicker oil control one, is too tight in there. The old one is a bit grotty but cleaned it and put it back and it's tight as well. Is there any trick to making this work or is it just a problem with fractions out?

I should say that I normally have a higher compression piston in there and had the bike stripped last weekend checking it over but broke a ring re-assembling. Ordered up the wrong piston rings so just to get on the road was going to put the fresh std rings on the old standard piston. Don't think that looks like happening at the moment.

I have cleaned up the old ring and popped it on but it's tight in spots as well. It just seems like the groove, in the piston, is just a bit tight for the ring in some places. Might have to leave it and wait to get proper rings for my higher compression piston.

I cut a piece of the old piston ring so I could run it around the groove to clean that out but even that short piece gets stuck in spots and it's not like there's dirt in that spot. The groove is clean metal and still I can't push the ring past the spot.

I'm sure it's a none starter and I'll have to wait for proper rings for other piston but thought I'd ask on here. There are many wiser heads then me here. Your words of wisdom would be gratefully received. ;-)

piston ring is tight?

Posted: Sun Aug 04, 2013 9:35 am
by Alan (Lancashire)
STOP: take a close look at the piston.

indian made pistons are known for collapsing , you may have spotted the start of this

piston ring is tight?

Posted: Sun Aug 04, 2013 9:38 am
by Norm
First sign of a failing piston is the oil ring gap closing up, piston crown is only supported by the 2 sides and gets hammered down and grabs the ring, ring cant move freely and with the piston going up and down it pulls the top off

piston ring is tight?

Posted: Sun Aug 04, 2013 10:41 am
by jfw
Oops sounds quite serious. Good job I replaced that piston ages ago with the higher compression one. Thanks a million lads for your help I'd be lost without you. I'll just have to wait for proper rings for my piston.

piston ring is tight?

Posted: Sun Aug 04, 2013 3:43 pm
by Alan (Lancashire)
umm , your first posting says "but I'm trying to fit a new set of piston rings to an old STANDARD 500cc piston"

now you are saying "Good job I replaced that piston ages ago with the higher compression one"

please make your mind up!


piston ring is tight?

Posted: Sun Aug 04, 2013 4:00 pm
by Norm
Hi Alan, you just have to read the original post again slowly I know it is a bit confusing

piston ring is tight?

Posted: Sun Aug 04, 2013 4:14 pm
by Alan (Lancashire)
yup sorry norm , very confusing ,

however if a ring is tight on a std piston , I agree with your thoughts

piston ring is tight?

Posted: Sun Aug 04, 2013 10:39 pm
by Alan R
Hi guys--------------- Yes, SCRAP IT ASAP !!!!!!!! or else THIS might be your destiny}----------------------------------Image --------------------------------------------------- SCARY MOVIE, EH ????

piston ring is tight?

Posted: Mon Aug 05, 2013 5:19 pm
by Midge
He He, thats mine! A year on now and I can report that all is well, it has never been so well behaved. Before the piston decided to seperate, power was low, it started to smoke now and again and after a run it sounded.. well..ill I wish I had taken advice from here and replaced the piston and rings as soon as I noticed something was wrong, but thats not what us blokes do is it?

piston ring is tight?

Posted: Mon Aug 05, 2013 5:54 pm
by Beezabryan
That has to be a photoshopped photo. ... It must be because one of our Hosts employees told me in no uncertain terms that it does not happen.