water pump installation on a 1981 johnson 7.5

[Senior 8-Ball]

could anyone help tell me why a newly installed water pump on a johnson 7.5 not work

 

[Vic.S]

is it really not working or is the telltale just blocked

if really not working suggestions:

the impeller drive key is not in position

the water tube is not fitted into the water pump, or grommet missing

If it was later model I'd suggest that the upper water tube grommet is obstructing the water flow but I don't think that applies to the 81 model

 

[Senior 8-Ball]

Not sure, Just know that we started it in water and wasn't working we did notice a filtered type of ven't seemed to be full of crud down by the prop We are new to working on outboard motors so we are not sure if that is the telltale you are talking about.

 

[interalian]

The "filtered type of ven't" is the water inlet. If blocked, no water gets in. And on my '82, the telltale hose was crimped under the CD powerpack and was blocked. I put a longer tube to go around the pack. The teltale is on the starboard rear underside of the cowl.

 

[Vic.S]

Not sure, Just know that we started it in water and wasn't working we did notice a filtered type of ven't seemed to be full of crud down by the prop We are new to working on outboard motors so we are not sure if that is the telltale you are talking about.

As interalian says the strainer behind the prop is the inlet... clean it!

Puzzled as to how you know you think you that the water pump is not working . It's the telltale located in the rear stb'd corner of the lower cowl that tells you if the pump is working. It should pee a strong jet of water if the pump is working. They can however become blocked so the first thing to do when there is no pee is to check that the tell tale, or its hose, or the connection on the exhaust cover plate is not blocked.

I recommend that you read the owners manual ... which should be available from iboats if you have mislaid your copy

 

[Senior 8-Ball]

We cant check the water pump because the motor only runs 4 seconds . It gets spark .Seems to get gas to the carb but after it run4 sec. it quit. have to let it sit a day or two then it does it again. runs a little , quits this is amazing to me Have worked on snowmobiles a lot. never had this problem. can someone HELP??

 

[interalian]

Maybe explain how you're trying to start it. On my old 7.5, I'd pump the primer bulb until firm, pull choke, set throttle to START position and pull the rope. After a couple of pulls, it would start then stall. Push choke half way in and it would start on the next pull, then need the choke pushed all the way in.

BTW, there's enough fuel in the carb after pumping the bulb that the engine will run for about 5 minutes.

 

[Senior 8-Ball]

I have had my motor for about 10 years and never had a problem starting it until I had it out this year and thought My water pump wen't out.I didn't notice it wasn't peeing out water for about 2 or 3 minutes after running in to shallow water.So I changed the water pump but the pump still wouldn't work.found out the telltale was blocked now the pump works but the engine won't stay running for more then 4 or 5 seconds then stalls then won't start at all until next day after it sits.I checked the compression and it was 75 in both cylinders. My question is is it possible it could be some damage internaly even though it has good compression.It seems to not be getting fuel from the carb to the spark plugs.the plugs are good but show no sign of fuel.