Volvo Inline 6 Wonbt warm Up

Hi!
I've just replaced t

Hi!
I've just replaced the thermostat on my 1976 Volvo inline 6. It is installed correctly but the engine won't warm up past 120 degrees. I was told by a marine mechanic that it's ok. Someone else told me that if it doesn't get any warmer than that it will run rich. It does seems to run rich. I thought it might be the gauge but I can put my hand on the block while it's running at idle. Is there a way to internally bypass the thermostat? While running faster the temp drops to about 100 degrees. The water pump has been changed and there is plenty of flow. This condition isn't new but I thought the new thermostat would regulate the temperature. Is it a problem? I was using the hose to run it and the water temperature was about 40 degrees. Was the water temp just too cold?
Thanks!

" Do you know what the temp ra

" Do you know what the temp rating is on the thermostat? Water coming in should not make a difference. The themostat should stay closed allowing the engine to come up to temp, when the water is at themostat temp it will then open.
I don't think it will create a problem, but engines run better at their operating temperatures. They start easier, and run cleaner.
There is no way I know of to bypass, but you can put a thermostat in with a higher temp. "

" Thanks joelt! The temp rati

" Thanks joelt! The temp rating is 130 degrees. Does this mean the normal operating is 130 degrees? According to the manual it should be fully open between 151 and 158 and close between 127 and 133. I just finished testing the old thermostat and it started to open at 135. Fully open at 155. The new thermostat reacts the same way. The thermostat must just reduce the amount of flow, not cut it off completely. According to the temp gauge, the thermostat shouldn't open at all. The engine doesn't reach 130 degrees. Dan "

" Are your gauges reading corr

" Are your gauges reading correctly? Hire a Mech.that has a temp. gun or a temp. probe to go out on seatrials with you to confirm actual engine temptures. Running a cold engine is not good. Premature wear, carbon deposits & poor economey
Is your engine raw water cooled or do you have a heatexchanger? Cold engines are a rare complant~ Would be supect of temp sender. "

" Thanks BJ! Here's the l

" Thanks BJ! Here's the latest. I'm not sure how this happened, but the timing was off. Way off. I had to advance it more than 8 degrees to bring it back to specs. The temp is now at 135 degrees and it purrs like a kitten. I only had the boat out once last year, and the year before I trashed the prop at the end of the season. I never thought to check the timing. Is it possible to knock the timing out if you hit something with the the prop? The distributor was clamped tight. Thanks for everyones help! "