Thread: Yamaha f50 to 60 conversion

Never tried it, mine is carbed instead of injected or I would have. Watched the videos and read a bunch on it. Some say you should have ECM reprogrammed. But if you take the baffle out and run it the ECM will make most of the needed adjustments on it's on. Just takes a little run time. I could not find anything that lead me to believe it would harm the motor in any way.

You can increase RPMs on any motor by changing the prop. However, if you get the RPMs higher than the recommended WOT RPMs then you are most likely to loose power and efficiency. What is your RPMs at WOT now and what is recommended?

Only getting 4500 rpm now. I do need to get a better prop. My prop is a alumni prop 15pitch. Which is alittle dinged up but I never got over 5000 when it was brand new. My boat is an xpress explorer 170 series boat with 50hp Yamaha 4 stroke

#1 you are over propped for that boat. If you increased your motor 10 HP you could carry a little more prop but don't know you could get full potential out of the 15 especially Aluminumn. My setup is a 17.5 Wareagle stick steer pretty close to the same weight as yours and not as performance oriented as your hull. I run a stainless 13, motor up one notch on transom. I can lift bow completely out of the water, run 32 on GPS and turn 5800 to 6000 rpm's which is just a little high for that motor. I really don't know what pitch props are avaliable for that motor but looks like you need something in the 13-14 range.i would definatley recommend stainless and raise motor if it's sitting flat on transom. Won't cost you a thing to remove that baffle and just see what if any gain you get. Your certain lye running at the bottom end of the RPM range.

I agree with Cray on changing prop pitch.

If ur engine is around the 2008 or so age don't pull the restrictor out. The engine uses speed density to determine fuel and spark mapping. It looks at only throttle position sensor, temp sensor and rpms to look up fuel trim and spark advance from a hardcoated chart. It has no oxygen sensor or mass airflow sensor so cannot correct for he increased air flow. Too much air equals lean mixture whci increases combustion chamber temp. On a good hot day with it rnning hard one of the pistons will develop a hotspot and a hole will develop. Folks do it and get by but it is still an iffy thing to do. I have the same motor but is Mercury branded. If I do it I will have the ecu flashed with the 60 hp mapping. Just trying to be helpful!
Greg

Motor is 2012 model. Figured I would try it an see. I did get about 200 to. 300 rpms more. Gain about 5 mph. Probably going to get some different props an put the restricter plate back on. (Me getting older an wiser) Don't want to risk hurting anything in the long run but was wanting to see what other ppl thought an I couldn't resist not trying it. It's going to be hard to put it back on though. Love the mid range acceleration.