1998 Johnson 175 Ficht overheating

[xyourobob]

Good News: I boat a 1998 20" Whaler Outrage<br /><br />Engine: 98 Johnson 175 ocean runner ficht<br />Model #j175fsxecs, serial #g04500671<br /><br />Bad News: Engine Temperature exceeds 210 degrees in open throttle. The engine idles at 160 degrees. When I bring the engine to 3500/4000 rpms in neutral the temp drops to 155 degrees. Under pressure the temp rises dramaticaly and drops dramaticaly. <br /><br />I'm back several months later...same problem.<br /><br />My boat mechanic said that my motor is the best Johnson ever made....???????<br /><br />He replaced the impeller and plate. Said although the gauge reads 220 it is really running at 160. Well I have been using it trouble free and then wammo. Overheated today! Can it be the thermostat? or is there thermostat(s)? I'm fairly mechanical minded, can I do this myself and where are they located?<br />Any help would be appreciated, the season is slipping by <br />I have put in new plugs,Temp sensor and Temp gauge. <br />Thanks

 

[marinemech]

Re: 1998 Johnson 175 Ficht overheating

two thermostats top of each cylinder head<br />ficht engines have been getting better and better<br />have a tech moniter temp using a lap top computer and diagnostic program to see engine temp as ecu sees it could be a false reading have had a couple of ecu's not reading water temp properly<br />also impeller housing could be leaking exhast gases in causing overheat<br />just a thought and good luck