1994 force 9.9 heating

[kev2148]

I have a 9.9 that keeps over heating with or with out thermastat in. and it keeps blowing seal to upper part of lower unit.it will **** good when cool and as it heats up the water will dribble down have new water pump on it and can blow air threw the tube off the water pump and all is clear any tips?

 

[roscoe]

Re: 1994 force 9.9 heating

There must be an obstruction or problem in the powerhead if water flow is being affected so much after warming up.<br /><br />Did your old water pump break apart? Maybe a chunk is lodged in the powerhead.

 

[kev2148]

Re: 1994 force 9.9 heating

no the water pump did not come apart, the thermastat that was in had gotten stuck and over heated it but the impeller was ok i just had all apart an replaced it so i could trust it.I was not shure can't think of anything that would be in it that could cause this problem <br />Thanks to all that reply and help.

 

[FlyBoyMark]

Re: 1994 force 9.9 heating

Next question; How big a load are you pushing, what prop is on it? If it is a small load does it "get up and go", another words, does it plane out and rev up? Could be lean fuel mixture? Is it "spittting" water spray out the upper exhaust port? Internal water tube may not be seated properly from the lower unit, missing o-ring? Take the cowel off and put ingear with spark plugs removed, turn the flywheel, does it trun easily?

 

[kev2148]

Re: 1994 force 9.9 heating

yes it turns easy, I am a merc machanic good on the bigger engines and i/os but not worked on many of these little one's have gone back to automotive work for in this area not alot of places to work willing to pay well.the biggest thing for me is the water in my lower unit after it over heats put new seals in it and the one below the water pump is were the water is coming in at it only has one seal instead of two like the bigger engine's just thought ther maybe something i am over looking or forgot about the load is good on a 40'x20 ft river boat ways about 500 plus us total 550 so should not be bad.

 

[FlyBoyMark]

Re: 1994 force 9.9 heating

Is it "spitting" water out the exhaust relief port? You say the motor is on a 40' X 20' raft? The drag alone will slow the motor down considerably...you need to change the prop to a lesser pitch......If everythng else is working and your pushing this huge boat, there's your answer, your lugging the motor to death....certain death for two cycle engines.

 

[diggerdan17]

Re: 1994 force 9.9 heating

sorry to crash the party. hey flyboy ..got a quick question for you.the serial # on my force 9.9 is 0e090464 and other # is rw617532 do you know what year it is from this info?...once again sorry to go off original topic.

 

[FlyBoyMark]

Re: 1994 force 9.9 heating

Digger..I can't find all the info, but I believe its a post 1992 engine as per Mercury site. I had a link to Force serial numbers but lost it. This info I did find was off the Mercury site but only list years before 1992 which used a different numbering system.

 

[kev2148]

Re: 1994 force 9.9 heating

sorry for the 40ft but meant 40 inch.x20ftflat bottom river boat glass.

 

[jim dozier]

Re: 1994 force 9.9 heating

In addition to lugging the engine which was mentioned, I wonder why the seal keeps blowing in the lower unit. I don't know that engine but that points to something amiss down there. While you have the lower unit off blow water up through the pick up tube in the middle unit with the thermostat out and check for flow. You could still have an obstruction that would let air by but not much water. Perhaps you damaged the head gasket when you overheated. Or perhaps the water tube grommet is misaligned. Or perhaps the water jackets are clogged with corrosion. I would recheck all the seals in your water pump installation. Is there damage to the drive shaft that is affecting the life of the lower unit seal ?

 

[FlyBoyMark]

Re: 1994 force 9.9 heating

40" bottom by 20 ft long?..Thats a big boat for a little 9.9....your lugging the H e l l out of it. Thats part of the reason its running hot and I surmise you might have a few other problems.

 

[kev2148]

Re: 1994 force 9.9 heating

they do it all the time up here the boat only ways about 350lbs but i found the problem it was the drive shaft i found one and chnaged it and the seals are not buy passing water on pump nore into the lower unit.ran yesterday afternoon and did great.<br />I want too thank everyone for ther comments and help.

 

[FlyBoyMark]

Re: 1994 force 9.9 heating

There is no problem with putting a 9.9 on a boat that big...jus' have the rite prop......Stock prop is too much pitch

 

[kev2148]

Re: 1994 force 9.9 heating

what size of prop do you say would be good?