Spark plug

[bkedman]

I have a very old Johnson 7.5 sea horse. Looks like it's from the 50's.

I snapped one of the spark plugs:passout:. I took the broken one into Baxter's and asked for two replacements. I installed the new plugs but I can't get my motor to turn over.

To be fair I haven't run the motor since last season; however, this is fresh gas and there were no signs of issues before I clipped the plug. Did I just get the wrong size plugs? How can I find out what type of plugs should be in such and old motor? For that matter how can I find out what year the motor is? There is a slight tear in the boot for the number 1 plug but it seams to seat correctly.

Any suggestions would be great.

Thanks,

[MattPark]

It's possible that the (incorrect) plugs project too far into the cylinder, not allowing the piston to come all the way up. An easy way to check would be to pull the plugs and try to turn it over.

[Okie]

There numerous things that could be the trouble. Is the engine frozen up? when you say it will not turn over this could mean the rings are stuck to the cylinder walls. If the engine has not been used for a very long time the water pump will be bad and needs repairing before it is started. If gas was left standing in the carburator, it could be fouled up and needs a real good cleaning. It's not impossible to get it runing but it will take some good mechanical work to bring it back to operating condition. If you are a mechanic you can do it. The expense of having a repair shop do it may be to high to make it worth while. It's your call as to what you want to do with it.

There is 7.5 hp Johnson outboard engines for sale on e-bay for $100 dollars are less for parts. Don't know if they will run or not.

Good Luck.

[bkedman]

It's been about a year since I last ran the motor. I've always run the motor out of gas on each trip and work hard at using fresh gas. It has not been in salt in the last four years. Traditionally it would start fairly easily.

The pull start seems to go through all the motions okay. If I disconnect the gas can there is gas in the line and if I take the gas cap off there is pressure built up in the tank so the fuel system seems to be working.

Every once in a while it will 'spit' at me when I'm trying to start it. It sounds and acts like a pop can that's been shaken up and opened. Otherwise all my attempts to pull start are fruitless.

Thanks again for the input. If I can get this going I'll use it for my reverse and take the reverse bucket off my 150 and stop that sucker from popping out of the water on me.