stumped NO TOPEND POWER

[boston13]

I have a 84 johnson 40 hp On a 1967 13,3 boston whaler. When I take it out it runs good but just seems like i should be a little faster. it Maxes out at 3400
rpms. I beleave it should be 4500 to 5000. why is it not reaching max proformance. 150 lb of compession, two brand new ignition coils and plugs. carbs rebuilt. I am an automotive mechanic at my witts end. PLEASE HELP!!!!!!!!!

 

[tashasdaddy]

Re: stumped NO TOPEND POWER

you may possibly need a linc n sinc. did you check spark? are you sure there is not water in the foam of the boat? also may not be propped correctly. that motor should be turning atleast 5000, and as high as 5600.

 

[boston13]

Re: stumped NO TOPEND POWER

linc and sinc? propwas just repitched ths past weekend from a 15 to a 14. water in the foam has always been in the back of my mind. how do i know. if there is water in it?

 

[tx1961whaler]

Re: stumped NO TOPEND POWER

Water in Whaler hull FAQ:
http://continuouswave.com/whaler/reference/FAQ/#Q3

A subject of sometimes intense debate is whether or not Whaler foam absorbs water at all.

It certainly is possible for the skin to delaminate from the foam after damage and allow water to be trapped in the hull.

 

[kenmyfam]

Re: stumped NO TOPEND POWER

Weighing the boat will tell you immediately as long as you know the weight of your individual items that are being weighed at the same time. I checked mine out a few years ago. Take out everything that is not bolted to the outfit, find the weight of your motor, if you know the weight of your trailer then great, if you do not then weigh the boat, motor and trailer together (take into account the amount of fuel if you have a built in tank) then put the boat in the water and go weigh the trailer (if you do not know the weight already) do the math and see if you are a few hundred pounds heavy or not.
\
Good Luck and let us all know.

 

[boston13]

Re: stumped NO TOPEND POWER

i dont beleave it has water in it but it is posible it sits in the water nice. I think it is in the motor? the boston whaler standard weight is 320lbs. Thanks guys. Ill let you know.

 

[tashasdaddy]

Re: stumped NO TOPEND POWER

linc n sinc, is a step by step procedure, adjusting the spark and the carboration, so that they work in sequence with each other. it is a little different for each motor, and is cover in the Johnson service manual for your specific motor.

 

[boston13]

Re: stumped NO TOPEND POWER

thank thats what i thought it was. i read about it in my manual. i am a little confused is there points and condenser on older motors or not at all. is it all electronic ignition with a crank sensor/or pickup. i checked timimg and it was 19 degrees at WOT. I think it is just out of sink and i am over looking somthing. I am going to read over the procedure again and see if i missed something.

 

[hadaveha]

Re: stumped NO TOPEND POWER

check into that weight issue i have a 1964 13 ft whaler i finally weighed it i was dragging around abour 600 lbs

 

[boston13]

Re: stumped NO TOPEND POWER

were you having power problems? my thing is the motor should windup to max rpm. if it weighed 600 lbs it would just take longer to plan out. or it would stay at max rpm but not go anywhere. it is just not reaching max power.

 

[kenmyfam]

Re: stumped NO TOPEND POWER

were you having power problems? my thing is the motor should windup to max rpm. if it weighed 600 lbs it would just take longer to plan out. or it would stay at max rpm but not go anywhere. it is just not reaching max power.

Disagree with that one. If it is pushing an excessive amount of weight it will not reach max RPM.