This may sound silly but is there any reason to go with a 5.5 versus a seven if they are the same price? Both are Honda but the seven has a common pump and the 5.5 an AR.
I’ve noticed a lot of downstream products are marketed for up to 5.5 And more use an adjustable X jet.
I already have a 225 gallon buffer tank that I got a great deal on to use either way.
It really comes down to what engine you’re using. If you’re using a smaller engine to power a larger pump, you’ll get less psi overall. If all you do is house washes, no prob. But if you’re doing flat work, then you need to make sure you have the psi to do it. And depending on the Honda engine, you might not have the psi to do it.
I really don’t see it possible to pull start a v-twin motor, maybe a kick start.
BTW be sure to bring your starter battery in after the season is over, I managed to kill mine by leaving it in the trailer for three months over the winter. They typically last three years, then start giving you fits with weird symptoms.
I used to pull start mine at least one a month. Had to find out if it was going to break. Better to break it at the shop than in the field when the battery decides to croak
Trouble is, I could set it ablaze & whack it with a sledgehammer at the house. This stuff will never crap out if it ain’t ‘party time’. Hopefully your luck is just a lot better than mine haha.