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Dominick
Dominick, Marine Mechanic
Category: Boat
Satisfied Customers: 1009
Experience:  25 Years Experience as Mechanic, 20 Yrs Boat Yard Owner/Mechanic, Factory Certified
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1999 mercury 225 sport max seems to load up at idle & dies

Customer Question

1999 mercury 225 sport max seems to load up at idle & dies at times?
JA: Sometimes things that you think will be really complicated end up being easy to fix. The Marine Mechanic I'm going to connect you with knows all the tricks and shortcuts. Tell me a bit more about what's going on so the Marine Mechanic can help you best.
Customer: dies at idle some times idle seems to low?
JA: Is there anything else important you think the Marine Mechanic should know?
Customer: power head was o'hauled about 10 hrs of running time ago!
Submitted: 1 year ago.
Category: Boat
Expert:  Charles replied 1 year ago.

Hello, my name is***** will assist you.

Expert:  Charles replied 1 year ago.

Have you done a compression test on the engine?

Customer: replied 1 year ago.
110 and even.
Expert:  Charles replied 1 year ago.

Would you please post the serial number of the engine?

Customer: replied 1 year ago.
runs great other than idle?turn aprox 5900 rpm with no missing or surging!do not have that ava at this time.its a 1999 225 mercury sport pro max.
Customer: replied 1 year ago.
efi fuel injection.
Expert:  Charles replied 1 year ago.

Carb or EFI?

Customer: replied 1 year ago.
idle when it dies seems on tach to drop to aprox 500/600 rpm.
Expert:  Charles replied 1 year ago.

How is the fuel pressure on the engine?

Where the injectors cleaned when the engine was built?

Customer: replied 1 year ago.
fuel pressure is good all injectors cleaned,fuel filters were replaced.spark plgs were just replace as it has been on double oil!
Expert:  Charles replied 1 year ago.

How did the old plugs look?

Customer: replied 1 year ago.
black on tips they are serface gap plugs.
Expert:  Charles replied 1 year ago.

This is the twin ECU engine correct?

Customer: replied 1 year ago.
don't think so !only 1 and has been replaced with a recall 1 that merc had problem with!
Customer: replied 1 year ago.
I think if the idle could be adj up it might fix it.
Expert:  Charles replied 1 year ago.

You should be using the Champion QL77CC plugs. they are not surface gap.

With the serial number, I can tell you how to adjust the idle.

Customer: replied 1 year ago.
I can not get the # till tonite when I get home!
Customer: replied 1 year ago.
at this point I have to get back with you later!
Expert:  Charles replied 1 year ago.

No worries, there are no time limits here.

Customer: replied 1 year ago.
ok model# *****(###) ###-#### id# ***** ***** did some research on this and it has a idle controller on it. after looking at it I think its unhooked!the red/white wire from it is not plugged in and can't find other end.maybe if it was hooked up it might fix it.can you tell me where the wire is supose to go ?and how to adj idle up?