1962 lark

[jason176]

I got my boat running and it runs quite well, I have decarbed it and am running fresh gas in it as well. However after about an hour on the water the motor doesn't want to run at higher rpms. It just kind of starts to falter and will die unless I back off of the throttle, it seems like it won't do it in neutral just in drive. Also, my boat won't plane very well, got to have somebody get in front of boat to get near planed but never actually does. I looked at my motor and it appears as though my anti-cavitation plate is about 2 inches below the bottom of the boat, I believe it needs to be closer to the bottom of the boat but is this what is causing this. I also cannot tilt the motor down anymore. I think that my motor may be a bit heavy for the boat or I need a counterweight as the back of the boat appears to be sitting kind of low in the water. Sorry for my rambling, I don't know anybody who is up to par on boating like those who frequent these forums. Anyways, thanks in advance.

 

[CATransplant]

Re: 1962 lark

The problem with it running at high rpm's could be a bad vent in the tank, perhaps. Or it could be marginal in the cooling department. I'd check the second thing first.<br /><br />If you haven't replaced the impeller yet, it's time to do that. Also, check the thermostat on that engine and see that it's working properly.<br /><br />You don't want to lose this fine old engine for lack of maintenance.<br /><br />If you describe the boat you have your Lark on, we might be able to help you with this.

 

[rennen]

Re: 1962 lark

I am having the same problem with my 63 Lark. Mine was three inches too low. So we built a riser and the boat is a bit faster but still wont plane unless I am by myself. <br /><br />So in short Yes it will help to raise your motor but some of the more familiar people will probably suggest that your motor has some sort of problem.<br /><br />Just for your info. they have told me to check the spark to both cylinders, vaccum cutoff switch, carb and fuel system. Maybe this will work for you as well?<br /><br />Cheers,<br />Sal

 

[surf1960]

Re: 1962 lark

I don't know where or who you might ask, but it is easy, 10 min, to remove the prop. Check to see the diameter and the pitch. Old motors have probably been on a number of different boats and you might get better performance with a different prop.

 

[jason176]

Re: 1962 lark

Is there a way to check the impeller or do I have to just replace it. There is water coming out of the water outlet and I have the temperature sensor hooked up and haven't had the dummy light turn on. Also, how would the cooling system affect the motor in this way, not to question your knowledge just being curious. The boat is a 14' fiberglass v-hull, unfortunately I am unsure of the weight. Also, I tried to identify the pitch of the prop but I can't find a number stamped on it, gonna have to look harder. When I give it throttle with a buddy in the boat it actually kind of just revs and hardly moves but when I send my buddy to the from of the boat she starts to move.I actually got a really good deal on the boat,motor,and trailer and have taken it out a couple of times already, but I find it a bit small for my liking so I am actually planning on selling it and buying a pontoon, I just want it to be in good running order before I sell it (karma), I really like that old motor though, runs smooth and looks really cool.

 

[lark2004]

Re: 1962 lark

best just to replace the impeller. They are cheap. An engine rebuild is not. They need replacing every couple of season any way, so don't worry about trying to save the old one.

 

[CATransplant]

Re: 1962 lark

" When I give it throttle with a buddy in the boat it actually kind of just revs and hardly moves but when I send my buddy to the from of the boat she starts to move."<br /><br />That sounds like a bad hub in the prop that's allowing the prop hub to spin under load. That would also explain your inability to plane.<br /><br />Take the spinner off the back of the prop shaft and mark the prop across one side with a sharpie or other waterproof marker. Put the spinner back on and run the boat at WOT. Check the mark. If it doesn't line up any longer, it's a bad hub. Although it can be repaired, you may be better off with a new prop or a good used one.<br /><br />That it seems to slip with an extra load in the boat is the indication here. It's probably slipping all the time at WOT.