1991 Evinrude 155 com Overheating

[Billy Henry]

I have replaced water pump and I took it to a guy who pull the heads and the power head and checked the flow of water and still no luck. When I run at full power after about five minutes the alarm goes off and the top of the heads are both hot I disconnencted the heat senser to check and it is the sensers going off. I get plenty of power I just repaired bad magnets in the flywheel which was my power problem but I just can't figure out the overheating problem.

 

[Dhadley]

Re: 1991 Evinrude 155 com Overheating

Welcome!!<br /><br />When you pulled the heads did you change the deflectors?

 

[Billy Henry]

Re: 1991 Evinrude 155 com Overheating

Originally posted by Dhadley:<br /> Welcome!!<br /><br />When you pulled the heads did you change the deflectors?

 

[Billy Henry]

Re: 1991 Evinrude 155 com Overheating

No, I didn't but I will order some today and try it. I didn't know they could wear out.<br /><br />Thanks I will let you know!

 

[Dhadley]

Re: 1991 Evinrude 155 com Overheating

It's not that they wear out so much as they swell up. When they swell they can actually stick out into the water flow and slow it down or darn near stop it. Not too uncommon. OMC wanted them changed every year. I cant think of anyone who does.

 

[Billy Henry]

Re: 1991 Evinrude 155 com Overheating

I changed the deflectors and the motor ran little longer but the alarm still went off. Do you have anymore ideas? One thing I noticed when the alarm is on the motor will shake if I try to run in at high speed. I cut the motor off and wait for about ten to twenty minute and the restart and run it and as long as I go slow the alarm does not come on.

 

[Billy Henry]

Re: 1991 Evinrude 155 com Overheating

Oh correction my motor is a 1991

 

[Dhadley]

Re: 1991 Evinrude 155 com Overheating

When it starts shaking, what rpm is it at? Is it limited to about 2500?

 

[Billy Henry]

Re: 1991 Evinrude 155 com Overheating

I am not sure I don't have a RPM Meter but I would say right at the point of the boat going to plane.

 

[Dhadley]

Re: 1991 Evinrude 155 com Overheating

That sounds about right. It's probably going into SLOW (Speed Limiting Overheat Warning).<br /><br />Have the t-stats and pressure relief valves been serviced?

 

[Billy Henry]

Re: 1991 Evinrude 155 com Overheating

there is no T-stats in and how do I check the relief valves? Also do you think I have a water blockage somewhere else?

 

[Dhadley]

Re: 1991 Evinrude 155 com Overheating

If there are no t-stats the pressure relief valves may be gone too. Regardless, the T-stats need to go back in. If the relief valves are gone we need them too. <br /><br />The relief valve is a plastic & rubber piece with a spring on it under the t-stat cover.<br /><br />When you serviced the water pump did you replace the liner or just the impeller?

 

[Billy Henry]

Re: 1991 Evinrude 155 com Overheating

The relief valves are in but they may bad. I will order the T-stats and new R- valves. I ordered the whole water pump kit and replaced everything. Is the liner something else I missed? or is it the cap that the impeller goes in. because if it is I the placed in as well. This problem has been going on for about six months. So I am going to order another impeller kit and have it just in case.

 

[Dhadley]

Re: 1991 Evinrude 155 com Overheating

If you repalced the complete kit it should be OK. About the trickiest part is making sure you get that O ring in the plastic housing before the ss cup goes in. Oh - and the O ring on the platic housing too. Other than that it's a pretty straight forward job.

 

[andy6374]

Re: 1991 Evinrude 155 com Overheating

Could there possibly be a leak where the water tube enters the powerhead atop the midsection. Sometimes the grommets give out.<br /><br />Did you change out the head gaskets? If there are blown they can allow exhaust gases to creep into the cooling system.<br /><br />Just tossing some additional ideas out there. You'll definitely figure it out with Dhadley as your guide.<br /><br />Good Luck

 

[Billy Henry]

Re: 1991 Evinrude 155 com Overheating

Can you think of anything else I will need to order or check to relief this problem.

 

[Dhadley]

Re: 1991 Evinrude 155 com Overheating

It may be as simple as the t-stats being gone are allowing the water to pass thru too quickly. Or not allowing the block to fill completely. And that's not good for the water coled rer/rec.<br /><br />The motor was designed to have the stats in. Lets start there.

 

[Dhadley]

Re: 1991 Evinrude 155 com Overheating

Just a thought -- what spark plugs are you using?

 

[Billy Henry]

Re: 1991 Evinrude 155 com Overheating

I put in Champion QL16V Plugs

 

[Dhadley]

Re: 1991 Evinrude 155 com Overheating

Rather expensive but a good choice.