WOT Hesitation

[manykids]

Have a '02 Johnson, 2 cycle, 90 HP. At WOT it sputters. It seems to at lower RPM, but not as noticably. We have added heat to clear any moisture. The tank is venting. The manual says to have it serviced.

We guess either carb. adjustment or choke problems.

Does anyone have a suggestion?

Can anyone clue me in on how to make adjustments?

 

[manykids]

Re: WOT Hesitation

Come on guys. I am posting this for my Dad. I told him how much helpful information is posted on iboats. Don't let him down 8)

 

[manykids]

Re: WOT Hesitation

OK guys / gals....I talked to two service centers. One said the oil pump may be going out and therefore the engine was shutting down momentarily to keep it from being fried. The other suggested going to WOT and checking the primer bulb. If it is soft, an air leak is indicated and the fuel line needs to be replaced.

Now does anyone some help?????

 

[Walker]

Re: WOT Hesitation

The oil pump should give an alarm if its going out.
The bulb will be relatively soft at WOT. That's normal. You can try pumping the bulb and see if it makes any difference while its sputtering.
But my guess would be fouled carburators.

 

[manykids]

Re: WOT Hesitation

Can I use automotive carb cleaner in the fuel or something special for marine use? Do I need to look at doing something more than an additive?

 

[tashasdaddy]

Re: WOT Hesitation

to me sound like an air leak at the carb or adjustment. also that an induction timing light and hook it on each plug wire to see if you are losing spark on one cylinder or intermittent spark. do this spark test in the boat at speed. cannot be done on muffs.

 

[imported_lorin]

Re: WOT Hesitation

I guess when you say the oil pump you mean the vro fuel pump which pumps and mixes oil and gas. There is no separate oil pump. If the vro is not getting sufficient oil an alarm should sound. It does not shut down the motor automatically. There is also no choke. There is a primer solinoid which shoots fuel into the carbs for cold starts. I wouldn't start making any adjustments to the carbs but you may need to remove and clean them. You may first try draining them to see if any water or gunk is present but if they are fouled they usually need to be clean. Spraying in carb cleaner will do absolutely nothing to help.

 

[stinger700]

Re: WOT Hesitation

could it be timing? Make sure the timer base is moving freely. if the reeds were bad u could run it and see if any air comes back out in other words they are not sealing on the compression stroke.