Fuel mixture after rebuild

erosenwinkel

Petty Officer 2nd Class
Joined
Apr 22, 2011
Messages
130
1985 Force 125 hp (1258x5a) I recently had this outboard rebuilt. I have run about 25 gallons of fuel out of it (35:1 ratio). Varying speeds and not opening it up for more than few seconds at a time. I was told that the ratio will probably foul the plugs, it hasn't. How many more gallons should I run through at 35:1? Then, go directly to 50:1 or go in between? If my top speed is 33 mph at 35:1, can I expect a little more speed at 50:1 (18 foot Bayliner Capri Bowrider)? Do I need to adjust or sync the carbs at all? I'm not looking for all out speed, I just want to do what is best for the life of the motor. I don't have a fancy prop, it is probably original to the boat. Idles fine, not a smoker, sounds real good (surprisingly quiet compared to others I have heard) I know I ask a lot of questions, sorry. Weekday carpenter, weekend boater, trying to learn.
Thanks, Eric
 

jerryjerry05

Supreme Mariner
Joined
May 7, 2008
Messages
18,089
Re: Fuel mixture after rebuild

Go to 50-1 Top of the Force Forum is a thread from FrankA on how to do a linc and sinc.Do that and see what happens.Make sure the buterflys in the carb are opening all the way.
Speed??? 50 or 35-1 shouldn't really make you go faster.What is the top RPM's at WOT? You need a tach to be sure.
Just for fun do a compression/spark test.
The rpms should be about 5500 at wot.Any less or more will affect the speed/performanceNow that its been broken in.
Run it like you stole it.If it's gonna go it will go no matter how you treat it.
These motors are made to run full tilt.Full speed will hurt the economy but don't be afraid to go!!!
I never run wide open cause I'm cheap.I've found 4000 to 4400 a good operating range on my motors.J.
J
 

Robert D

Petty Officer 1st Class
Joined
Feb 21, 2009
Messages
338
Re: Fuel mixture after rebuild

If it wasn't smoking a lot and fouling the plugs at 35:1, it has to have some good compression. I'd stick with 50:1 at this point. Several different schools of thought on breaking in a 2 stroke. (And for a 4 stroke as well!) 25 gallons of fuel through it, I wouldn't worry anymore, just drive the thing normal. I would avoid full speed extended runs for a while, though. (More than 3 or 4 minutes) Brief runs to 5500 rpm are best, along with varying the engine speed, & watch the temperature of course.
 
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