150 EFI water pump trouble

[pancakes]

i have a 2000 150 EFI with an apparent water pump and/or impeller failure. had the boat out last night and noticed it was not pissing. so, shut the motor off and felt the head which was VERY hot. also noticed quite a bit of steam coming out of the pee hole. so here come the quesitons:

1) is my motor toast? when i got it back to the dock she ran fine on the direct hose in but the water coming out initially was to hot to touch. what's the best way to determine if damage was done?

2) does anybody know of a good step by step post for changing the water pump/impeller? do i need any special tools?

3) isn't there supposed to be an alarm that alerts me when the motor's over heating? this is my first merc., but in the land of yamaha, this motor would have sounded an ear splitting sustained alarm and probably shut itself down. is there a way to test the warning buzzers to make sure all is functional? the gauges in the boat are non functional and that's next after the impeller, but i thought i may be able to rely on the motor waring system. guess not...


thanks all...

 

[gss036]

Re: 150 EFI water pump trouble

Do a compression check to see if there is damage. Yes there is supposed to be an alarm for high temp. The sender is normally located on the upper starboard head. It is just a popper type button that opens up when overheat occurs and resets itself on cool down. I am thinking about 240 degrees or so for the alarm.
No special toolseeded for the water pump. Do a search on this forum, there are several links and instructions on the job. Pretty straight forward. Much easier w/ a helper. I think you will need pt# 46-96148A/ same part but different number from DougRussell.com 46-42579A4
Those numbers are for the heavy duty pump/impeller.

Look here: http://forums.iboats.com/showthread.php?t=244200

 

[skynyrdcat]

Re: 150 EFI water pump trouble

Not familar w/ your engine, but if the OH sensor has two wires, touch them together (with the key on), if it has one wire, ground it to the power head.

If you can't find the instructions you need, email me at terry08@duo-county.com I think I've got a PDF file that will help you out.

 

[pancakes]

Re: 150 EFI water pump trouble

this is great, thanks for the help. i'm getting ready to crack open the motor this morning and figured i should also check the condition of the thermostat(s) and "poppet valve???". any advice on servicing these items?

thanks again.

 

[pancakes]

Re: 150 EFI water pump trouble

okay, i replaced the water pump and t-stats. when i cranked up the motor, two curious things happened. 1) the motor was not peeing even though i was on the direct hose. it used to pee when hooked up directly even when the motor was not running. are the new t-stats keeping the motor from peeing? 2) after about 3 minutes running, the starboard powerhead heated up much hotter than the other and still the motor would not pee. could it be that i just need to let it run longer? it seems like the the motor is getting plenty HOT, certainly enough to open the t-stats. how hot do these mercs run? i am used to a yamaha powerhead which is always warm at best. could it be that i have no overheating issue at all?

please help. i'm scared to run my motor!

thanks

 

[j_martin]

Re: 150 EFI water pump trouble

okay, i replaced the water pump and t-stats. when i cranked up the motor, two curious things happened. 1) the motor was not peeing even though i was on the direct hose. it used to pee when hooked up directly even when the motor was not running. are the new t-stats keeping the motor from peeing? 2) after about 3 minutes running, the starboard powerhead heated up much hotter than the other and still the motor would not pee. could it be that i just need to let it run longer? it seems like the the motor is getting plenty HOT, certainly enough to open the t-stats. how hot do these mercs run? i am used to a yamaha powerhead which is always warm at best. could it be that i have no overheating issue at all?

please help. i'm scared to run my motor!

thanks

The pee stream comes from water that has passed through the thermostats, so no stream for a minute after a cold start would be normal. It should, however, start to eject water when it gets hot, like 140 degrees. Both heads should be about the same.

I suspect you missed something in the water pump repair, such as the drive pin for the impeller.

Sure would help if you had at least a pressure gauge on it that works.

hope it helps
John

 

[pancakes]

Re: 150 EFI water pump trouble

hey john, thanks for the reply. yip, ran it a little longer and sure enough, she pees! the pressure gauge does work and i'm getting about 5-10 psi idling. i was just a little freaked out by how hot the powerhead got but i guess it's about 140 to 180. normal? the starboard powerhead is still about 10 degrees hotter so i guess i'll be looking into that. any idea how i might check to see if my overheat alarm is functional?

thanks

 

[j_martin]

Re: 150 EFI water pump trouble

hey john, thanks for the reply. yip, ran it a little longer and sure enough, she pees! the pressure gauge does work and i'm getting about 5-10 psi idling. i was just a little freaked out by how hot the powerhead got but i guess it's about 140 to 180. normal? the starboard powerhead is still about 10 degrees hotter so i guess i'll be looking into that. any idea how i might check to see if my overheat alarm is functional?

thanks

Hi,
If mine were running obviously uneven hot, I'd check the spark plugs. If they are normal, then go on to the cooling system.

You are looking for water intrusion (steam cleaned brand new looking plug) or lean running. (light grey instead of shopping bag brown plug) Either one can cause overheat, and either one will grenade your engine in short order.

On the cooling system, first test the thermostats.

Sometimes the ports in the exhaust chest will plug up. It's easy to get at, and if it's ever been overheated, the divider seal is probably bad and needs replacing anyway. Go gentle on the gazillion small bolts. You don't want to break any of them. Chase the threads and clean up the bolts before reassembly.

The overheat sensor is a thermodisk sensor on one of the heads. It has one wire going to it, and that wire goes to a screw, along with the alarm wire from the oil alert module. Grounding that wire with the key on should sound the alarm. Sometimes corrosion builds up under that thermodisk and insulates it from the head. Cleaning it up is usually all that is necessary to make it operational.

If you put a clip lead on the sensor, and connect an ohmmeter between that and the wire coming from the sensor, then throw it into a pot of boiling water, the ohmmeter should go to near zero when it heats up.

hope it helps
John

 

[pancakes]

Re: 150 EFI water pump trouble

good stuff, thanks john.