Your mower has 4.5hp Suzuki 2 cycle. Toro has always specified 50:1 from the first Suzuki in 1983 until they discontinued the 2 strokes in 2004. They also specify TCW3 oil. Nothing wrong with a better synthetic oil, or a higher speed air cooled oil, but on the other hand Toro and Suzuki knew what they were doing spec'ing TCW3 and the engines have run successfuly for more than 20 years. TWC3 is designed for water cooled outboards, but make sense for the Toro/Suzuki. The engine governed at 3000 to 3300 rpm, and not the 8,000 to 12,0000 rpm common to hi-perf chainsaws and string trimmers. It runs much cooler than the little screamers. I would not go any richer than 50:1 or you will simlpy carbon up piston and muffler that much faster, and you risk having a ring stick. On the other hand I would not run leaner than 50:1. I'm sure someone will chime in that they use Amsoil or something else at 100:1. Go ahead at your own risk. But if you throw a rod, or sieze the piston, try to get that guy to now answer your email.

deeredoctor: --------------- That was helpful ... I wish it was just a bit warmer outside (n.nj) Id go fiddle with the engine. I have a feeling this is something that will improve the starting on my Scotts... Q's: ---- ... Then continue past the same 1/4 inch drop of the piston as the single cyl engine. Im not quite clear in this procedure... It kinda sounds as if your telling me - with valve covers off and me spinning the crank Ill be able to determine TDC easier (makes sense - so far) ... Ill probably poke a screwdriver down the plug hole to approximate TDC... (or is the screwdriver a bad idea) i guess I could put my finger over the plug hole and feel for the compression stroke? Im wondering with the plugs out - will I be able to spin motor by hand ? how do the pros do this ? I assume its easier with 2 people - but I'm solo over here and Its likely ill be doing this alone... AND "the 1/4 drop of the piston" .... I need more details. Am I too assume the 1/4 drop ensures that both my valves are TRULY closed (on the power stroke) and therefore this is the best location to set the 4-6 clearances ? Mownie: ------- I was thinking about the TDC issue on a twin cylinder, obviously VERY important... Thanks for bringing that up as well !!! thanks again.

UCL is highly recommended for ALL classic cars especially when they are not often driven. 1- 5 tankfills a year means that petrol (USAterm = gasoline, gas) is in fact always old, somewhat deteriorating and collecting condensed water. Nowadays one should absolutely avoid bio-ethanolized petrol because some materials (metalparts, seals, rubbers; from petrolfill-entrance to and including exhaustpipes) oxidate and or desintegrate because of the ethanol and waterattraction. In Dieselengines UCL lubes the Dieselpump which nowadays is not lubed by the Dieselfuel anymore because Sulphur had to be eliminated from this fuel The Sulphur in the olddays Dieselfuel, lubricated the Dieselcompressionpump better than the modern Dieselfuel does. UCL protects/has benificial effects, also when fuel is not streaming or dried up (a thin protective oily layer of UCLoil stays on all surfaces before the burningstage, when the gasoline has evaporated after some days of stand-still) : Less rust in fuel tank Rubber gaslines don't dry out Petrol- and Dieselpumpparts (electric AND mechanical pumps benefit); membranes are lubed Carburettor is lubed (critical for copper and other non-ferroparts) Inletvalves benefit Cylindersurfaces are lightly lubed during firing and also already during the coldstart. UCL implies that only oil that combusts properly and burns fully, should be used. ONLY, ONLY AND ONLY 2-Stroke Oil does that. It will not carbodeposit on internal engineparts. Some people use engineoil, ATF or whatever. DON'T DO THAT, EVER. ONLY 2-Stroke oil is specially designed for nicely burning with gasoline and Diesel! Use cheap, the simplest undoped 2-Stroke oil, it may be not, half or fully sythesized. Use NOT the stuff disigned for modern 2-Stroke engines, as it possibly contains agressive dopes (Bad for aforementioned materials) . For years now, I use 1 part 2-stroke oil on 200 parts gasoline (ratio 1:200) . DIESELENGINES: 1 L for every 60 L of Diesel (ratio 1:60). Try to ride your fuel tank as empty as you dare before adding fuel, FIRST add the 2-Stroke oil so it mixes by and with the flow of fuel pumped Expect to use 50 liters of petrol? First add 250 ml (1/4th liter) 2-Stroke oil (= 2-T). This is a small beerglass on an average fill. Better use a dispenser with marks, though.... 40? 200 ml 30? 150 ml 60? 300 ml So every 1 L of gas, first add 5 milliliter of 2-T. Ratio is then 1:200. Sometimes I underestimate the needed gasoline to fill-up and allready added the 2-T. No problem, one time I calculated I had made a mixture of 1:100 (that is double the prescribed amount of 2-T) and experienced nothing in particular that half year later. Remember, 2-Stroke engines use 1:25 - 1:50 ratio which is 8-4 times 'fattier'. Mind you, Dieselmixture can and should be : 1L 2-T on a fill of 60L Diesel I provide ALL my none-catalyst diesel- and petrolcars with 2-T. From my Peugeot 201 of 1931 to my Citroën CX Diesel 1982 and gasoline-engined BX E from 1987.

You know montesa, at this time, even with all the EPA restrictions and 2 cycle engines, I don't think smaller 2 strokes will ever be totally banned from new production. There is still too much of an advantage and power to weight ratio to warrant not to produce them in certain type of equipment. There are a few companies left ie Bombardier/Lear Jet, that have enough financial capabilities to stay ahead of the R&D in takes to keep the larger displacement engines running more efficiently and for the GREEN WIENERS, cleaner. I think if Toro/LawnBoy could have somehow redirected the intake/combustion, added fuel injection, manadated fully synthetic oil in their engines only, or added a catalytic convertor, they could have meet EPA regs. Did they want to spend the extra money to develop, would it make the every so light and easy to manuever mower more heavy and cumbersome? Probably some of the biggest reasons they chose not to. I'll buy and use 2 strokes as a first option as long as I can. If I ever have to resort to a 4cycle trimmer or chain saw, then I give up my power tools. They only engine I will want to drain a crankcase on will be larger mowers, cars, trucks, marine, etc. If this man can carry it, then in needs to be a 2 strokin' high revvin' long livin', 2 STROKE!!!