vacuum

[rdh]

will the highlift blades give you more vacuum if you take spacers
off so they are closer to the top of the deck ?

what happens if you change blade hight this way (hi-low) ?

would this have any thing to do with blow out ?

what give more vacuum?

[KD'sLawns]

It will cause more problems than it will be worth. Manufacturers set the blade heights for optimum performance, that's why they do all the testing and experimenting.
If you move your blade closer to the deck, all of your cutting heights will be totally different. Also, the un-cut grass will be so high that it blocks clippings from reaching you discharge chute thus, not allowing for very good bagging if any at all. If you mow tall moist grass there will not be enough space between the blade and the deck to allow for clippings to fall back through causing build-up on the deck that the blades will have to plow through. the build-up will contribute to no vacuum from your high-lift blades, and dull and worn blades quickly.

[awm]

i always side discharge so my experience is there.
high lifts will give more vac than standard.for me a set of high lifts on top of mulchers created enough vac to suck a cast iron meter plate into the blades. the only thin about a lot of vac is the air is got to go somewhere. i assume this may be why some have blow back on doubles.later now

[Stonewall]

On my old 48" Scag walkbehind with a Trac Vac, I would do what you suggest and put the blade above the spacers. If you're cleaning up leaves/straw and not cutting grass, it does the job. Reduced blowout tremendously.