A perplexing problem - Page 3

J-Mech · #21 06-21-2016, 01:35 PM

If you used the gaskets over, good chance there is a leak.

mrjeep81 · #22 06-21-2016, 01:41 PM

Never assume a switch is ok. My snowmobile was giving me hair raising fits last year, (which, by the way, ain't easy with a helmet on), was intermittently dropping a cylinder then start running fine again. I'd like to say simply because I'm a genius, (but I ain't much for lieing) I reached down and wiggled the ignition key while moving along at, oh, about warp factor 3.38, and sure enough cylinder dropped, came back, dropped again. New switch for me, problem gone. These are old machines, change it, if it ain't bad currently,,,, it will be eventually.

REDDHOGG · #23 06-21-2016, 09:41 PM

Possible valve springs??

J-Mech · #24 06-21-2016, 10:39 PM

If any of the valve springs were broke, it would miss all the time. I have yet to see one that's weak.

john hall · #25 06-22-2016, 07:11 AM

Quote:

Originally Posted by J-Mech

If any of the valve springs were broke, it would miss all the time. I have yet to see one that's weak.

Actually, its possible to have a weak spring. BUT, its HIGHLY unlikely. The tractor dealership dad worked for had a basically never used gizmo for checking valve springs. I guess somewhere deep in a service manual there is a chart for spring rates? This tool may have been a left over from the IH truck shop they used to have. One of our farm tractors had to have new valve springs during a major rebuild, don't recall ever having to change them on anything else.
I can't really see a weak spring causing the issue that is being discussed on the lawnmower once the engine gets hot. I suppose if a spring is weak and a valve stem is binding slightly once the engine is warm, the two together could combine to produce a "lazy" valve effect.

J-Mech · #26 06-22-2016, 10:35 AM

I know all about springs, John. I even have the tool to test them. I'm saying, I have yet to see a Kohler with a weak one. I've seen other motors with weak springs, but that kind of issue usually doesn't show up until higher RPM than these engines run.

john hall · #27 06-22-2016, 09:26 PM

Quote:

Originally Posted by J-Mech

I know all about springs, John. I even have the tool to test them. I'm saying, I have yet to see a Kohler with a weak one. I've seen other motors with weak springs, but that kind of issue usually doesn't show up until higher RPM than these engines run.

Thanks for being more clear, I was getting a little concerned!

Ken52 · #28 06-26-2016, 05:51 PM

I've been busy with some other things lately and haven't had a chance to work on the tractor. Thanks for the comments; I'll be back working on it in a couple of weeks.

Ken52 · #29 08-28-2017, 10:46 PM

Just thought I'd give a followup post about my 'perplexing problem' tractor.

So here we are a year since my last post on this subject, and several years after the problem first surfaced. I have been mowing with the Cub Cader 1862 all year and it has been running OK, and has not exhibited the issue with running really rough about every 5 - 10 minutes. So what made the difference? I'm not 100% sure, but I have been running it at a reduced RPM. The Hi idle on my tractor had been running just over 3000 RPM, and I arbitrarily lowered the RPM with the throttle lever to around 2500 RPM this year (checked with an electronic RPM sensor). I don't understand why that would make a difference, but it has. Perhaps the governor likes that RPM better? I had been thinking about getting rid of the tractor because it was so frustrating, but I guess it wants me to keep it around a little longer.