Re: How fast should a 305 228 hp go?
Just bought a 1979 18 foot Thunderbird Formula. with a mercruiser 305 228 hp. Starter was out when I got it. Put starter on - RUNS great (so far). When we purchased it the guy said it ran 45-50 with 4-5 people in it. Speedo says it is going 37 full throttle with 4 people and NO COOLERS OR EQUIPTMENT. Thought maybe a tune up may help??? Any thoughts on how fast it should go or what may help give it a little more power. Seems kind of slow for a motor of that size. Our old boat was 135 hp and went 35.
your 7 mph off from the past owners lowest observation when he owened the boat..I dont think your off too much.
Water conditions and the way you trim the boat etc. could eat up them mph in a heart beat. Give her a tune up and play with your trim when your out. I would not freak out your speeds sound real close.
Its hard to say how fast you boat should go, you could take 2 exact boats set them up the same and get big differences between the speeds. As I said before water conditions and trim are a big factor. My boat can differ 5+ mph in water conditions from glass to a minor chop. same with trimming too low or high.
I have bought a few boats over the years and have noticed the previous owners sometimes seem to stretch things a little when trying to make a sale intentional or not.
To get 50 out of your boat seems pushing it to me. Maybe 3:00 in the morning running on a silky smooth lake with 2 naked 100lb adults and an 1/8 tank of fuel + a gallon of cool-aid and a bb&j samich
...........it works for me
Denny
