Yamaha G14 smokes Bad

[Universal_Mechanic]

If ya got blue smoke and a spark plug like that, you need rings. I always check and lap valves on a rebuild, and have never seen bad valve guides on any yamaha motors J38s and JN6s., 7s, etc Every now and then especially on the older ones, you see a cracked stem seal, but usually its just rings. Just make sure to check the cylinder wall well, have it bored if necessary. If the ridge is less than .010 ill usually leave it be, just hone it well and always check ring end gap, especially if filing oversized rings, .010-.014 is good. Last few I did were nice, no ridge, standard rings.

But anyway, they're right about compression tests not being the best way to determine if rings are bad unless you do a dry/wet leakdown test. But I don't even bother, like I said, blue smoke, dirty oily plug = bad rings. Besides it only takes like 6 hours from start to finish for a smoking yami rebuild, I don't even question it anymore, if it smokes bad enough it gets a rebuild. You could always reassure yourself and spend 15 minutes to pull the head and check the guides but even a bad guide/seal won't consume *that* much oil, and I would think if a guide was *that* bad there would be poor compression due to a hammered up seat.

You asked if the motor needs to come out, yes it does. I always just unplug/unhook everything and leave everything on the motor, starter/gen, clutch, everything, unbolt the motor mounts, lift out the whole assembly and strip it down on the bench. It only weighs like 80lbs with everything on it, not that heavy. So much easier to stand at the bench to tear it apart rather than hunched over :)

[gutterboy2ca]

Universal_Mechanic, thanks for the valued input, i'm dropping it off at mechanics next monday, he guestimated 8 hours labour, guess i'll bite the bullet and let him go for it.wonder why piston/rings is almost double for G-14, compared to like G-8 or even G-16, weird.