2003 Mercury EFI 200HP

[jdbarnett]

What should the normal water pressure be at idle for a 2003 200HP EFI and what should it be at 5500 RPM?

Also, if I idle for more than 2 or 3 minutes (example: getting off of a shallow flat or eating a package of crackers) my engine will alarm out when I try to get on plane. After I shut off the engine for a minute or so, it is fine. Help!

 

[gss036]

Re: 2003 Mercury EFI 200HP

Usually pressure is about 2-3 pounds at idle and 10-12 @ WOT. It does vary sometimes. Check your stats and then maybe the poppit valve for junk or sticking.

 

[Don S]

Re: 2003 Mercury EFI 200HP

When was the last time the impeller was replaced?
The impeller should be the first thing you check on any type overheat problem. They can be damaged in so many ways.

 

[jdbarnett]

Re: 2003 Mercury EFI 200HP

I replaced the impeller 11 months ago. I try to do this every 18 months or so.

 

[Don S]

Re: 2003 Mercury EFI 200HP

Here are the water pressures from the service manual.

Idle: 1.0 to 3.0 PSI
Poppet Valve Opening 4-9 PSI
WOT 12 PSI minimum.
Water pressure may be checked by attaching a test pressure gauge to the top of the engine
block.
A water pressure line (GRAY colored) is provided that exits at the front of the lower cowl.
A dash style gauge may be connected to this line to register water pressure.

 

[jdbarnett]

Re: 2003 Mercury EFI 200HP

Can you expain where the poppit valve is located. I would like to see if there is an obstruction as mentioned above. Thanks!

 

[gss036]

Re: 2003 Mercury EFI 200HP

It should be located on the lower starboard side of the block. The cover looks like a figure 8. While it is spring loaded, it will not jump out at you. There 2 gaskets, one for the outer cover, one against the block. I would suspect your engine is similar to my 89 Merc 200 hp, it is easier to access the small bolts by removing the starboard side of the lower cowling. Just 4 small bolts involved there, nothing to disconnect. Be carful that you do not break or strip out the 4 small bolts holding the poppet cover on.

 

[jdbarnett]

Re: 2003 Mercury EFI 200HP

Thank you for your help. I will look at it tonight. JB

 

[jdbarnett]

Re: 2003 Mercury EFI 200HP

Is it advisable to not only replace the impeller but put in a kit that iboats sells?

 

[gss036]

Re: 2003 Mercury EFI 200HP

Personally, I use only Merc OEM parts. If IBoats sells those, that is ok. For the price, (maybe $15 more) replace the entire pump if it hasn't been done. Merc makes a heavy duty type kit, but I think that is all they sell now. While the cup is stainless, it can wear if you have had some sand or junk go through it.