engine size decision

[tim482]

Hi,this is my 1st post.Bought a 20 ft. bass buggy pontoon boat last fall,it came with a 40hp Johnson 2 stroke,the lake 7 miles from my home that we camp and fish at is a no wake lake,do you think this engine would be good puttin around for hours at a time at idle or should i be lookin for something like a 9.9 to replace it with? Also i should mention that this 40hp is going to need some attention if i decide to use it,it stalls a lot at idle.I have kitted the carbs and replaced the water pump which helped a lot ,but it still has some low rpm issues.Thanks for any help,i enjoy reading the topics.....Tim

 

[steelespike]

Re: engine size decision

If it is a no wake lake a 9.9 or 15 might be happier.If your motor has a low speed
mixture adjust try to get that set.A bad diaphram on the fuel pump could cause
idle problems.Could leak fuel into the crankcase as well as not pump enough at slow speeds.

 

[EGlideRider]

Re: engine size decision

I agree with Steel. I would replace the fuel pump and then if you still have problems, go with a smaller motor.

 

[tim482]

Re: engine size decision

This engine has the vro pump disabled,the oil is mixed manually,what would be a good way to test for adequate pressure at the carbs?

 

[Silvertip]

Re: engine size decision

If the engine runs fine at faster speeds the fuel pump is not the problem. Fuel pressure requirements are the least at idle -- maximum pressure is required at higher speeds.

 

[EGlideRider]

Re: engine size decision

I don't know how to test the pressure, but if the engine is more than seven or eight years old, I would change it anyway.

I had a mid-80's 140hp Evinrude once with the same symptoms as yours. After lots of needless work, I finally changed the fuel pump and solved the problem. The diaphram was stretched and couldn't deliver enough pressure at idle. Although I never noticed any better performance at high speeds, I'm sure it must have improved.

Good luck and report back your findings.

 

[tim482]

Re: engine size decision

The weather in Iowa is not suitible to test at lake speeds yet.Most of the tuning i have done has been with muffs,i have never had this boat on the water yet. I should also mention that when i bought this boat it had just been redecked and new furniture added. The downside is the guy took all the gauges and tossed them when he added the new transit,So now it sits with a nest of wires hanging. The ign. switch,steering wheel,and shifter are all hooked up and working properly,but the hanging wires is something i am going to figure out where to start. I have really appreciated all the good info on this site,i have been an auto mechanic most of my life, but am eager to learn all i can about this boat.The boat came with a nice trailer ,new deck and furniture,cover,and a whole bunch of accessories for 2500.00 so i think i can throw a little money at it and still be happy......Thanks Tim

 

[steelespike]

Re: engine size decision

If you go to brokeboats.com there is a wire color code chart as well as lots of other
sercice oriented info.

 

[tashasdaddy]

Re: engine size decision

all the guages are not necessaries. to me they are a PITA, the break, malfunction, etc. make you worry something is wrong.

What year or model # is the 40 hp, you will get better advice. 40's range from th3 1960's thru today.

 

[Mark_VTfisherman]

Re: engine size decision

This engine has the vro pump disabled,the oil is mixed manually,what would be a good way to test for adequate pressure at the carbs?

Pressure is less important than volume at idle speeds- all you really need to have is enough volume to keep the bowls filled.

Having said that, I would sell out that 40hp. That is a nice motor for someone who can use it. A no-wake lake like what you mention would be your home waters would best use a smaller, more economical motor. Plus, to get any speed at all, you can run it opened up a little which would help keep the plugs clean.

I would sell the 40hp and buy myself a 15hp - maybe even a newer 4-stroke. Then you can count the savings (and quietness) every time you run it.

 

[tim482]

Re: engine size decision

Thanks for all of the good advice,not sure what this motor would be worth ,but i might try to get it running correctly 1st so it would be easier to sell or trade... TJ40ELESR is the model .............thanks Tim

 

[Gary H NC]

Re: engine size decision

That should be a 1990 year model....

 

[JRJ]

Re: engine size decision

I got rid of a 2-stroke, replaced it with a 4-stroke, and never looked back. Just my 2-cents