mariner 150 efi

hello, can any one tell me if my engine has a safe mode? its a 95 mariner 150 efi
thanks

Re: mariner 150 efi

It has no safe mode, just a horn alert system....

Re: mariner 150 efi

so let me ask this...the engine will run great for about 10 to 15 min then start bogging down,like its on half power and stay that way ,and if i keep on throttle about half way ,
after a few min,the overheat alarm goes off.not the oil alarm because its been removed "pre mix".Iv noticed that when im at full speed the pee stream seems sporadic ,sometimes it just sprays a little.But at lo speed and at idle it seems stronger.Now iv replaced water pump,rebuilt poppit,and new t stats. If im losing water psi for some reason will it cause engine to bog down like this.
thanks

Re: mariner 150 efi

Check the spark on both banks of cylinders when this happens as it sounds like you may have a stator dropping a bank. This would cause engine to to lose 1/2 its power and rpm plus increase load on engine causing a overheat alarm. If it is a water problem it would cause pistons to sieze and lose power and maybe a alarm. Just for giggles what is compression of all the cylinders?

Re: mariner 150 efi

averaging about 120 psi per cyl.give or take a pound or two.ill take it to lake tomorrow and run it again and check spark .

Re: mariner 150 efi

well its hard to check spark when boat runs fine .admit i didnt run far because alarm went again so just putted back to ramp.noticed pee stream had alot of steam coming out and pee was intermittent.i read on other sites that a worn out exhaust manifold can cause symtoms like im having .any thoughts out there?

Re: mariner 150 efi

Was the old impeller weak or damaged?

Re: mariner 150 efi

it looked ok no damage a little stiff but still flexable

Re: mariner 150 efi

Replace it, see if by chance it runs better, could be high speed windings, need DVA peak reading voltmeter, voltage of high speed windings at cranking should be around 40 volts. If Stator is bad inquire about "red stator" upgrade. Manual?
Remote starter switch? (Sears)

Re: mariner 150 efi

If Stator is bad inquire about "red stator" upgrade

Click to expand...

Is no red stator upgrade for 40 amp systems, only engines I know of that use red stator are the 2-4 cylinders and where a POS...

Re: mariner 150 efi

fdhfdhaab said:

so let me ask this...the engine will run great for about 10 to 15 min then start bogging down,like its on half power and stay that way ,and if i keep on throttle about half way ,
after a few min,the overheat alarm goes off...............
thanks

Click to expand...

A failing fuel supply will cause a low in power and over-heating if you persist in continuing to run the motor, soon melting pistons and creating a $$$$$$ repair bill.

The first place to check could be the fuel tank vent, a restriction here won't immediately starve the motor until the fuel flow pulls a vacuum in the tank greater than the fuel pump can pull, the motor begins to starve.

Re: mariner 150 efi

yeah iv checked the tank before when its acting up ,opened the cover and even pumped primer and no change.noticed the primer bulb was alittle soft when i did this not sure if thats normal.but i went ahead and pulled lower unit last night to rebuild water pump again, and also noticed that there is alot of exhaust carbon on the drive shaft.IS THAT NORMAL?any way thanks for input,you guys are great.

Re: mariner 150 efi

ok ,rebuilt water pump and took it out yesterday.once again ran great for about 10 to 15 min at wot but when i slowed down and stopped and then tried to take off again, once again vary sluggish ,no power.so i idled back to ramp and started pulling plugwires one at a time to see if ihad a good spark ,i could hear it ticking pretty good under the cap."even used a timing light'.after setting at the ramp and tinkering with it i noticed that it started to smoke a little ,and sounded like it was idleing a bit better.again so i took off and just ran a short distance and it ran good again.any thoughts?

oh and if its getting spark on all six,do you think that thers any reason to DVA /

Re: mariner 150 efi

fdhfdhaab said:

well its hard to check spark when boat runs fine .admit i didnt run far because alarm went again so just putted back to ramp.noticed pee stream had alot of steam coming out and pee was intermittent.i read on other sites that a worn out exhaust manifold can cause symtoms like im having .any thoughts out there?

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The P stream of itself is controlled by the T-stats and is often intermittent it and near idle speeds.

HOWEVER, at NO TIME should you see steam!

This is often an indication of combustion gases leaking past a head gasket into the cooling system and displacing water.

If this steam is only while running at larger throttle openings then I would SERIOUSLY consider pulling the cyl heads for close inspection and install new head gaskets.

Re: mariner 150 efi

thank you for reply ,but wouldnt compression check show bad gasket?low comp in one side.

Re: mariner 150 efi

Often if a gasket is blown there will be a corresponding drop in compression on THAT cyl. However, if the leak is SLIGHT, it may not show more than a lb or 2 difference in compression, yet once the cyl FIRES, and cyl pressure rises to ??? 2000 psi THEN combustion gasses will leak into the water passages.

Check compression again very carefully to verify EXACTLY what they are. I often use a paint pen and write the #'s on the heads soo I can see any change from year to year.

Another possibility is the powerhead base gasket to the mid, the exhaust passage is next to the water passage from the pump, a leak here can lower water pressure and cause higher RPM cooling problems.

Do you have a water pressure gauge tapped into the top of the block? This is a VERY USEFUL tool in determining cooling problems, great preventative maintenance as you CONSTANTLY have a gauge to monitor cooling pressure.

Either head or base gasket problems are often able to be determined by what is happening with water pressure.

Re: mariner 150 efi

ill check those things ,probably go ahead and replace head gasket . no psi gauge .have one in dash went bad a while back and un hooked it ,guess ill get another. as far as base gasket i just replaced a few weeks ago,thought that it was a problem because it was leaking water at bottom of block.
oh andanother thing noticed some spray of water coming out of exhaust port on back of motor.???thank again.