swaping out heads

[Mideerslayer]

I have 2 motors,the one on the boat is a mid 70's 75hp chrysler.

The other one is a 85 85hp force(blown piston),all the parts bolt up except the ignition.

I am thinking of putting the head off of the 85 onto the 75,because it has a thermostat in it,I had to take it off due to a blown head gasket.

I am also going to put on the lower unit from the 85,because I was told it is a better cooling system and more prop option's.


I also swapped out the carb's.

Should I be ok?

 

[bashr52]

Re: swaping out heads

I just swapped a complete 85 power head onto my 75 lower unit. I took the carbs and ignition system from the 75 for the 85 as well. It runs ok, but doesn't make full RPM's or power with the smaller carbs. You may have a problem with the bigger carbs on the smaller engine, running rich and increased fuel consumption. It should run though!

 

[Mideerslayer]

Re: swaping out heads

should I stick with the 75hp carbs,they appear to be the same size?

I am trying to get the most power out of the motor

 

[huskerdaninva]

Re: swaping out heads

You may want to pull one of the fuel bowls off of one carb from each set and compare the main jet size. It should be stamped on the jet. I would stick with the carbs that were on the motor originally. My main concern would be to ensure that the main jets are all the same size. May as well give them a re-build with a good cleaning/soaking while you're messing around.