HELP HELP HELP, 91 merc 60hp

[jeffdjpeat]

My 1991 Merc 60hp is giving me a head ache. i bought the engine a week ago, and cannot get a tell tale flow. I have changed the impeller, cleaned the housing for the impeller, pumped water from the tell tale back through the motor and that worked fine, then i pumped a hose from the bottom end line up through the motor, and that was clear. I put her all back together, and started it up, i have water spitting out the 2 exhaust ports below the tell tale, but only steam, and the odd droplet from the tell tale itself. i am running it in a large bucket since i dont trust the muffs on larger motors. where did i go wrong?? the motor is a 91 merc 3 cylinder, 2 stroke. made in canada, serial number A717699. Also when i installed the new impellor it seemed like it was too big for the housing, took me 30minutes to force it in. did they sell me the wrong impeller? are the fins supposed to be curved a lot when in the houseing? this is my 2nd new impellor, the first one i think i installed wrong and it torn 2 fins off, but i did the water flush after that happened.
Any help Please, i wanted to try the boat out this weekend, doesnt sound like im going to get a chance!!

 

[Silvertip]

Re: HELP, 91 Merc tell tale steam, no water!!!!

Re: HELP, 91 Merc tell tale steam, no water!!!!

Are the water inlets below the water line. It would take a quite large bucket (say a trash can size) to get the lower unit deep enough. If you've starved the impeller for more than 30 seconds you best start heading to the store for another one. You do have the impeller drive key in place don't you?

 

[jeffdjpeat]

Re: HELP, 91 Merc tell tale steam, no water!!!!

Re: HELP, 91 Merc tell tale steam, no water!!!!

water inlets are below the water level, i am using a big tupperware thing. i get water spitting out the 2 exhaust ports, and the odd drop from the tell tale, but mostly steam. could the copper line from the pump to the bottom end of the motor have a bad seal? im at a loss, i replaced all the gaskets, the impellor, etc... when i hooked a garden hose to the water inlet that attaches to the pump the tell take shot 6 feet away. but now with it reassembled and running in a pail, nothing, just a drop and steam. i dont want to over heat it, do the 91's have alarms?

 

[jeffdjpeat]

Re: HELP, 91 Merc tell tale steam, no water!!!!

Re: HELP, 91 Merc tell tale steam, no water!!!!

yes the drive key is in place, i have taken it apart and put it together about 6 times now, checking everything, thinking i ruined another impeller, but all looks good.

 

[jeffdjpeat]

Re: HELP HELP HELP, 91 merc 60hp

does anyone know what may be wrong? i just took it all apart again, the impeller is still ok, after another barrel run tho, the water pump housing etc was all covered in water and grease, or oil. i need to find out why i dont have a tell tale, this is really confusing me now.

 

[Don S]

Re: HELP HELP HELP, 91 merc 60hp

Did you replace the gaskets for the raw water pump? What was the condition of the wear plate and the pump housing, even the lower pump housing.
Any of those being faulty will cause the pump to suck air and not pump water.

 

[jeffdjpeat]

Re: HELP HELP HELP, 91 merc 60hp

i removed the top plastic housing around the impeller, replaced both gaskets one under the thin steel plate and one above. and installed the new impeller. i could not get the bottom plastic base plate for the impeller housing off, so i left it in place, but cleaned it all out. so the lower pump housing was not removed, but cleaned. the thin steel plate appears to be good, no damage i can see.

 

[Laddies]

Re: HELP HELP HELP, 91 merc 60hp

It's quite common if those engines that have overheated that the plastic elbow that supplys the hose to the telltale to melt shut remove it from the engine and see if you have water flow, if you don't drop the lower unit and hook a hose to water supply tube and turn it on slowly to see if you can get water out of the telltale that way. If you still don't grt water to the telltale you probably have a bad gaskrt in the exhaust plate adapter under the engine.

 

[jeffdjpeat]

Re: HELP HELP HELP, 91 merc 60hp

i just had the motor running, i put a hose onto the tube that runs from the bottom of the motor to the pump housing, everything works. it has to be a problem with the pump sucking water. or maybe the seal around the tube from the pump to the motor. there was a rubber peice about 4 inches long around the copper pipe, and another plastic peice about the same size, but they are just on the copper pipe, they dont seem to connect anything. is there an easy way to test the bottom end without connecting it to the motor?

 

[jeffdjpeat]

Re: HELP HELP HELP, 91 merc 60hp

anymore help would be great, i would like to run the boat tomorrow, if i can get more then steam!! still trying, gonna be a long night, and a lot of cold ones!!

 

[beermunk]

Re: HELP HELP HELP, 91 merc 60hp

Put the muffs on and try again. Realize that a small pool of water in a tuppaware container probably isn't pushing the water far enough into the intake.

If that doesn't work, replace the impeller again. It's probably burned out. Make sure it's centered.

 

[jeffdjpeat]

Re: HELP HELP HELP, 91 merc 60hp

the impeller is good, just checked it again, by tupperware container, i mean its approx 20gal jug, water level is 4-5 inchs 8+ cm above the inlet fins for the water pump.

 

[jeffdjpeat]

Re: HELP HELP HELP, 91 merc 60hp

is the impeller supposed to be bigger then the pump housing? i had to force the impeller into place??? turning the shaft while installing it. the fins are curved but tight on the walls, is this typical or did they sell me the wrong one?

 

[beermunk]

Re: HELP HELP HELP, 91 merc 60hp

is the impeller supposed to be bigger then the pump housing? i had to force the impeller into place??? turning the shaft while installing it. the fins are curved but tight on the walls, is this typical or did they sell me the wrong one?

No it's probably correct - they should be curved against the housing.

 

[beermunk]

Re: HELP HELP HELP, 91 merc 60hp

the impeller is good, just checked it again, by tupperware container, i mean its approx 20gal jug, water level is 4-5 inchs 8+ cm above the inlet fins for the water pump.

Here's the issue - you may take out the impeller and call it "good" by a visual inspection, but it may be warped or out of round after running it dry. For the cost, replace it and try running with the muffs on.

 

[jeffdjpeat]

Re: HELP HELP HELP, 91 merc 60hp

impeller 3 installed, still no tell tale. the pump has to be sucking air, but where? i cannot get the lower pump housing off without breaking the plastic. new gaskets where installed on the upper housing, on either side of the thin metal plate. like i mentioned before the copper tube running from bottom of motor to pump housing had a plastic tube on it and a rubber tube on it, apparently just sitting where the tube bends. could these be the issue? it shoots a great tell tale with a hose connected to the copper tube.

 

[Laddies]

Re: HELP HELP HELP, 91 merc 60hp

Just a few more things to ponder, If there is a lot of exhaust in the tank it will pump easier than water, yes the impeller should be larger than the housing, is item #22 in good shape it could cause excess exhaust in the area of the pump. http://www.mercruiserparts.com/Show.../37.png&inbr=571&bnbr=180&bdesc=EXHAUST+PLATE
Are the gaskets on the pump plate #28&29 in good shape either could cause a leak letting exhaust into the pump. http://www.mercruiserparts.com/Show...571&bnbr=260&bdesc=GEAR+HOUSING+(DRIVE+SHAFT)
The only other thing that I can think of and am not sure if nessicary on the 60HP engines is the larger 3 cyls have a pair of alignment dowels to put in the holes that the water pump bolts go into the the gaskets, plate and housing are slid down the dowels and the other 2 bolts are put in tightened and removed and the last 2 bolts installed, I have never used then and they are still in the wrapper but there must be a reason that Mercury thinks we need them?

 

[sportsmanphil]

Re: HELP HELP HELP, 91 merc 60hp

Take the lower unit off, put the muffs on the foot and see if you have flow into the pump housing. You have already run water from the tube to the tell tale.

The impeller is not designed to and will not pump air!!!! THATS why you either need to use the muffs or submerge the LU in water. Sticking the bottom few inches in a bucket is not going to work.

 

[jeffdjpeat]

Re: HELP HELP HELP, 91 merc 60hp

i had almost the entire bottom end submerged in water, i tried it with muffs, no tell tale, checked the impeller, tried it in a pail that completely submerged the intake fins, no tell tale, checked the impeller again, and tried it in the pail with the muffs on. i havent tried just the lower end on muffs, removed from the motor, i will tomorrow, but im not sure what help i will get from that, could you explain? i know everthing is clean from the impeller up, gaskets described by "Laddies" have all been replaced. i would love to fix this myself, and not pay $79 an hour to have her serviced.

 

[saumon]

Re: HELP HELP HELP, 91 merc 60hp

... or maybe the seal around the tube from the pump to the motor. there was a rubber peice about 4 inches long around the copper pipe, and another plastic peice about the same size, but they are just on the copper pipe, they dont seem to connect anything...

When you remove the L/U, you have to remove theses seals from the copper tube (BTW, there sould not be 2, only 1). Then, prior to reassembly, you put that plastic tube on top of the water pump housing and make sure that the copper pipe fit into when bolting on.

It could be you problem if the water tube (copper) isn't aligned or sealed with the pump housing. You'll only get some water as the water tube is sucking it from the exhaust housing, wich is filled by the water pump. So you'll still have water but no pressure.