First too hot then too cold?

[Backyardhockey]

Merc 305 V8 with Alpha 1. First start of year. I do the winterizing. Starts fine on muffs but gets to 200+ within 3 minutes. Shut it down. Water in block and both those black iron things next to the valve covers. Restart, with the hose that brings water into the engine disconnected just past the PS cooler. Water is gushing out of that hose. Reconnect hose after 2 seconds and run engine at 1000 rpms for 15 minutes and temp never goes over 135! Engine is normally at 175 or so. Freshwater only. Bad T stat?

If T stat any problem using one from auto store? Recommended T stat temp? Gasket or some kind of goo? Thanx.

 

[Bondo]

Re: First too hot then too cold?

Ayuh,... Auto T-Stats are Too Hot...
Get yourself a 160? T-Stat,+ the Proper Gaskets...

 

[Backyardhockey]

Re: First too hot then too cold?

Thanks, I'm going to put a tstat in this weekend. I've started it a couple times this week. Same deal, stays at 135. The top hoses from the tsat are cold. Does that say anything? Also, somebody told me that if there is a lack of water the temp guage doesn't read a real temp. Is that true? Makes sense, but it seems like the temp sender should be in a better spot. I will look at an IR reader this weekend.

 

[Bondo]

Re: First too hot then too cold?

I've started it a couple times this week. Same deal, stays at 135.

Ayuh,... I don't see a problem with That,... Pretty normal for on the Hose...

In the water, under Load,... You should see 140? to 150? with a 140? T-Stat...
160? to 170? with a 160? T-Stat...

Lack of water, the Temp Sender sees Nothing...
Using the Wrong Gaskets on the T-Stat housing will cause a failure of the Temp Sender as well...

 

[Backyardhockey]

Re: First too hot then too cold?

Thanxs again Bond-o. Well, the Tstat is going to stay because I couldn't get it out! Seems to be epoxyed in or something. I does work, so I didnt go nuts on it. Once I couldn't pry it out I started it up and let it run. Still at 135. Thought maybe it would come out after getting warmed up, but no dice. It was open, and I noticed all hoses would get warm when I put rpms to 1500. Any trick to get these out? I ended up using some SAP "gasket in a tube". I'll get a real gasket very soon.

Also, while on muffs, how hot should the exhaust manifolds and risers get? Starbord manifold seems very hot. BTW I see very little water going out of the prop, if that means anything.