None
IT will spin at the same speed & just use more petrol
Now if you wait till you can not see the dog above the grass it might let you cut the jungle faster but the limiting factor is usually the volume capacity of the deck to handle & discharge clippings.
If you live on the side of a big hill then it will go up the hill a bit quicker
Most modern mowers are grossly overpowered because they get bought by males with V8 envy so a bigger engine must be better .
One of the local makes ended up putting 24 Hp engines into the same mower that used to have 8Hp engine.
The extra power did nothing other than snap belts .
OTOH I have replaced big engines with smaller ones and not a single customer noticed any difference apart from the one with the Time Master who found that the deck belts lasted longer & he used 1 jerry can less fuel a week .
This was nt intentional it was just what engines my wholesalers kept in stock so they were cheaper .
I bought my LT1000 new in 2005 for $900. After a decade I had tough time cranking it, did the valve adjustment thing, would keep the battery on a tender even though it tested fine under load. Then one day it apparently got an oil leak and the oil leaked out and ruined the engine. I decided to buy a slightly upgraded engine through an online dealer (even had an oil filter !!!) which claimed a couple more hp, but I didn't notice any difference.
The engine bolted right in, and this engine cranks readily, don't need to monkey with the valves or use a battery tender anymore. So I was a happy customer.
#5
StarTech
Whoa here Bert I beg to differ here from personal experience on the same type of upgrade.
Here I have a 42" Yard Machines mower that had a 16.5 hp Intek that I upgrade to 21 hp Intek.
Before the upgrade the mower struggled to cut the full deck width if the grass to removed was 2 inches and that was in second forward gear speed. Now with the larger engine I cut nearly 4 inches off at full forward speed. I also cut over 12 inches off if I slow down, travel at half speed and cut half the deck width so the deck has time to clear clippings. Now course I had to upgrade the deck drive belt from a 1/2 to 5/8 belt as I keep burning up the belts.
But yes you be operating at the same RPM but you have a lot more torque available. The 16.5 is a 31 cu in and the 21 is a 33 cu in setup. Also the 16.5 most likely has a restrictor plate installed as they are the CI as the 19 hp.
#6
Grizzly Adam
We will see how I get along then. I am picking up another LT1000 tomorrow, this one with a 20hp intek and 20” rear tires. I am hoping to see a significant difference in cut quality and ability to get up the back ditch.
#7
Cusser
Remember: cut quality is pretty dependent on blade condition.