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I have an old sears mower with a honda gcv160 engine that I rebuilt. I needed a new barrel assembly since I messed up the old one. I put it back together and it is smoking a lot. I put in new rings and piston, not honda parts but made to fit this engine. My question is did the barrel assembly need to be honed before putting in the piston and rings?

No you shouldn’t have to hone the cylinder. Two things come to mind that may be causing your problem. First, the rings may not have seated yet, which sometimes takes up to an hour of use. Second, just because the seller says the rings fit your engine, doesn’t mean they will. Wouldn’t be the first time I’ve seen aftermarket parts are not what they are advertised. Did you check the ring end gap before installing them? This is a common practice for any experienced tech will do before installing. If they are too large Installing them will lead to your problem.

Mxred06 said:

I have an old sears mower with a honda gcv160 engine that I rebuilt. I needed a new barrel assembly since I messed up the old one. I put it back together and it is smoking a lot. I put in new rings and piston, not honda parts but made to fit this engine. My question is did the barrel assembly need to be honed before putting in the piston and rings?

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If you are reusing an original cylinder you absolutely hone before replacing rings otherwise they will not seat. Also, have you staggered the gap on the rings 120° apart? Did you check the end gap of the rings before installation? New ring end gap should be .008" to .014"

If your cylinder is smooth and shiny you need to "break the glaze" oil will bake into the almost microscopic crosshatch grooves from the original honing. This is refered to as glaze and prevents the new rings from seating to the cylinder properly. The proper grit and type of ball hone is best to do the job. Aluminum and cast iron require different hones. There is also the redneck method that involves a power drill and red scotchbrite.

woodstover said:

If you are reusing an original cylinder you absolutely hone before replacing rings otherwise they will not seat. Also, have you staggered the gap on the rings 120° apart? Did you check the end gap of the rings before installation? New ring end gap should be .008" to .014"

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This is a new cylinder from the factory. I did stagger the gap on the rings and kept them away from the side where the piston pin is. I did not check the end gap of the rings before installation. Thank you for your input.

Rivets said:

No you shouldn’t have to hone the cylinder. Two things come to mind that may be causing your problem. First, the rings may not have seated yet, which sometimes takes up to an hour of use. Second, just because the seller says the rings fit your engine, doesn’t mean they will. Wouldn’t be the first time I’ve seen aftermarket parts are not what they are advertised. Did you check the ring end gap before installing them? This is a common practice for any experienced tech will do before installing. If they are too large Installing them will lead to your problem.

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I did not check the ring gap before installing them. I did not know when I put them in. I have since read that I should have done that. You are confirming that would have been the right thing to do. I was trying to save a little money with the aftermarket parts but it feels like a bad idea now. Thank you Rivets.

A brand new cylinder should come prehoned ready to fit the rings
I think some responders did not read your post fully
Now the crunch
There are a lot of different ring sections and they all have both a right & wrong way up and a right & wrong sequence
Do either wrong and it could take forever for the rings to seat
The springyness of the ring does not make the seal, it is the pressure of the air / fuel mix under the ring retying to bypass the ring that makes the seal
This is why you stagger them when first installed
BEcause of the way they work, the ring grrove cleaness and dimensions are critical
Too much side gap & the gasses pass right through and not enough and the gasses can not get behind.
I used to domassive miles on a Yamaha SR 500 and quickly found that I could only get 2 sets of rings out of a piston because of ring groove wear .