runs great with the muffs on! stalls under load in water!!!!!!

[couger300]

you guys have been very helpful! so i figured i'd post my next problem. I have a 96 johnson 90hp that is giving me a headache. boat ran great when i test drove it and the first time i took the family we were very happy with its performance. the past 2 times it has fired right up and will run fine until i put a real load on it. anything past half throttle and it will bog down and stall. then it wont idle anymore but will rev up in neutral. the engine has never stalled while running with the muffs on it. the only thing that i have done between the time it ran well and now is add gas. ive checked the fuel lines for cracks and blockages. i just dont get why it will only do this under load. what changes from the muffs to the lake. something in the lower unit? timing? any advice would be greatly appriciated. thank you. im confused!!!!!!!!!!!!!

 

[atlapp]

Re: runs great with the muffs on! stalls under load in water!!!!!!

I would check compression first thing and go from there!

 

[fireman57]

Re: runs great with the muffs on! stalls under load in water!!!!!!

Could be dropping a cylinder or two. These engines will run fine at idle on one bank of cylinders but not when you want to go somewhere. Check your spark with a timing light when you are out and see what you find.

 

[couger300]

Re: runs great with the muffs on! stalls under load in water!!!!!!

i would love to be able to take it out and test stuff but uts getting old paying for a tow back!!! could it be the e10 gas? I pumped out some gas after disconnecting the fuel line to the pump and it looked good. wasnt cloudy or seperated. i also will be checking compression today. anything else i should check?

 

[ondarvr]

Re: runs great with the muffs on! stalls under load in water!!!!!!

Revving the motor on muffs means nothing, so don't assume there is something different taking place other than there is no load on the motor.

There will be 10 posts saying it's the E-10 fuel, even though there is little to prove it had any to do with it.

When it starts to die try two things.

1. pump the squeeze bulb, if this works there is an air leak or an issue with the fuel pump.

2. hit the primer button as it dies, if this helps there may be a restriction in the carb, as in, gunk has plugged something up.

You can also.
Check for spark, check compression and drain the float bowls on the carbs and look for water or gunk.

 

[couger300]

Re: runs great with the muffs on! stalls under load in water!!!!!!

any idea how i can drain those bowls? as you can tell i'm very new to this and my manual is still at least a week out for delivery!! thanks

 

[couger300]

Re: runs great with the muffs on! stalls under load in water!!!!!!

ok so I figured that one out. The gas out of the bottom bowl was milky and had water in it the top was fine. I guess im wondering what issues that could cause as i dont really know the workings of a carb. how would water in the bowl effect engine? how does the carb work internally? sorry so many questions!

 

[ondarvr]

Re: runs great with the muffs on! stalls under load in water!!!!!!

There is screw plug on the side of the lower part of the float bowl, if you take it out the gas will drain from the bowl. The main jet is hidden way back inside that hole too, with the right slot screwdriver you can pull it out and clean it.

I don't have time to look for one right now, but you should be able to find a parts list and schematic online.

 

[fireman57]

Re: runs great with the muffs on! stalls under load in water!!!!!!

water in fuel will cause it to run like spit. water doesn't burn. put a water seperator inline and empty that tank and start with fresh fuel.

 

[couger300]

Re: runs great with the muffs on! stalls under load in water!!!!!!

gotcha on the seperator. heres the part thats throwing me for a loop. if i pull the fuel line before the pump and pump some into a glass there is not a spec of water. when i drain the bowls there is always water. ive repeated this process at least 5 times with the same results! can the carbs hold that much water?

 

[ondarvr]

Re: runs great with the muffs on! stalls under load in water!!!!!!

Leave the drain plug out and pump the bulb, this will flow fresh fuel through the carb and purge the water. You can also spray some carb cleaner in through the drain hole to help flush it.

 

[couger300]

Re: runs great with the muffs on! stalls under load in water!!!!!!

there was no water in the gas. so i figured id check the oil tank look at this

 

[fireman57]

Re: runs great with the muffs on! stalls under load in water!!!!!!

What oil? that is a big problem. have you figured out how it got there?

 

[couger300]

Re: runs great with the muffs on! stalls under load in water!!!!!!

i have no idea where it came from. i just bought the boat. i have had it out 3 times and it has been run for maybe half an hr while in my posession. the tank has no cracks the line is solid i really dont know. i just hope it wasnt run like that for a long time. the guy i bought it from said he hasnt used it since last summer. what problems and symptoms should i keep a look out for?

 

[fireman57]

Re: runs great with the muffs on! stalls under load in water!!!!!!

drain it, refill it with fresh oil and make sure you purge your lines. Go run the boat and have fun but keep an eye on the tank and make sure no more gets in.If you see a little you will have to figure out where it is coming from.

 

[BonairII]

Re: runs great with the muffs on! stalls under load in water!!!!!!

i would love to be able to take it out and test stuff but uts getting old paying for a tow back!!!

If you're testing your motor...you shouldn't be straying too far from the launch in the first place. I don't own a kicker motor, but I make sure to have an electric trolling motor on board.