150 Optimax

[Gypseas]

Got out a few days ago just to come around the Wiffin Spit and find it too rough in the open.
So I was taking it easy on the throttle say around 2000-3000rpm you know trying to keep it on the plane without slamming too hard. The outboard temp got too high to the point where it would not rev up higher than 2000rpm. High temp alarm came on and when checking the temp found it at 89deg Celsius.
Is has happened before, took it at the Mercury Marine they changed the water pump, checked the thermostat all looked clean they said no problem.
Anyone out there with the same problem? When at cruising speed temp in the motor shows between 29-31 celsius.
Thanks

JUST FISHEN'

[wolf]

Did you hit a chunk of kelp ???and it got wrapped around the intake cooling ports??? AS I have had the temp go up on that before??? cut the corner coming into the basin entrance from that kelp bed that sticks way out.
how is it now??


Wolf

Blue Wolf Charters
www.bluewolfcharters.com

[Gypseas]

Nope no kelp in the intake just going too slow, not enough water through the motor I guess. Water coming out of the telltale hole was warm not hot by any means.

It's never done it while running at cruise. Say I come out of the slow zone with a temp of 72°C as soon as I punch the throttle to come on plane the temp will go down to 29°C in a matter of seconds.
Hows your 225Opti behavin' ? Will it let you troll on it without overheating? When you slow down to park the boat does it start steaming at all?

Thanks Wolf!


JUST FISHEN'

[wolf]

That seems weird to me as it shouldnt matter how fast or slow your going a pump is a pump maybe time for an impeller check????
As for my engine I think it is great no problems as for the steam you see I think it has to do with the compresser that is on them ????
I can troll on it if I want but have never had to cause if it that rough out there I dont want to be out there LOL LOL


Good luck Wolf

Blue Wolf Charters
www.bluewolfcharters.com

[beemer]

could be a bad sensor. What year is the engine? if it is a 2000 or 2001 , they had sensor problems .The sensors have a plastic base that gets cracked and gives a high temp reading putting the engine into "guardian" mode. Try replacing the sensor with a brass based one. let me know how it goes.

[Charlie]

Once upon a time and the only time I’ve had that problem: I ran one of my outboards up on the beach and filled the entire water cooling system with sand. I ended up replacing the impeller, then had to go back and clean the water passages - as it ran hot at an idle. I cleaned the water passage first running water backwards through the telltale hole as a friend suggested. Then finally had to take it back apart to clean each line.

It sounds like it can only be one of these four things (that I know of). And I would check them in the order listed. Impeller, clogged/loose water tube/passages, thermostat, sensors. If you have just changed your impeller make sure you don’t have any salt deposits, sand, mud, or kinks clogging the internal water tubes/passages. Make sure your internal tubes have a good connection and aren’t loose! [u]Check your screens and STRAINER!</u> Just a small amount of salt deposit or sand will make it run hot at an idle. If that doesn’t do it I would change the thermostat (even if it tested good), and then any other associated sensors.

Oh... just for giggles! Make sure your timming is set right!

[GLG]

Have a search on this website for others that have had this problem. http://www.marineengine.com/discus/m...79/12479.shtml
GLG

[wolf]

Charlie you just made me think of something that used to happen !!!!
It may be a blocked tube as I know there was a problem with the rubber gromet at the engine block restricting the flow You may want to phone either merc or alpine (btw my best friend works at alpine/morrison) tell him I sent you i can give you his number gypseas pm me if you like.

Good luck Wolf

Blue Wolf Charters
www.bluewolfcharters.com

[Gone Fishen]

[quote]Originally posted by Gypseas
It's never done it while running at cruise. Say I come out of the slow zone with a temp of 72°C as soon as I punch the throttle to come on plane the temp will go down to 29°C in a matter of seconds.

JUST FISHEN'
When your temp rapidly drops to 29 this is because your poppet valve has taken over for the thermastats due to higher water pressure. Thermastats are only active at lower rpm's. Sounds like your overheating during this transition stage. A faulty poppet valve is a possibility but unlikely. Sounds like not enough water pressure or water volume. Before pulling out your hair have your waterpump rechecked. Assuming impeller is ok check all gaskets are correct and sealing properly, check for correct upper housing there is one that looks and feels correct but leaves a small space between housing and impeller plate. Another common mistake is a pump kit is installed but the lower pump housing is not removed and the housing and gearcase intakes are not cleaned out. They can be plugged with an old piece of impeller or barnecles. Good Luck
Oh ya: Some of the pumps have a rubber or silicone bead at the back of the waterpump base preventing exaust from entering the water cavity.
I'm setting priorities & making time for fishing.

[Gypseas]

Thanks for the help guys!
The motor is a 2003 with 250hrs and under warranty until 2010 (long story)
Had a new pump impeller installed a year and a half ago and last service at the Merc Marine they said thermostat was pulled and all looked spic an span no problems. 380 bucks later that is [8)]
GLG done some reading and found this

quote:
I was just reading what Snowbird had wrote earlier about a tech telling him his optimax wasnt supposed to be run for any length of time in the 2000 r.p.m range. The tech was telling the truth. The reason for it is this. There is two modes the optimax runs in. Homogeneouss and stratified.
Homogeneous fuel is injected on the intake stroke and dispersed.
Stratified fuel is injected during compression stroke
Simple terms, stratified fuel charge is an ultra lean burn for fuel emissions at low load. So when you run it around the 2000 r.p.m it hasnt changed into the homogeneous fuel stage, so your engine is running extra lean, and more likely to cause damage. Therefor optimax you should either idle, or run at higher r.p.m. They may have fixed this on newer model optimax's I'm not to sure. Anyway i just thought i would throw that in there so you know why he said that.

Guess next service I'll have to pound at it again.
Cheers!


JUST FISHEN'