1986 125m valves, help needed

[fabiodriven]

You can replace valve seals yourself. It's valve seats that require a machine shop. That's probably what you're thinking of.

[mrcribbs]

02 RING SET (STD)
13011-HB6-305 001 $33.16 $24.99

www.servicehonda.com

Sorry about earlier, I thought Beatrice Cycle had ring sets for your year...

I'm currently rebuilding the top end on my '84 125M and it smoked badly. I tested compression and had 175 PSI cold so I thought it was just a valve seal but once I got it apart I really didn't see anything obvious. Turned out the rings are worn badly - .027 and .031 ring gaps. Cylinder only has .0015 wear. The valve seal was intact but is very hard. (84's don't have an intake valve seal...)

[Vealmonkey]

Do you have a valve spring compressor? That will be your big limiting factor. You can get away with not having a valve spring compressor to get the valves out, but I don't really like how you have to do that, but you can do it. But a valve spring compressor is necessary to get them back together. You may want to de-carbon everything once you have it apart and maybe relap your valves before putting your top end back together. A cheap and easy way to check valve to valve seat sealing is just to pour some water in the underside of your head and see if the water leaks by your valve seals. A small can of valve lapping compound is pretty cheap and a wooden valve lapper with the rubber ends is cheap as well, so very little cash outlay there. With your valves out you will be able to check the wear on your valve guides as well. Valve guides are kind of a pain to do yourself, but it's possible. The thing is, without all the right tools, it's usually just cheaper to have a shop do it unless you really want to invest in the tools to do it right so you don't ruin your head.

[RodKnockRacing]

I bought a nice Tusk valve spring compressor from rocky mountain atv mc

[hosscat]

probably going to just do the rings and check the valves with the water idea for now. If that doesn't fix it then I'll just take it back apart and find a machine shop to work through the valves. I'm expecting the rings to be the major cause. Thanks, for all of the help. It will probably be a couple weeks before I have the time to break it open (our snapper season just started) but I will keep everyone posted.

Thanks,

[RodKnockRacing]

probably going to just do the rings and check the valves with the water idea for now. If that doesn't fix it then I'll just take it back apart and find a machine shop to work through the valves. I'm expecting the rings to be the major cause. Thanks, for all of the help. It will probably be a couple weeks before I have the time to break it open (our snapper season just started) but I will keep everyone posted.

Thanks,

What I have learned from working on my own stuff its best to check everything when you break down an engine. But for the rings pull them off the piston and put a ring in the cylinder and push down with the piston an measure the end gap with the proper feeler gauge before you go buying new rings. no reason to waste money if you don't have too. Just my 2 cents