i've noticed some people leave their riding mowers/lawn tactors at full throttle all the time. even when starting. is this hard on an engine?
also is it good to engage and dis-engage the mower deck at full throttle or idle or half throttle?
does it even matter?
These questions have been asked, and addressed, several times recently. I'm like you, I don't like the idea of starting an engine at full throttle, or even half, for that matter.
From the owner's manual for my '02 J-D GT235:
1-depress brake pedal
2-If engine is warm, leave throttle lever in "slow" position
3-Push and hold choke leverNote:choking may not be necessary when starting warm engine
4-turn key to RUN, check indicator lights
5-Turn key to START, blah, blah...
6-As soon as engine starts, release key.....release choke....put throttle lever in appropriate position
This is for an 18hp B&S engine.
From the owners manual for my '08 X748:
1-open fuel shutoff
2-depress brake pedal
3-Push throttle lever up to between 1/2 and fast position
4-turn key,5-check indicators, wait for preheater (diesel)
for a Yanmar diesel
From what others said, the V-twin gas engines is much the same. My dealer started mine up at about 2/3 throttle, and shut it off the same way.
My thoughts are, if the engine oil pump sufficiently lubes the engine when it is running at idle, then it should also provide enough oil at start-up at idle. If the engine is used fairly frequently, like every other day, or thereabouts, there should be enough residual oil in the galleys and bearing surfaces to provide an immediate supply when the engine starts up, regardless of engine speed. But if the engine has sat unused for an extended period, more of this residual oil may have drained due to gravity. Nevertheless, if the oil pump is in good condition and clearances are nominal (close to normal), then oil will start to move as soon as the engine is cranking.
So maybe it doesn't matter either way. I know that I won't start mine at full, or even half throttle, I usually crack it just a bit above idle.
As far as engaging the deck, I start the deck at full throttle, which is also what the manual recommends. The HST in my 748 has internal clutches , but my GT235 is the electric variety, and it at least needs a good bit of rpm's so it doesn't stall the engine