Anti-smoking (engine) campaign: 1450

sawdustdad · #1 12-27-2013, 11:14 PM

Finally have the time to pull the engine from my 1450 to diagnose the excessive oil consumption. Here are some pics. Haven't mic'd the cylinder yet, but there is quite a gap between the piston and the cylinder wall at the bottom of the stroke on the valve/carb side of the cylinder. Several of the head bolts were pretty loose, too, so it's definitely time for some work.

The cylinder is not scored anywhere that I can see, but there is a lot of oil on top of the piston, and this is just from running it up from the storage building up to the workshop, a couple hundred yards. I think it's just the piston that is worn. It was burning 8-12 oz per hour--in other words I was was adding a pint every time I cut the grass! Talk about a smoke screen!

I found a machine shop in town (NAPA shop/Richmond) that can machine the block. So I've got to tear it down to the bare block, and that will be a new experience for me. I've replaced a piston before, but never totally stripped a block. I may be posting some questions as I make some progress on this. I'll post the results of my cylinder measurements once I get the piston out.

I'd be interested in any tips/tricks that you guys can recommend for things to definitely look out for or change as I reassemble. I'll buy a rebuild kit off ebay once I find out the proper piston size (if it needs to be bored). If it has balance gears, I'll remove them, but not sure these engines even have them. I'll see when I get the oil pan off. What upgrades would you recommend?

finsruskw · #2 12-28-2013, 09:10 AM

Well, you are one step ahead of me! At least it looks like all your head bolts came out w/o busting any! I just did a 14HP last spring. The machine shop (NAPA) and parts bill total was $233 and they had to remove 1 broken bolt.

Inspect your oil pan closely for stripped threads, cracks and worn mounting pads. I had mine milled flat and added flat washers to get it back up to where it belongs. This would be a great time to upgrade to a cast iron pan if yours happens to be in bad shape.

Have your shop check for proper cam shimming and run-out. I have been told that is the source for the "Kohler Knock" which I have in mine as well as a 1250 that is next in line for re-hab. Keep us posted!! and good luck!

dvogtvpe · #3 12-28-2013, 05:49 PM

judging by the wear that I can see in the bore it'll need to go .010 os

sawdustdad · #4 12-29-2013, 09:31 AM

You may be right, but the pictures can be deceiving--the cylinder walls are like a mirror and there are lots of reflections in the pictures that look like defects in the cylinder walls that are not there. I haven't measured it yet, so it may be out of round or otherwise worn, but it's not scored or damaged.

J-Mech · #5 12-29-2013, 04:10 PM

Quote:

Originally Posted by sawdustdad

You may be right, but the pictures can be deceiving--the cylinder walls are like a mirror and there are lots of reflections in the pictures that look like defects in the cylinder walls that are not there. I haven't measured it yet, so it may be out of round or otherwise worn, but it's not scored or damaged.

I agree with Don. It's not that we can see defects... It's the fact that it is that shiny along with the absence of the crosshatch. A cylinder wall isn't supposed to be reflective like a mirror. The way the carbon trail goes from the cylinder to the valves indicates it is burning oil. The color of the valves indicates that it had low cylinder temperatures, caused either from a rich carb setting or from low compression. From the look of the cylinder, I'm saying slightly low compression. From the look of the top of the piston, when you get it out, I think you will find, that compression was going past the top ring and on into the second. It will be black between the top and second ring. I also think you will find the bore to be a little egg shaped.

sawdustdad · #6 12-29-2013, 08:14 PM

I got the engine dis-assembled tonight, and mic'd the bore at 3.502 to 3.503, so it's at the wear limit. Very light scoring (can't feel with fingernail, but visible with a raking light). Somewhat egg shaped.

The piston is very interesting. See pics. How does the top edge of the piston get damaged like?

The block's going to the machine shop tomorrow.