Engine Running Problems 7.5HP Johnson Seahorse

[gone_fishing8282]

I am new with this engine as I just returned to home from being in the military and my grandfather gave me his boat and one of his small engines which is a 7.5 HP Johnson and I think it is right around a 1985 or so. The engine was hardly ever used and was stored in the basement all covered up for the past 13 years. The engine is like new but when I tried to start it I had some problems. My father told me a while back when they had it on the lake it would not start up. Well after working on it I got it to only start for a second using a little starting fluid, but it would only start for about 5 seconds, sounded really good and then shut off. It sounded like the engine was not getting any gas. I took the filter off, and it was clean looking, I removed the fuel line coming from the carb and there was no gas spurting towards the carb. Like I said I am new to these engines but it seems to me that the fuel pump may be bad. But I am not sure? I have been researching on how the fuel pump actually works also as there is no wires going to it and it seems to work from air? If somebody could help me out with this I would greatly appreciate it...

 

[Joe Reeves]

Re: Engine Running Problems 7.5HP Johnson Seahorse

The carburetor is clogged, gummed, fouled due to sitting for so long..... a common problem.

Remove, clean, and rebuild it using a complete carburetor kit.

 

[gone_fishing8282]

Re: Engine Running Problems 7.5HP Johnson Seahorse

Hi Joe,
Thanks for the advise. I know from knowledge of other engines (dirtbikes) this sometimes happens so I will give it a shot. When you say rebuilding the carb, what all do you think I will need? I know I had this problem with other types of engines before but I only had to take the carb off and clean it thouroughly and it ran fine then. Thanks again

 

[wildmaninal]

Re: Engine Running Problems 7.5HP Johnson Seahorse

Yes those fuel pumps (as long as they haven't been replaced by an electric pump) they do work off air.

If you are hooked to a portable tank and have pumped the bulb up tight, if you can get it to pump till the bulb is firm this will help prime the fuel system. If the bulb doesn't pump firm then you must have a leak somewhere in the fuel system.

The fuel pump should pump out gas (as long as your line is hooked correctly and not stopped up), it should pump out gas when cranking the motor over. So if you are not getting any gas with the line undone (that goes to the carb from the pump) and somebody is pulling the pull start or (if you have) starting the motor with the electric start then you may want to start at the fuel pump and rebuild it. When rebuilding the carbs you should be able to buy a complete kit.

Check this link out, and go to view parts catalog. You will need the model number handy. This should give you some diagrams and part numbers to help out.

http://epc.brp.com/login.aspx?ReturnUrl=/default.aspx?brands=ej&lang=e&brands=ej&lang=e

 

[wildmaninal]

Re: Engine Running Problems 7.5HP Johnson Seahorse

If you want post the model number of the motor, it should be located around the transom mounting bracket. We can help verify the year. You may find out that the motor is older then what you think it is.

I also need to add that the bulb on the fuel line will not pump firm unless all lines are hooked, then if it will not pump until it is firm then you may have a leak. There is a guage that you can hook to the fuel pump to check the preasure also.

 

[tashasdaddy]

Re: Engine Running Problems 7.5HP Johnson Seahorse

http://forums.iboats.com/showthread.php?t=244013