What model series Tecumseh 5 HP??
I have two of the HH series, an HH100 on the little wood-haulin' tractor and an HH70 on the splitter. They have been the most reliable, trouble-free and pound-for-pound the hardest working small engines I've ever owned... I've thrown away a dozen or more Briggs (admittedly, most of 'em have been the cheap, vertical shaft push mower type), but I've never tossed a Tecumseh HH series (I personally know of at least a dozen other old HH series still running strong). The HH100 is 46 years old (1968), starts every time, even at -20°, runs and idles like new, it will use a little oil if'n you're working it extra hard. The HH70 is 34 years old (1980 date code) and runs perfectly, has never used a drop of oil... but, being hooked to the hydraulics it can be temperamental to start in real cold weather (say, below 10°). The cold (and therefor thick) hydraulic oil just makes it impossible to pull over fast enough to build any compression. Normally I can pull the spark plug and dribble a little two-cycle mix in the cylinder, the added liquid helps seal the rings and build compression. But when temps drop below zero I've had to either disconnect the pump or warm-up the hydraulic fluid to get it started.
I'm not a big believer of synthetic oil in small engines, I believe keeping "clean" oil in 'em is what's important. I change oil in small engines 3 or four times a year depending on use... seasonal use engines, such as grass cutting machines, get changed 3 times, those being used year round get changed 4 times. Heck, most of 'em don't even take a full quart... why not change often and keep clean oil in 'em?? They get 5w20 in winter, 5w30 spring/fall, 10w30 summer, and I buy whatever name brand-name oil is on sale cheapest. The last few years at the fleet store it's been Motorcraft 5w20 and Kendall 5w30/10w30; the 5w20 and 10w30 says synthetic blend on the label, the 5w30 don't... (shrug)... whatever. Granddad always said, "Any oil is always better than no oil, and clean oil is always better than dirty oil." I tend to agree; clean petroleum based oil trumps dirty synthetic oil hands-down... and 80 years combined use between those two Tecumseh HH engines is enough proof (for me, anyway).
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