My engine is running to cold. I put a new temp guage and sender it will only get up to 110 or so.didn't trust old one. I don't have a therostat. The hot water out of the block comes out of the water pump bypass on the intake then to my logs. Can I put a valve in the discharge line and slow the flow to bring the temp up or would it build up to much pressure? Any ideas?

Would that cause cavitation in the block and air locks?

My engine is running to cold. I put a new temp guage and sender it will only get up to 110 or so.didn't trust old one. I don't have a therostat. The hot water out of the block comes out of the water pump bypass on the intake then to my logs. Can I put a valve in the discharge line and slow the flow to bring the temp up or would it build up to much pressure? Any ideas?

Please clarify, "The hot water out of the block comes out of the water pump bypass on the intake then to my logs." Do you mean that the dump lines go to the logs or to the snails?

Assuming that you have thru-transom exhaust, the water should be plumbed from the jet, into the rear of the logs, exiting the front of the logs, into the timing cover's waterpump holes at the front of the blcok, then out the thermostat housing and into the snails.  The water is preheated in the exhaust logs before going into the engine block.  If you have a different cooling system than assumed, then please describe so that the proper info can be posted.

Installing the gate valve after the jet but before the engine can slow down the water travelling through the system and thereby allow time for it to heat up. Finding the correct setting on the gate valve takes experimentation with each engine setup.  Remember that as you close the gate valve (so as to get to the water temerature up), the temp increase becomes more sensitive the further the gate vavle is closed (restricts the water flow). Also, the engine will run cooler at speed than it  will while in a 5 mph zone, so keep this in mind when setting the running speed; eg, the gate valve is NOT a thermostat.  With my engine, for example, I run at about 160* at speed, then it climbes to 190* peak when I enter a 5 mph zone....and then the temp slowly tapers down again.  The operating temp I run my engine at is higher than most people are comfortable, so you don't need to get that close to the water's boiling point....just  giving you an idea of the temp variation. My gate valve is somewhere between 1/2-turn and 1 full turn open from closed.

LO