55.1 mph with 30 hp mercury

[tyst67]

Well my motor is the same as the 59ci except 1 cylinder is chopped off and with a little timing advance and a few other things, these motors will scream! I believe you that a bone stock 3 cylinder will go 53 cause there are 5 of them in our boat club and they are fast! As for distance vs time, I'm gonna say if the other 2 guys don't believe me that's their problem! A GPS is accurate enough for me and I don't thing a GPS is gonna be off anymore than a few mph one way or the other! I didn't join this forum to be called a lier and If you don't believe me than oh well! I just tried my GPS and its the exact same as the speedometer on my truck! So I guess the next time I get caught for speed I will tell the police officer your theory and tell him I was actually doing 20 mph slower! BS !

[phillnjack]

Now before you get carried away with your 60hp merc doing 53 mph with a 20 inch chopper, rememeber what the boat is and what you can and cannot run in e900 class !!!!
no jack plates, no special race boats,must be stock just like in the showrooms,no special fuels and all the seats like it has in showroom as well.
if you put your 59ci merc on a phantom youl be lucky to get 40mph , the boats are totaly different to lake boats,these phantoms run offshore and have been winning world titles since the early 1970's.

Now your getting 53mph with a 60hp, yet are 6 miles an hour slower than a 2 cylinder 30hp on a sheet of plywood knocked up in the woods then given a epoxy coat to make it go super fast .

seems like a good few records will go as soon as you all take these boats to a record run place.
Get a local sherrif of the river to check your speeds,if he ratifies them im sure youl get sponsorship from mercs to
run the nationals.

[phillnjack]

Just measure a distance and time it, you need a nice big mile, thats 1760 yards,not a theoretical mile.
and to run a record you need to do the kilometre as a minimum.

I think the boat in the video is hitting around 38 to 42 miles per hour,definitely not 50, that is my honest opinion.
ive had 50mph boats and also a lot that were and are slower.
i wish you were in the uk as i wouldnt hesitate to come and race against you , and mine aint a 50mph boat yet.

[tyst67]

What does your gps read in mph?

[tyst67]

Ok so I just went out and measured out 1000m with my works 100meter tape and then ran my boat! I went up stream to get a run for it and hit the start line at maximum speed! I started the timer at the start and then stopped the timer at the 1000m line! My timer only measured in whole seconds not milaseconds. So it can only be so accurate! The time was 38 seconds with the current and then I ran the distance again going upstream, again getting a run for it and hitting the line at wot, my time was 41 seconds. So this figures out that my down river speed was 94.7 km per hour or 58.8 mph and my up stream was 87.8 km per hour or 54.6 mph. So I added the upstream speed and the downstream speed together and divided by 2 to get my average speed and it was 91.3 km per hour and 56.7 mph.

[zul8tr]

Well looks like that is a fair check with his numbers and the reported speeds are being attained. I still would like to know what rpms you are running to get those speeds.

[tyst67]

And I am gonna be fully honest, the motor is a 30 but its actually a detuned 40, being restricted with a small Venturi and smaller reed holes! So you put the 40 parts on and add some timing and these motors scream! And to be honest I had issues hooking up a tach so I am basically using the prop calc to estimate my rpms! The hard fact is even if it is hard to believe, my motor is that fast and right now I can even beat a few 59 ci mercurys around here!

[Riverrat001]

Now before you get carried away with your 60hp merc doing 53 mph with a 20 inch chopper, rememeber what the boat is and what you can and cannot run in e900 class !!!!
no jack plates, no special race boats,must be stock just like in the showrooms,no special fuels and all the seats like it has in showroom as well.
if you put your 59ci merc on a phantom youl be lucky to get 40mph , the boats are totaly different to lake boats,these phantoms run offshore and have been winning world titles since the early 1970's.

Now your getting 53mph with a 60hp, yet are 6 miles an hour slower than a 2 cylinder 30hp on a sheet of plywood knocked up in the woods then given a epoxy coat to make it go super fast .

seems like a good few records will go as soon as you all take these boats to a record run place.
Get a local sherrif of the river to check your speeds,if he ratifies them im sure youl get sponsorship from mercs to
run the nationals.

The motor was a 59ci block but was detuned to a 40. It was on a 15x48 aluminum semi vee boat but did have a 5" jack plate. I'd love to race you now. It has a little modification done and will break 70mph on a 13' Allison

[tyst67]

Nice man!! I would love to have one of the 59 ci cause they are just awesome! I have just about everything my wallet can afford done to mine lol I just pick away at it and just try different things with it and I seem to have alright success! The 55 hp sea pro's in our bout club could be a lot faster than they re but they don't realize how awesome those motors are! I would love to share some of the things I have done to my motor ! Maybe we can share secrets lol

[LittleCharger]

Well done!

The tiny tach should work, sometimes on the two cylinders you have to wrap the sensor wire around both spark plug wires, this is what I have to do on the sst45 motors. Contrary to the previous comments we find them to be accurate and use them on everything from chainsaws, snowmobiles to hydros in testing as a secondary source.