NEED Help. I too got towed in...

[allen.st]

Re: NEED Help. I too got towed in...

Well I have expericenced a bit of over heating on my older stringer drive and I will have to say that mine got to 240 twice and was slowed down imeditaly. Although the motor was not hurt I did blister the inside of a new exhaust hose. you may want to check them while working on the other.

 

[rodbolt]

Re: NEED Help. I too got towed in...

most raw water carburated motors are desined to run at 140 due to the mineral content of water, be it salt or ceratian lakes. merc has bumbed up to 160 on some applications. fuel injected is almost always at 16-180 due to the sensor that controls warm up. to cool and it adds to much fuel causing other problems. above 190 is almost always a cooling system problem. the 3.7 merc has a note that at WOT 173-200 is acceptable. but experience shows anything over 190 indicates a problem. fix it now or at the head job.<br /> I agree with ya trog. 140 is way to cool for proper engine efficiency but its a comprimaise between efficiency and the formation of deposits and problems with the cooling system.<br /> thats why I like closed,full, cooling systems. so I will agree that 200 to 210 may not cause immediate damage I dissagree on if something is wrong.<br /> going back to the initial problem. if the coupler splines are sun the ball gears wont turn and the seawater pump wont pump causing a rise in temp and eventual hot oil light.if the ball gears are stripped the seawater pump does not turn and the above happens again.<br /> if the stub shaft that couples the upper case driveshaft to the lower case drive shaft,and also drives the saewater pump, is stripped the above happens again.<br /> all were common on those drives.<br /> time for careful testing. hate to see ya pull an engine to find the coupler is ok and the stub shaft or ball gears are bad.

 

[pvisser]

Re: NEED Help. I too got towed in...

Well. I am back. Took the outdrive off, and halelujah. It's the water pump shaft. Mind you the drive gears or stub shaft I think someone called it. (exposed on each end) are both worn, so I'll replace those two while I am in there, as well as the impellor, and all the seals.. Anyways, I hope to be boating again by the weekend..

 

[Reel Poor]

Re: NEED Help. I too got towed in...

BrettNC<br />What is the temperature of an engine when the guage says 190, and the engine is running without water in it because because the raw water pump drive shaft is broken, and the circulating pump has pumped most, if not all the water out of the engine? Not to mention what has probably steamed out, from trying to see WHATS WRONG at "240".<br /><br />Due to application described by pvisser, he should have been running at a temperture of 140 to 160, so at 190 degrees his application IS overheating {running above specs}. <br /><br />Based on problem found you could even suspect it may have gotten HOT at 190 and no water in it. Temp senders do not operate properly unless they are in contact with water/coolant. So the guage reading may be false. Possibly MUCH hotter.

 

[trog100]

Re: NEED Help. I too got towed in...

"Temp senders do not operate properly unless they are in contact with water/coolant."<br /><br />right on..<br /><br />this is a car experience thing but the same principle applies.. as long as the system has water in it and its still going round no engine damage will occur and the gauge will read accurate if somewhat hot..<br /><br />no water going round and the gauge will read cooler even cold.. but the internal engine temps will go off the scale.. pistons expand too much and pick up on the bores.. cylinder heads warp and valve seats can drop out.. <br /><br />i used to use the heater as a test on cars with known water leaks.. if hot air was coming out of it i knew that the engine still had water in it and it was going round.. as soon as the heater went cold that wss the danger point and time to stop..<br /><br />no way of knowing such a thing (the point water stops going round) on a boat thow.. but if the gauge goes right up then drops off dont assume your engine temp has dropped cos without water going round the gauge reading is totally meaningless and its wrecked engine time if u keep going..<br /><br />your boat should run at or near the temp that the stat is set to keep it at.. if it dosnt there is a problem and it needs fixing.. if a raw water cooled boat gets up to 220 there is a major problem.. the main one being that the gauge can no longer be trusted to be giving the true engine temp reading.. the real engine temps might be way hotter.. <br /><br />trog100

 

[pvisser]

Re: NEED Help. I too got towed in...

OK, so I'll double check the gauge when the boat is water ready. Luckily then, the engine did not sustain any damage from running hot, and probably without water in it ..<br /><br />Is there a way to install a remote temp, and volt gauge in the engine compartment? Or is the sender unit the one to question?

 

[Reel Poor]

Re: NEED Help. I too got towed in...

pvisser<br /><br />Your temp guage and sender are most likely in proper working order {considering statement in your original post of 190/240}.<br /><br />Although a compression test AND cylinder leak-down test may be in order BEFORE you splash it. Its better to know if it blew a head gasket before it gets water in the engine and causes more damage.<br /><br />The three largest KILLERS of marine engines are OVERHEATING, WATER INGESTION and FREEZE/CRACKED .

 

[pvisser]

Re: NEED Help. I too got towed in...

OK. Finally had a chance to take the boat out this morning. Ran great, temp only reached about 140 after a half hour. Lake water temp is about 7.<br /><br />All seems well in Paul's land again

 

[trog100]

Re: NEED Help. I too got towed in...

jolly good.. that 140 should stay there even when the water and weather gets warmer if everything is working right.. no real need to panic over this but if the general engine temp gets hotter with the weather it can be taken as sign that there is a flow promlem and the stat is fully open and the system is struggling to cope..<br /><br />lots of folks think temps going up and down with the weather is normal but it isnt.. the stat should control the temps nothing else.. and even in hotter weather the overall flow should be enough so that the stat never has to fully open.. it opens more and permts more flow.. but it should never have to run fully open.. if it does the overall flow system is faulty.. either restricted or the pump aint pumping enough..<br /><br />trog100

 

[pvisser]

Re: NEED Help. I too got towed in...

The stat is a 140 stat, I assumed that it worked the same way as an automotive stat. I also figured that when the lake temp increases the engine temp may increase too. (A little) especially when just idling after a good run.<br /><br />Thanks again

 

[KaGee]

Re: NEED Help. I too got towed in...

Sorry for your trouble, but glad for you that it was in the drive and not the coupler. Pulling the engine is a real B.....excuse me.... pain in the arse.

 

[trog100]

Re: NEED Help. I too got towed in...

yes they work basically the same.. the mistake most folks make is to assume that a 140 stat fully opens at 140 and thats how it works.. it isnt.. it probably takes 160 before it fully opens and by that time its no longer controling the water/engine temp other things are..<br /><br />the stat works off the water temp going thru the engine.. if the water temp starts to gets hotter for whatever reason (engine making more heat or lake/sea water getting warmer) the stat should open a little more and permit more flow and cool things back down to the 140..<br /><br />as a general rule.. engines that read hotter at idle than while running higher rpms show symtoms of a failing pump.. basically cos the pump at idle rpm aint pumping enough water.. in this case its the pump thats controling the flow not the stat..<br /><br />ignore little variations.. but all the time that gauge should read about 140-ish.. okay at WOT super hot conditions it might start to read higher.. but thats only cos the limits of the cooing system have been reached.. it shouldnt really do this.. even if mercruiser say it might do.. he he<br /><br />trog100

 

[Reel Poor]

Re: NEED Help. I too got towed in...

All seems well in Paul's land again <br />

Glad to hear the good news and there was no other problems.