Outdoor Power Equipment (Lawn Mowers, Snow Blowers, Chain Saws and more) Discussions

Happy holidays every one! ... bought the toro 1028 OXE back in October, right after the very first early snow storm. Was not able to try it in snow... I added the startron stabilizer And filled up the tank with 93 octane. I tested the new baby, showed off without spinning augers... But now it's a long time unused. My question is: is it okay for the fuel to sit in the carb for such a long time? Thanks!

JoelKlein wrote:
The engine's knock (ping) sensor will monitor how the engine is running, yes. The ECU may try to advance the ignition timing, to produce more power. Higher octane gas will allow the timing to be advanced more, without knocking/pinging. If you run lower octane gas, the ECU will retard the timing to avoid knocking. You might see less power and reduced mileage. I had a car that recommended premium. When premium got to a level that I thought was unreasonable (~$1.80, as I recall. Clearly this was a number of years ago ), I switched back to regular. The engine automatically adjusted, and I could feel that it had a bit less pep, and my mileage dropped a little. But it was still cheaper.

But the engine cannot, so far as I know, change the compression ratio on the fly. The only ways to do that that I can think of would be to change the head, pistons, or maybe the crankshaft. But I don't think the compression ratio can change while you're using it.

There are only a few ways to increase compression ratios in an internal combustion engine.  One decrease the size of the combustion chamber by
1. either using a flat top or dome piston (in place of a dished piston), and or using a set of heads with a smaller combustion chamber.
2 using forced induction such as a turbo or supercharger.

Injectors, air cleaners and headers will do nothing to increase compression ratios.

Higher octane fuels can help hp when the if the  ecu can advance the timing by helping the engine not have pre-ignition or ping thus increasing hp a bit.

Most engines will not see any difference in performance or gas milage using high octane fuel.  In fact a low compression engine (8:1)will probably run worse on high octane gas.

So all I need is a forlmula to calculate the added engine HP and how often the engine Actuly take advantage of it... Otherwise I'm like writing a 5 line paragraph on a big 11x17 sheet! But what about the detergent factor? Any ideas ?

I use the 91 octane in all my small engines because the 87 and 89 here has 10% ethenal in it and the dealer told me that stuff goes bad faster than the regular gas without it. The 91 does not have ethenal in it as its for off road, collector cars, and stuff like that.

How does forced induction change an engine's compression ratio?  It doesn't impact the bore or stroke of the engine.

Forced induction basically compresses the air before it enters the cylinder.  Basically, you get more volume of air in the same space.

So back to snow blowers. What's the issue with 87 octane? What does it mean " major brand" gas ?

Just to make sure we differentiate.....  A car may or may not have computer adjusted timing, to maximize performance to the octane rating.  Now I seriously doubt my SB has a computer chip in it ... correct me if I'm wrong... so using the recommended octane is highly recommended.......

I agree 100%. But the Manuel states it needs gas from a GOOD gas station. What in world does it mean?

I use 87 in my 4 stroke ope and 91 in my 2 strokes because the Echo dealer told me to do it 10 years ago when I bought my blower and string trimmer. This was about the time the fuel additive package went from MTBE to alcohol. I haven't had a problem but I may not have experienced any with regular so who knows. The difference in $ for the amount of 2 stroke i use is negligible. I also own an FJ cruiser (2007) which suggested premium grade in the owners manual. I can report that when i tried 87 the fuel mileage dropped by about 2mpg. When I went back to 91 the mileage went back up. Marc