One thing after another 1991 40hp Merc

[amandanicole]

First things the motor would barely stay lit. Finally got it running and holding idle in the driveway. But then it wouldn't stay lit let alone have power on the water. Took it in and were told the water seals were cracked. replaced those. took it on the water, wont idle. did a carb clean on it and got it idling. took it to the lake again. she goes but not much. Like its not firing on all cylinders.

Any suggestion on where we (not boat mechanics) can start looking for more issues? Anything we can do without specialty tools?

 

[powderhoundbrr]

Re: One thing after another 1991 40hp Merc

First things the motor would barely stay lit. Finally got it running and holding idle in the driveway. But then it wouldn't stay lit let alone have power on the water. Took it in and were told the water seals were cracked. replaced those. took it on the water, wont idle. did a carb clean on it and got it idling. took it to the lake again. she goes but not much. Like its not firing on all cylinders.

Any suggestion on where we (not boat mechanics) can start looking for more issues? Anything we can do without specialty tools?

Simple things to start:

• New fuel filter(s)
• Change Spark Plugs
• Look at plug wires for damage
• Drain Tank and new fuel
• Check Compression
• Ensure Carb is clean / nothing sticky
• Air Filter clean

 

[Mi duckdown]

Re: One thing after another 1991 40hp Merc

What is stay Lit, what water seals?

 

[amandanicole]

Re: One thing after another 1991 40hp Merc

When you get it out on the water you have to jam it into forward throttle to get it to stay running or it will bog down and stall. Once you hit it like that then you can ease back and it will stay running. Checking spark tonight we have already rebuilt the carbs.

 

[amandanicole]

Re: One thing after another 1991 40hp Merc

So we have spark on all four. Not sure where the air filter might be, there's nothing visibly air filter like..... looking at the carbs from the oil reservoir side they are wide open are they supposed to be like that?

Think I've located the fuel filter, (white plastic part?) but Im wondering what the black box below the "air filter" is.....