1983 Johnson 115

[daddycajun117]

Ok here is the deal. I went out this weekend and overheated the motor. It was still running, but I noticed it not peeing so I cleaned it and when it started to pee it was steam. I know this is not good. I let the motor cool and then ran it. I could not get on plane. It had no power. When I got to the launch, I removed the cover and found the top right coil (if looking at back of motor) had the spark plug wire out of it. When I got home I replaced the coil and ran the motor. I checked all plugs and they are getting spark. The motor idles fine and seems ok. I went and put the boat back in the water and it still will not plane. This happened on sunday, and everything ran fine on saturday.

A friend told me he overheated his motor and it had a failsafe to only let it run on a few cylinders so it would not burn up. Does my motor have something like that? He replaced the sensor and it ran fine.

 

[ezeke]

Re: 1983 Johnson 115

Any time the 115 heats up like that, it is good shop practice to replace the cylinder head gaskets because they are likely to be blown. At a minimum, you need to re-torque the cylinder head bolts and perform a careful compression test.

The heat may have damaged the water passage deflectors, so you can inspect those while you are replacing the cylinder head gaskets.

There is no failsafe.

 

[daddycajun117]

Re: 1983 Johnson 115

what should the compression be on this motor.

 

[ezeke]

Re: 1983 Johnson 115

Readings should be within 10% of each other. I would expect the numbers to be above 120 at sea level if the rings are in good shape. Test with all sparkplugs out; you can pull your emergency lanyard to suppress fire.

 

[daddycajun117]

Re: 1983 Johnson 115

Ok Sounds good. Is there supposed to be an over heat warning on this motor. Or is there a way to put a temp gauge on or something. I will be working on this motor soon. Last time I tested compression I got around 110

 

[ezeke]

Re: 1983 Johnson 115

You can add the BRP or Teleflex gauge using the surface mounted sender and the Z bracket: http://www.downloadingfiles.co.uk/teleflexfiles/gauges/Outboards.pdf

 

[emdsapmgr]

Re: 1983 Johnson 115

The later engines have rpm limiters during periods of overheat. Your engine is too old and does not have that feature. That engine has an overheat warning horn in the control box. If either head gets over 212 degrees, it will turn on the hot horn. You may want to check the two overheat sensors/switches (one in each head) and check your horn for operation.

 

[cougar1985]

Re: 1983 Johnson 115

Ok here is the deal. I went out this weekend and overheated the motor. It was still running, but I noticed it not peeing so I cleaned it and when it started to pee it was steam. I know this is not good. I let the motor cool and then ran it. I could not get on plane. It had no power. When I got to the launch, I removed the cover and found the top right coil (if looking at back of motor) had the spark plug wire out of it. When I got home I replaced the coil and ran the motor. I checked all plugs and they are getting spark. The motor idles fine and seems ok. I went and put the boat back in the water and it still will not plane. This happened on sunday, and everything ran fine on saturday.

A friend told me he overheated his motor and it had a failsafe to only let it run on a few cylinders so it would not burn up. Does my motor have something like that? He replaced the sensor and it ran fine.

sounds like you might want to replace the impeller.it didnt over heat because of a plug wire loose!

 

[daddycajun117]

Re: 1983 Johnson 115

It overheated because I ran through some mud.

 

[daddycajun117]

Re: 1983 Johnson 115

Update..... I removed the cover and found that the coil I replaced had the wire pulled out. reason #1 it will not plane. While I had it open I checked compression and was getting 100 to 110 on all 4 cylinders. Repplaced spark plugs. My next step is to look for all the fuel leaks. It idles fine but has still been a lil funny getting out of the water and runnin.