I've been using a 28 cube briggs. Had a 17 twin in the 58Z when it was still the 580 CPR. Its faster with the single. The new one has a 28 cube briggs also.
Yep, your sled gets around the track pretty darn fast with that 14.5 OHV Briggs -(with you on it)....but, you also are also probably only 110lbs soaking wet at best. I have 150lbs on you, that does make a considerable difference out there. Especially with Stock engines.
Lester is right 540 all the way its hard to find at least around my area unless you wana buy brand new one.
There are no new ones...Kawasaki Discontinued the 540v many years ago. There are used ones out there, actually not that hard to find...look for a John Deere 180 or 185 or bigger.....you can buy the whole mower with engine for much less than what people are trying to sell the engines for. I just bought one for $100.00 with a blown hydro, and another for $165.00 Both came from PA and when I was up there picking them up, I found four more that had 540's. (On PA Craig List)
People are asking $400.00 to $650.00 on Ebay..........like I said..."Asking". Don't believe they are getting it.
Now....food for thought...Now...I will only buy them if I can see them running. The last 3 I bought, were just a raw engine, seller(s) claimed they ran.......they did not.....total loss of a few hundred hard earned bucks.