prop pitch may not be right!! any help apreciated

slvrwolf1

Seaman
Joined
May 23, 2007
Messages
56
I have a 1975 75 HP evinrude on a 1973 ensign boat. Boat and motor are about 1600 pounds and I dont have a tach. I nicked my prop last year and couldnt find anyone that knew what kinda prop it was but finally this year someone told me they can tell it was a repaired prop already and there were no numbers on it but they think it is a 13 x 19 3 blade prop.

The marine shop told me the new props work the motor harder so they droped it to a 17 " pitch. I took the boat out this weekend and it had a real hard time getting on plane but once it was on plane it seemed ok.

I also had a little carb problem while out tho so I dont know if it was the new prop or the carbs. This problem happened about 4 hours after we were out. The carbs didnt want to take full throttle for some reason.
If I go to new prop size do I need to adjust throttle link or timing or anything because thats how I was able to get it going again was to let someone else drive while I played a round with the throttle link a little and adjusted timing a bit.
 

tashasdaddy

Honorary Moderator Emeritus
Joined
Nov 11, 2005
Messages
51,019
Re: prop pitch may not be right!! any help apreciated

Ethanol and fuel lines
replace all fuel line with Alcohol resistant lines. Ethanol deteriorates, the rubber lines, then they start to sluff off on the inside, going directly to the carbs. Settling to the bottom of the bowl. Contaminating the carbs high speed jets. clean a rebuild carbs, flushing fuel line before connecting to carbs.

solve the carb problem, then the prop problem.
 

slvrwolf1

Seaman
Joined
May 23, 2007
Messages
56
Re: prop pitch may not be right!! any help apreciated

thanks for your reply. I got busy with carbs when I got home and found out you were right carbs were nasty. I disassembeled them and on the bottom carb the float pin was swelled up so much the float wouldnt move and I could not get it out. I ended up having to cut the pin out with a thin knife to get the float out and push each segment of the pin out. Does anyone know why the pin would swell up?
 

ezmobee

Supreme Mariner
Joined
Mar 26, 2007
Messages
23,767
Re: prop pitch may not be right!! any help apreciated

Invest in a tach. It will help you immensely in getting your setup tuned for optimal performance.
 
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