rebuilding 4 strokes
- Thread starter Don206
- Start date
Too much unknown to answer well. Did you hone the cylinder? Did you stagger the ring gaps? What did you set the ring end gap at? What clearance existed between the piston and the cylinder wall? Not lapping the valves wouldn't cause smoking, just loss of compression.
Maybe the rings need time to seat into the cylinder wall. If so, the smoking should reduce over a short period of time. Sorry I can't do better than that.
Maybe the rings need time to seat into the cylinder wall. If so, the smoking should reduce over a short period of time. Sorry I can't do better than that.
While I have never done the rings on a 142F, every engine I have rebuilt, 2 stroke or 4 stroke, the piston rings have a specific top and a bottom to them. You need to be sure that they are installed correctly. Installing them up-side-down can cause excessive oil consumption as while they are scraping oil off of the cylinder wall they cannot keep the oil below the combustion chamber.
Another thing that you will be fighting is the cylinder. When the engine is brand new the honing process leaves a cross hatch finish on the cylinder wall.
This finish serves 2 major purposes:
1: The valleys in the cross hatch finish trap oil for proper lubrication during the break in process.
2: The peaks in the cross hatch finish act like a file that perform final shaping of the piston rings and conform them for a near perfect seal between them and the cylinder wall.
A light honing of the cylinder will greatly improve the break in of the new piston rings.
Obviously worn out valve train can cause oil consumption too, but you can typically see the oil trail going down the valve stem and crusting on the valve head if you look inside the cylinder head port. Also, on the intake side the port walls will have an oily residue all over it near the valve pocket.
Another thing that you will be fighting is the cylinder. When the engine is brand new the honing process leaves a cross hatch finish on the cylinder wall.
This finish serves 2 major purposes:
1: The valleys in the cross hatch finish trap oil for proper lubrication during the break in process.
2: The peaks in the cross hatch finish act like a file that perform final shaping of the piston rings and conform them for a near perfect seal between them and the cylinder wall.
A light honing of the cylinder will greatly improve the break in of the new piston rings.
Obviously worn out valve train can cause oil consumption too, but you can typically see the oil trail going down the valve stem and crusting on the valve head if you look inside the cylinder head port. Also, on the intake side the port walls will have an oily residue all over it near the valve pocket.
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Your assumption that a Huasheng 50 cc has a chrome plated cylinder is
probably incorrect.
Honda GXH 50 cc have an iron liner and the Huasheng clones do too.
One guy here did get a chrome lined Titan from Dax but I have never
heard that Huashengs have chrome plated bores aside from that.
I stand corrected and enlightened. Thank you MotorBicycleRacing!
I was under the impression that the Hondas were lined and the HuaShengs were plated.
Sorry for the bum info, Don206! I edited my post to correct my bad info.
I vote for performing a light honing in the cylinder and creating a cross hatch to break in the rings properly.
I was under the impression that the Hondas were lined and the HuaShengs were plated.
Sorry for the bum info, Don206! I edited my post to correct my bad info.
I vote for performing a light honing in the cylinder and creating a cross hatch to break in the rings properly.
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