Suggestions please

[Soundslikefun]

1964 16' MFG Westfield with 1964 Mercury 65 HP. Took it out today for the first time and while it ran great, I was expecting a bit more speed. Currently the prop is 3 blade with a 15 pitch. Would I notice a difference changing props on something this old, or am I probably seeing all it has to offer?

 

[steelespike]

Re: Suggestions please

We need a lot more details. Need your present prop size, max rpm and speed.A tinytach is about $40 and easy to install.A gps is best for speed.You could notice a difference with a prop change.
Check your setup.Your antivent(cavitation)plate just above the prop should be about even or a little above the bottom of the boat.You have an older style gearcase so your height may vary.The idea is to have as little drag as possible.
Be sure the motor is in excellent tune with carbs and linkage adjusted carefully
Is the prop in excellent shape?
The hull is probably not the fastest design in the world probably more on the comfortable side than fast.

 

[Soundslikefun]

Re: Suggestions please

Current prop is 77342A45P15. Don't know max rpm or speed yet, I guess I'll work on that info. Motor height seems fine and it's running great. Just had carbs done.

Had it out today with a GPS. A mighty 10mph is all it had in it. It seems it just doesn't have anything more, but when it's in the driveway with no load, it'll rev much higher.

Same boat last year with a 75hp Evinrude from 1960 that had no compression would take me to 30mph all day long.

 

[steelespike]

Re: Suggestions please

Ok, you have issues other than prop.Could be as simple as a plug wire off or bad plug. Performace in the driveway means nothing.Motor has a belt driven distributor/magneto.any number of things could be wrong.Some of these have a rectifier and solidstate ignition.Any trouble shooting should be done following a repair manual.some of these old Merc. setups distributor parts are hard to find and expensive.

 

[Soundslikefun]

Re: Suggestions please

Ok, you have issues other than prop.Could be as simple as a plug wire off or bad plug. Performace in the driveway means nothing.Motor has a belt driven distributor/magneto.any number of things could be wrong.Some of these have a rectifier and solidstate ignition.Any trouble shooting should be done following a repair manual.some of these old Merc. setups distributor parts are hard to find and expensive.

You think it's likely electrical rather than a fuel issue? Even though I just had the carbs and fuel punp rebuilt I have no way of knowing it was done right other than good performance, and I do not have that. I'll look into electrical problems.

 

[Soundslikefun]

Re: Suggestions please

So after some more playing around with things I noticed when they mounted this motor on my boat and put in new cables, it's setup so the throttle never really opens up. I tweaked it and now it will, but the idle is too high. It did reach 25mph today, which is pretty good compared to the 10mph Sunday. Somehow I need to adjust the distance the cable travels for a given amount of lever motion. The cable needs to move about 3/4"-1" more than it currently does.

 

[junior1113]

Re: Suggestions please

you might want to ask that question in the mercury iboat forum. they know more about mercury throttle adjustments

 

[cougar1985]

Re: Suggestions please

do not rev your motor when its not under load or sooner or later you will have a runaway and then you will be asking how to rebuild it !had one of those motors it was a good motor.