85 hp Force cooling problem

[John692696]

I have 1988 85hp Force outboard. It is running fine. But I have notice that the tell tale is pumping water at idle and 1/4 throttle, but as I increase the throttle, the water slows downs and then stops. I have replaced the impeller and flushed the system, but it has not made much difference. Does anyone have any ideas about this?<br />Thanks<br /><br />John

 

[Forceluver]

Re: 85 hp Force cooling problem

I'm having the same problem, It does not overheat though so oh well.

 

[The Marine Doctor]

Re: 85 hp Force cooling problem

Check compression of the engine.<br /><br />You will be looking for the start of a blown head gasket.<br /><br />TMD

 

[mrtool2u]

Re: 85 hp Force cooling problem

Hey John and Forceluver,,I have a 1989 85 hp force and it is driving mr crazy.I cant seem to get my rpm's up where they belong.Can you enlighten me as to the pitch of prop that you are running and what size boat,,length and weight,and what your rpm's is if you have a tach.I have a 19 ft aluminum and cant get over 3900 rpms with just me in the boat.Motor runs like a top,just no rpms.

 

[Navigator]

Re: 85 hp Force cooling problem

John69....<br />If the water flows at idle but trickles off as the RPM increases, you have the water pump impeller blades installed backwards.<br /><br />Pull the lower unit and make sure the impeller blades bend TOWARDS the direction of rotation. This should solve your problem.<br /><br />Nav

 

[redcardref]

Re: 85 hp Force cooling problem

I'm interested in this thread myself. I have an '88' Force 125 where I have just noticed (in last week) the same problem. I had posted a thread about this, but the couple of replies I received didn't suggest any problem such as the start of a blown head gasket. I am no mechanic, but, I am curious, TMD, why would the head gasket failing, be a cause for the flow from the telltales to drop?<br />And for good measure, why are the dates of the postings in reply to the original question earlier dates than the original post?? by 2 days in some cases?

 

[The Marine Doctor]

Re: 85 hp Force cooling problem

A blown head gasket will pressurize the waterjacket and restrict the flow of the water.<br /><br />TMD

 

[dumbtoboating44]

Re: 85 hp Force cooling problem

I have an 87 85 hp Force, and I cannot get the water to flow, and the over heat buzzer comes on. The impeller looks good. I cant get it to flow with the foot removed trying to put water up it. Any suggestions on where or what to look at next? There doesnt seem to be a lot of information on out board motor cooing systems.

 

[Shifflett115]

Re: 85 hp Force cooling problem

Replace the thermostat ,water will flow then