Am I wasting my time and money

[Larry M]

Are you saying you have had this boat out and it would only run 27MPH? Something is wrong, you must not have a prop any way close to the right size. My Dad had a mark 40 back in the 50's on a Feathercraft which was a lot bigger than mine and it would run 35 MPH and I know your boat would be a lot faster that. My Uncle had the same motor on a Yellow Jacket boat and it was faster than Dad's.

[MadProps]

Larry M show us dont tell us, show us any mark 55 service motor doing 55mph

lots of MK55's out there, if it is possible surely there is a video of someone no?

[Larry M]

I said a 40ci would run 35 on my Dads FeatherCraft and my smaller FeatherCraft with a 44ci motor and a Merc racing unit would run almost 60. I have 40CI hydro that we raced that would run 80MPH. If you don't believe that just ask around about Kevin McAfee.

[Special K]

My little red 8 foot boat that I pictured does 27 with an 18hp evinrude. I never thought a mark55 would ever do much over 40 but thought since it came with the boat that someone knew different. I’m learning pretty quickly that I have a cool looking fishing boat.😁

[Super Splinter]

What I would do is take it out and run it and see what the speed is, right now it is just a guess. I had a FeatherCraft aluminum runabout with a Merc racing unit and it would run almost 60MPH this was with a 44 merc with stacks and no porting. Another guy had a aluminum boat with a 44 and a club foot and it would run almost the same speed.

[Bob Rusnak]

Special K, I would not give up on it. Looks like a fun project as long as no one complains about the open exhaust. Take it one step at a time and work with it. As you try different things, height, kick out, weight distribution and props you may be surprised. I fooled around with things like this in the Long Island Sound. lots of fun and got to learn a lot by doing this. Those MK 55' are fun.

[MadProps]

specialK
check your PMs for several videos of MK 55 40hp service motors on hydros and a larger MK58 45 hp on a GW invader clone like your red boat

ofcourse they are fun , but this is realistic speed tests videos, no where near 55mph.

you decide friend

[Special K]

I clearly see from mad props video that this motor will probably not do much for me. If his video is a true test of this motor as it sure looks to be, other than being careful in any boat in general it doesn’t appear the speed is very impressive even to a weekend funseeker let alone a real racer. As for the m-phone exhaust noise I do have the stock exhaust plate and cover if I need to tone it down but the people around here are pretty used to constant jet ski noise and plenty of loud speed boats pass this stretch all the time. Plus I know the nature cop 😁😁 that would most likely show up to a complaint. But in all honesty I’m going to think long and hard about continuing this project or just going another route on a motor.

[Special K]

My original post was never asking about what you have done or your grandpa did. It was about what I could expect from the motor I have and that motor alone. I’m aware I can buy better gear cases, or other motors, hell I can buy an 18 foot 454 big block boat for the price of a racing set up for this little boat. Seems you guys like to argue facts but facts can’t be argued. I’m pretty convinced that my present setup will not move me very fast. I appreciate all the advise and some has been helpful in the direction that I probably have no grounds to be messing with this boat in the sense that the motor I have will not be enough for a smile and spending money on something that will seem impressive will probably just jeopardize my safety because I’m not a hydro racer.

[Larry M]

I was the one wasting my time. I tried to give you a little background on what to expect but that was a mistake on my part, have a good day I'm done.

[Dennis Crews]

Larry, trust me, there are plenty of us who will take any boat racing advice from you anytime.

[mark40h]

Larry it seems like there are alot of know it alls on this site.They don't need any help from an old pro like you that has never been around a race boat. LOL Art

[Special K]

I’m not really sure where this thread went from wanting expected speed info for a stock mark55 to not taking racing advice from an old pro. My original post actually said I’m not a racer. I’m sure Larry has very valuable racing advice if I was an inspiring racer asking for info on my racing motor. When you ask a somewhat simple question of speed from a stock production motor you would expect pretty close estimates from anyone. When you get answers from 30-55 then I guess you have to start forming an opinion. Madprops has an actual video showing this motor on a hydro compared to a hydro going 46mph with a race motor. The stock 55 is no where near 46 let alone ever going to go 55. Seeing is believing.

[foreveryoung]

Do you know Rick Wagner who lives in Mentor? Raced for years, in fact his son still races. He knows just about anything about boats & motors.

[Special K]

Looks like I may be able to find him. Looks like he goes by wagnerracing on the net and possibly on Facebook. (I don’t do Facebook)