Mack Posted July 8, 2005 Posted July 8, 2005 What the ...? Do you think this can be saved or is it time to look for a new cylinder head?
HubbardRA Posted July 8, 2005 Posted July 8, 2005 I'd grind the metal off of the piston, then reinstall the head. If it doesn't crack, then continue running it. I am currently running one that apparently had been run with a screw in it. The area where your problem is looks like it was beat on with a screwdriver being hit with a hammer on my head. My damage covers the entire flat area. Engine runs fine that way. No problems.
DanielB Posted July 8, 2005 Posted July 8, 2005 Mack, The carbon pattern on the piston looks interesting. Was this head machined down? Correct gasket thickness? Looks to me as if there might not be clearance between piston and head at TDC. or Could the head have been electrically isolated from the block causing the spark to return to the coil by jumping to the piston head? Dan
jlasater Posted July 8, 2005 Posted July 8, 2005 Looks like detonation or severe overheating on the cylinder head. You could have the 'canyon' welded up and machined back down, or just replace the head. It might be running very lean as well, evidenced by the lack of color in the head.
dlcentral Posted July 8, 2005 Posted July 8, 2005 I agree just grind er off,and run er, that motor looks to be in very good cond no excessive carbon from oil burning,etc.doncha just love them new head gaskets,, one shot thats it!
Mack Posted July 8, 2005 Author Posted July 8, 2005 Cleaned it up and put a new gasket on.Fired er up for a few seconds to make sure it run before finising putting everything back on.Of course now that everything is back on it won't fire! D***ed Briggs! May have to find a Kohler to stick in it! ;)
patrician12 Posted July 8, 2005 Posted July 8, 2005 I have never seen a Kohler do that either......the rod usually goes through the block.
msiebern Posted July 8, 2005 Posted July 8, 2005 When you find that Kohler, I will gladly take that Briggs off your hands }:) Simplicity 725 w orginal Briggs 7 1/4 - Running AC B-110 w original Briggs 10 - Running Simplicity 7014S w origianl Briggs - Running Simplicity 7018 w original Kohler - Rod out Simplicity 7114 w original Kohler - Rebuilding due to excess fog :( Simplicity 7116 w origianl Briggs - Running workhorse Ariens S16H w original Kohler - fogger Bolen G-16XL w original Tecumseh - Blown (anyone surprised) Loved the Kohler 14 horse when it was running but the 18 OHV has been a headache since day one. I know a lot of the service you get depends on maintenance. These tractors other then the Ariens and Bolens were all bought new or nearly new, (we don't get rid of good workhorses):I, and maintained on a regular schedule. I have seen the damage you show in the head and piston before and it usually comes from a screw in the throttle shaft coming out and being ingested by the intake.
maxtorman1234 Posted July 8, 2005 Posted July 8, 2005 Hmmm, The blown kohlers i have taken apart all have evidence of low(or no) oil, and have cooling fins plugged. So, when your motor heats up most likely aluminum will melt to the crank and the rod will break:o) But I havent had that problem yet. ANd, the rod dosent usually go through the block, but sometimes it does. I have come across probably 10 kohlers that have thrown rods, only 1 was through the block. And it was run with no oil. A/C 310 14HP Kohler (runs great) A/C716H 16HP Kohler (runs great) A/C 917H 17HP Kohler (runs great) Ford LGT 125 12HP Kohler (runs great) A/C 312 12HP Kohler (knocked since i got it) A/C 712H 12HP kohler (runs great) O, and a couple 4HP kohlers that run great (no briggs, because theyre crap:))
Al Posted July 8, 2005 Posted July 8, 2005 HI, Looks like detonation to me. Could be caused by carbon buildup, old or low grade fuel, timing problemm, or a lean mixture, to hot a plug can get in it also. Air leaks in the manifold or around the throttle shaft can cause lean problems. I would replace the head if it were mine. If I were to run it, I would take a die grinder and rotary file and dress the sharp edges on the pit before I put the head on. Detonation is usually accompanied by a sharp edge or a carbon particle that can get so hot it ignites the fuel mix before the plug fires it. It is these little "glow plugs" that cause problems. In racing engines the major cause is too high a compression for the fuel grade and mix, or combustion chamber shapes etc. Not likely a comtributor here. Look around the edge of the piston and you will likely see the edge of the piston pitted also. Seems like the band around the piston opposite the valves has been very hot. Al Eden
maxtorman1234 Posted July 8, 2005 Posted July 8, 2005 Could this create problems in the long run? Is it likely to happen again if its not set up right, and is it an easy problem to fix? Just wondering since I havent seen this before,
MDB Posted July 9, 2005 Posted July 9, 2005 quote:Originally posted by patrician12 I have never seen a Kohler do that either......the rod usually goes through the block. LOL;):D
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