Johnson cylinder sleeves

[rcb130]

PLease, does anyone know the answer to my questions below?


Hello,
I have a 1995 Johnson 150 Hp V6 carbed Model J150GLEOM I am working on. I have two questions:
1. What is the cylinder sleeve material and is it hardened?

2. On each cylinder head next to the middle spark plug there is a tapped hole that goes to the water jacket. What is the purpose/use of
these tapped holes? Mechanical water gage or temp?

Thanks in advance for the help.
rcb130

 

[Chris1956]

Re: Johnson cylinder sleeves

RCB, Normally cylinder sleeves are made of cast iron. I do not know if they are treated. If the tapped hole is into the water jacket, you may install either a water temp sender or a water pressure gauge. I like the pressure gauges better as you can anticipate the wear on the water pump better.

 

[bob johnson]

Re: Johnson cylinder sleeves

I also believe all the sleeves are cast and NON hardened.....there are probably two threaded holes....more techinically ...one is a hole and the other is a bore. the hole is for a water pressure gauge pick up...the bore is for a temperature gauge sender. on the V4 the upper one is the sender for temps, the lower one is for the water pressure....not 100% sure on the V6 motors . I bet they are on either side of the temp SENSOR threaded bore.....which is between the top plug and the middle plug on the V6


bob

 

[rcb130]

Re: Johnson cylinder sleeves

Chris and Bob,
Thanks for the information. It is greatly appreciated.
rcb