yungman, Your statement about a lean condition from a partially blocked carb causing problems is true and quite common. Usually a lean condition on a governed engine like a mower is apparent from loss of power. Slightly lean conditions may not be so apparent and can cause problems.Your assumption that it is detrimental only to 2 cycle engines is not quite true. Both 2 and 4 cycle engines are affected by lean conditions. An lean carb causes the mixture to burn much hotter just like a cutting torch burns hotter when the oxygen is increased. This heat can damage either 2 or 4 cycle engines in different ways. 2 cycle engines that are too lean can burn a hole in the piston or piston siezure can occur among other things. Four cycle engines that are too lean can burn exhaust valves and seats and possibly overheat and cause the rings to lose their tension. Your statement that people may be "out to lunch" or "doped up" is sad but true. Most of the failures that I see are caused by user neglect or abuse. Other failures that are common are what I call planned failures like ignition coils, soft metal cutting blades that wear too quickly, etc. etc. Manufacturers design acceptable failure rates into certain parts that nobody else makes. CD ignition coils are a good example. They are propritary parts that usually fail a few years out of warranty and cost about triple the money that they should. What manufacturer wouldn't want to sell a $50 ignition coil for every mower they have sold at some point in the future? Sell a million mowers and sell that many coils. What a windfall!! Motorcycle manufacturers are notorious for doing that with all kinds of cd packs, voltage regulators, pulser coils, switches, and relays. Sorry I got a little off track....

Information for consumption. Honda/Yamaha/Husqvarna/KTM/Suzuki/Kawasaki They all produced extremely high output 2-stroke racing engines in their off-road motorcycles, and these engines were put in some of the most grueling conditions you could imagine. Virtually ALL of them recommended 20:1 or 24:1 mix ratios. What the actual FACTORY mechanics did at racing events was very telling. Their teams (admittedly not running "stock" engines) but were running engines putting out even MORE power for the displacement class followed the same rules. 1) The higher the RPM's the engine turned the more oil they ran in the fuel. (e.g. a 125cc machine that routinely lived in the 10,000 - 13,500rpm range ran 20:1 or 24:1 -- The 250cc engines that ran between 6,500 and 9,000rpm ran 32:1 or 40:1, and the Open Class machines (251cc and up by AMA but they were all 400+cc engines, usually 465's, 490's, or 500cc) ran 50:1 or in some instances if the temps were cool and the loads light on the engine they ventured into the 70:1 range.) (2) Additionally Husqvarna did some testing in the mid 70's that was also very interesting. They put 3 identical stock engines on a dyno and ran them for several days at varying RPM and load conditions. Then both motors were torn down and inspected. The engine running CASTOR based oil had the least wear, followed by the synthetic oil, and finally the engine running standard 2-cycle oil. (3) A second test they performed was to run synthetic in 2 identical engines and one was run at 24:1, the other was run at 50:1 The engine that ran 24:1 had less piston skirt wear, and less rod bearing wear, but had the same main roller bearing wear as the engine run at 50:1. I personally ran my 125cc race bikes on synthetic Yamalube-R at 24:1 or ran Bel-Ray MC1 at 24:1 even though Bel-Ray claimed it was a 50:1 oil. The 250's I ran 32:1, and the brutal 500cc machine ran 50:1. The plug reading will tell you a lot. The insulator should be light tan in color. If it is white you are too lean, dark, black, or oily, and you are too rich. Changing the oil/gas ratio DOES affect the jetting settings so changing ratios will likely require carb adjustment. If you are fouling plugs then you have the fuel/air mixture incorrect for the gas/oil mix you are using. Manufacturers intentionally make the low rpm pilot jet on the rich side (so they start easier) and excessive idling will foul the plug. I am not sure if there is a low speed adjustment on the carb you have, but if you constantly foul plugs you may want to lean that out a bit, again the plug condition will tell you.

Wow. What a great outcome. You two are blessed. Really? What perfect timing!!! 'Mom' has Heart Failure, Afib with renal damage. She has been under the weather for three weeks... Had to run her to hospital for dehydration shortly after my Florida trip. We had an Eco cardio gram last week but still waiting to hear from the Doctor (!!???). She is always confused, doesn't walk well (some days are worse than others) and hates drinking fluids. I have to force her to drink while I stand and watch her. Stroke and dehydration often mirror the same symptoms, as far as I can tell. Can't wait for the Dr to call. I phoned him twice Friday but he didn't respond. I'm frustrated because they canceled her first Cardio gram and pushed it out 9 days. She had it last Tuesday and I have yet to hear anything... We had a gastro bug go through the house Friday and Saturday. I was only able to bark orders to DH. " Make her drink pedalite.,". "Give her water and watch her dink it..." "What color is her urine?". Poor DH. Today she is still dehydrated but holding everything down. Feeding her celery and other water bearing foods along with Smart Water. Sorry to take over the thread but I am wondering if anyone can tell me how to know if it's a stroke or dehydration? It seems dehydration can lead to stroke... Also, she is taking water pills for her heart. Seems like an oxymoron to make her take water pills when she is dehydrated... (So many questions for the absent Dr.)

Thank you for posting this. May I add another warning. Don't wait till all the usual symptoms are noticed. My DH came home complaining of being a "different" tired. He had been putting in twelve hour days at work. I was a nurse and gave him a basic neurological exam which was negative. No headache, blurry vision, loss of strength, speaking problems etc. I sent him to bed. The next day he said he felt better but by noon said he was tired again. This time, confusion was the only obvious sign but too late for TPA. Turned out to be a relatively large stroke without normal presentation. Ten months of rehab could have been shortened if only I had been more on my toes. He had a great immune system, never sick, never had regular check ups. Lesson learned the hard way.