Changing t-stats in a 225 4stroke

[gwseafarer]

I'm changing the thernostats in my 2003 f225 Yamaha 4 stroke. They are tough to get at. the starboard side looks easiest. The port...well thats another story. I would like to know if anyone has any tips on making this an easy change. Whats up with no gasket? Should I use gasket compound or permatex? Thank you in advance....mezman

 

[rodbolt]

Re: Changing t-stats in a 225 4stroke

the easist way on the stbd side is to remove the flywheel cover,remove the 2 10mm hex bolts holding the electrical/fuel line holder in place, remove one of the TPS screws(philiips head, reposition the alarm wires then you can access the 2 10mm hex t-stat bolts, port side I remove the ISC assy.<br /> the pressure control valve is about as much fun to get to.<br /> the t-stats take me about 45 min to change on that motor.<br />unless,of course, ya drop one of the screws behind the intake.<br /> next time your at your yamaha dealer have them run the primary ID, there may be as many as 3 recall bullitens and you want to insure they have been done.

 

[gwseafarer]

Re: Changing t-stats in a 225 4stroke

thank you for the reply rodbolt. you're talking to a rookie here. does TPS stand for THROTTLE POSITION SENSOR? you're talking about the screw that holds the hose in position, right? as for the port what is the ISC assy? should I change the pressure control valve? as far as recalls go the dealer updated whatever they had to last spring.

 

[rodbolt]

Re: Changing t-stats in a 225 4stroke

yes, the clips that hold some of the fuel lines in place need to be moved, TPS is throttle position sensor and ISC is idle stabilization control, also known as IAC Idle Air Control to the rest of the world. the manual says to clean/inspect the water pressure control valve every 200 hours or annually. not real sure why because its all one unit. at least its not quite as expensive as a t-stat.

 

[gwseafarer]

Re: Changing t-stats in a 225 4stroke

thanx again rodbolt. I just finished the starboard side and it was not that bad. I did drop the old t-stat behind the throttles and it was a challenge to get it up and out of there. <br /> Is the ICS on top of the throttle bodies?<br />Is it held in place with 3 - 10mm screws and has a round sensor with pink wires that clip to it? <br />Also has 3 hoses attached? <br />I just want to make sure that I don't screw up anything.

 

[gwseafarer]

Re: Changing t-stats in a 225 4stroke

Rodbolt, thanx for the info. I just finished the t-stats change. You were a great help. It's people like you that make this a great forum. Keep up the good work!!!