replacing thermostats

[seapro21]

going to do the water pump on my 2001 ox66 200hp for the first time. i have detailed instructions with pics on how to but nothing about the thermo stats.
last time they were replaced was 3 seasons ago along with the water pump.do they need replacing ?
i found some instructions/pics on the how to, but how often should they be replaced?

[jnicosia]

I would change them for sure, pretty easy to do just do a search on you tube.. I changed mine last season and they were gunked up a little 2003 hpdi.. I am gonna change mine every season I think. since I put about 300 hrs/season

[rodbolt17]

I am new to this forum however if you wish I can post a step by step bolt by bolt instruction including some information thats not in the service manual

[99yam40]

I am new to this forum however if you wish I can post a step by step bolt by bolt instruction including some information thats not in the service manual

Welcome to to the forum Rodbolt, it suprized me this morning when I saw your name on this site, good to have a Yamaha master tech on board. Things must be slowing down there and you have more time on your hands this time of year to allow you to join another forum and give some good advice.

I am sure your bolt by bolt instruction including some information that is not in the service manual would be appreciated by all, if you have the time.

[rodbolt17]

99yam40, not really .
however all things change.
when I get some time I will hunt down or simply retype the instructions on 2 stroke V model water pump,t-stat and pressure control valve maint.
4 stroke V models are a bit different,except the water pump.