big temp swing, 2.4 chrome 225

[CKMATE225]

I finnaly got my temp guage hooked up, I was out running the river and at Idle the temp would climb to just over half way, as soon as I would get up on plane it would drop right down to cold, It appeares the everything is operating normally, Good WP ,(8-15psi),obviously the poppet is opening up at higher rpm.The water was cool. but does that sound normal?
I could see droping a little at higher rpm but it went right to cold 30 seconds after getting it on plane but not right down to just above C, So is it just the cold water or should I check the thomostats or something else?
Unfortunatley between all the no wake zones and the debris in the river I couldn't get much extended running time at higher RPMs to see if it would start to climb.
Any thoughts?

[sschefer]

Mine does that too. I'm thinking the spring in my poppet is weak and it's opening too soon. I suspect that at idle with the poppet opening up, the heat transfer is not happening. Mine goes from 175 at idle to 145 at WOT. Once in a while when I shut down fast my WP gauge drops to zero and stays there. If I rev the engine the pressure comes back like maybe the poppet was hung open.

[CKMATE225]

I guess it would probly be worth checkin' out and just replacing the poppet cause I have know clue how old it is or what condition it in.
But Ill tell ya this, I dont like how much it changes with that blast of cold water running though it when the poppet opens. It makes me a little worried that she will lockup or crack beacuse of the thermal expantion diferences in the block and pistons, I think I liked it better when I didn't know what the hell was going on with it.

[sschefer]

Mine takes about 1/2 mile to get back down to 145. I'm not worried about rapid cooling, I'm more afraid I'm gonna scuff pistons before I get out of the no wake zone. I know what you mean about not knowing. Mines lumpy as heck at idle so I wouldn't know if it was starting to sieze or not without the gauge telling me. I've had three boaters tell me I should take it in for a tune up. Of course, that's before I blow their doors off on the open water. O.K.. I know it's not fair running 115hp decals on my cowlings.... LOL...