Both engines idle rough and then die

[Scuba_ref]

@HELP just put in the water and after idling away from the dock both engines started running rough and then would die. I was able to get back to the dock by restarting the engines multiple times and idling back.

Checked the plugs and the impellers and it all looks good. The only thing I did between this outing and the last on wed was clean the screen in my bilge.

Any ideas?

 

[Murf'n'surf]

2 things to try:

Try running with engine hatch open.

Have someone sit on clean out hatch.

 

[Murf'n'surf]

First run of the season??

Bad gas? Fogged engines last fall?

 

[Scottintexas]

the fact that both engines are running rough and cutting out would lead me to believe either as Murf said the engines are starved for air or bad gas,

maybe a loose ground cable on your battery? I had an intermittent stalling problem last year because of that,

 

[Scuba_ref]

4th time out this season and it has been running like a champ. I just pulled a spark plug wondering if one or more of them have gone bad? I have 8 new plugs enroute with a daughter assuming she can find some. The boat ran great on Wednesday and I haven't done anything since...no new gas.

 

[Englewoodcowboy]

Can you post a pic of the plug that is out?

 

[Murf'n'surf]

Doubt it's plugs.

Exhaust leak is my #1 followed by clean out hatch switches and safety lanyard.

 

[Scuba_ref]

How do you remove a stuck spark plug?

 

[Scottintexas]

is it number 3 spark plug?

The thing you should keep in mind is both engines are doing the same thing at the same time,

spark plugs can cause a lot of different crazy symptoms but it would be very unusual for it to be bad spark plugs in BOTH engines at the same time,

 

[Geiger41]

Im stumped ???? @txav8r

 

[Scuba_ref]

Doubt it's plugs.

Exhaust leak is my #1 followed by clean out hatch switches and safety lanyard.

Even though it starts right up each time I turn the key you think it can still be one of the kill switches?

 

[Murf'n'surf]

Very carefully! Don't force it. You are best to wait for a cold motor and soak with PB Blaster.

 

[Scottintexas]

put your plugs back in and try to run it right now with engine hatch open to give it plenty of fresh air,

you want to rule things out before creating more variables

 

[Murf'n'surf]

Even though it starts right up each time I turn the key you think it can still be one of the kill switches?

I don't think it's switches.

Will it run with engine hatch open?

 

[Geiger41]

Maybe the throttle cord is slipping some ??? If you keep the throttle up a little does the problem persist ??

 

[Scottintexas]

again I will say plugs are going to be down on my list of possibilities but I have to ask when the last time it was that you changed them?
If you never have be very cautious especially with the #3 plug as it has a history of being seized on the MR1 motors and breaking off in the head.
I would urge you to rule out other things before possible creating other issues.

 

[Englewoodcowboy]

Check air filters, they are a paper tye element and if you fogged the motor or oiled it or they could be just old and failing. Might want to check them as well. Being both motors I am leaning to bad fuel though, as others have stated to effect both there are just a few things it could be and fuel would be the easiest explanation.

Edit: By bad fuel I am meaning you could have picked up water at the last fill up.

 

[Scuba_ref]

I boght the boat last year and all the service was done then. So it has 10 months on the.plugs to my knowledge. I put the plug back in that I took out

I have the hatch open and now the engines won't stay running At idle. If I give it a little throttle then it will stay running ...it just quit...for a while.

 

[Geiger41]

So it still quits AFTER keeping the throttle up a little bit ??

 

[Scuba_ref]

Check air filters, they are a paper tye element and if you fogged the motor or oiled it or they could be just old and failing. Might want to check them as well. Being both motors I am leaning to bad fuel though, as others have stated to effect both there are just a few things it could be and fuel would be the easiest explanation.

Edit: By bad fuel I am meaning you could have picked up water at the last fill up.

Haven't put any fuel in it this year. Topped the tank off last yeas with marine stability and ran it through the system.