Carb issues...72 chrysler 45hp

[Fuss188]

I have been having a problem with the boat getting on plane. Doesnt seem like the motor has enough power. Theres a screw on the very front of the carb, right above the bore. I seem to get more rpms when I turn that screw all the way closed. Is this an air mixture screw? If so shouldnt the engine die when I close that screw all the way? I pulled the screw out and it looks like there should be an o-ring on it. Should there be? Any suggestions or ideas on how to make this old engine perform better would be greatly appreciated. Thanks.

 

[jerryjerry05]

Re: Carb issues...72 chrysler 45hp

No o-ring on the screw.Screws taper should be smooth.It should be set at 1 and 1/8 turn out.Then adjust from there.
It should turn off if screwed in all the way.
Do a compression/spark test.Then check the fuel system.
Ethanol is messing up a lot of motors.It's delaminating the inside of older hoses causing clogs in the carbs and fuel filter.Check for soft hoses and junk in the filter on the motor.Check the diaphram.
Performance!!! Good compression a must.Then timing set right.
Then a tach is necessary to make sure the motor is operating at the right RPM. 5300-5500rpm at WOT. If your not operating around that you will use more gas.Overloading a small boat will bring the rpm's down too.
3 fatso's and 2 kids 3 dogs and the 2 cases of beer might be too much for a 45.Don't forget gas and the wife.J