screeming prop

[yoggii]

I just got a 14 ft. jon boat with a 35 merc,it has a 10.5 pitch prop and the motor is screeming..thinking about a 13 pitch,is that enough??

 

[BonairII]

Re: screeming prop

You have to hook up a tach to your motor to prop it correctly. It's not something you can do by ear.

Underprop and possibly blow your motor

Overprop and you'll 'lug' your motor(decreasing it's life dramatically)

 

[steelespike]

Re: screeming prop

Tinytach is easy to install and can be hand held or permanent.
What year motor and 2 stroke or 4 stroke?

 

[pootnic]

Re: screeming prop

A narrow/wide,heavy/light;14' jon boat?
Flat bottom,console or tiller steer ?
35hp seems to be a big motor for that size boat,especially if it's a narrow one but anyways....
A tach is the only real way of knowing for sure(like said above) but I guess it would be at least a 13 pitch,probably even bigger;15ish.

 

[yoggii]

Re: screeming prop

its a 1984 35 merc.and yes boat is rated for a 25 hp,but it was on it when i got it.14 ft polarcraft jon boat.i dont have a tac but i,ve had a lot of boats and i can tell it jumps out of the hole and its screaming.im going to try a 15 pitch i think next week.the 14 ft boat handles the 35 hp great,its fairly wide.Just rebuilt carb today ,took it to the lake and runs perfect for about a minute and then it quits unless you pump the ball...fuel pump???

 

[steelespike]

Re: screeming prop

Sure sounds like a fuel pump.could be sucking air somewhere,maybe a plugged filter.
You might want to post it in the Merc forum might be they may have some specific info.

 

[pootnic]

Re: screeming prop

Could be fuel pump or air leak(fittings) as mentioned...also the ball itself can be bad.
Like also mentioned above those little tachs aren't that expensive and can be a big help with a few different problems.
I never had one for years but about the last 7 years I've been using the tinytach(there are other brands as well).

 

[yoggii]

Re: screeming prop

update!! Put new diaphram in fuel pump,took it to the lake and run for about 20 min.,ran great,but I got to get that 10 pich prop off.thanks for the help!!