[rcheshire]

I recently bought an older grady white with known engine problems. The previous owner had a local marina diagnosis it as a shift shaft that needed to be replaced. The owner said it would not go into reverse. I can rotate the shift linkage under the carbs and clearly feel a click for forward/neutral/reverse. The prop spins freely in neutral and is solid for froward and reverse. I've read the threads on the problems with these motors needing shift shafts because OEM was not stainless. I intend to have my Honda 9.9 as a kicker on this boat at all times and would like to get a year or two out of the Yamaha before I repower. Right now the engine has some wires and fuel lines as disconnected as well as the control cables. It looks like they had started to remove the power head and broke off one bolt. The owner told them to stop, probably when he got the labor estimate. I've also read the threads on power head removal and broken bolts. I'm probably capable but not sure if I'm willing to take on that kind of project.
Thanks for your help.
Rob

[rcheshire]

I guess it would help to ask a question. Is it possible the original diagnosis is wrong? Would it make sense to put the wires, fuel lines, control cables back together and see if I can adjust the shift control to allow full movement of the lever?

Maybe the mechanic pulled the lower unit and recommended the shaft needed to be changed out. Seems like it is working now. Any suggestions?
Thanks,
Rob

[BruceAML]

First step is to get a genuine Yamaha Service Manual for this motor. Second step is put things back where they belong. If you go to the Yamaha factory web site you can look up and print the parts catalog for your motor. Almost every part is available for your motor. You cannot buy parts directly from Yamaha.
http://www.yamaha-motor.com/outboard/parts/home.aspx

[Pez Vela]

I've been through this with my 1987 Yamaha 150's so I know whereof I speak. The shaft you speak of becomes narrowed in one spot due to corrosion where it is exposed. You should be able to see this. The shaft loses the torsional strength required to shift the gears and the shaft itself twists due to its deteriorated condition. The only way to fix it is to replace it, which requires pulling the powerhead. Encountering frozen bolts is the norm and the repair thus becomes exceedingly expensive. If you do the disassembly yourself you can obviously save some money. If you know you're going to repower anyway, I'd STRONGLY recommend simply moving up your schedule on that and forgetting the repair. You'll be very happy with that decision in the long run. You will absolutely love your new Yamaha 4 stroke.

[rcheshire]

Thank you both for you replies. I am going to drop the lower unit in a couple weeks and probably verify that the shaft is skinny enough to twist as you described. I'll probably put the engine back together just to make sure it runs. Then I'll have a tough decision to make.
Thanks again,
Rob

[Monkey Butler]

I am in the middle of this same project on my 1986 V6 Special. I have everything taken apart and I am working on removing a couple of broken fasteners before I order my parts and begin reassembly.

First off, you will hear a click and feel the shifter index even if the shaft is broken. There is a spring loaded ball detent in the that acts on the top of the shifter, you can see it in this pic.



Second, here is what the shaft looks like when it is out.



and here is a closeup of the area that will rot out first.



It turns out that mine was not too far gone. Pulling the lower unit does notjing to give you a better look at the shaft but you can get a glimpse of the problem area by looking for it right around where the lower motor mounts bolt up to the leg. There is a small opening there where you can see part of the shaft. If you just want a couple of years then there was a fix posted on another board where a guy epoxied on a piece of SS tube to repair a broken shaft. Now, this does require that your shaft must already be in two pieces first.

If you want to do the teardown and replace the shaft I have pictures and details if you're interested.

Steve P.

[blackbox]

"out side of the box" shift shaft jobs. you can replace the shift rod with out removing the power head. i have done this years ago with mercs, and if you have a welder or a friend that can weld, you can fix your yam.
step#1 disconect your battery and remove carbs and duct-tape intake closed. #2 remove the lower unit. #3 grind off the weld on the top of the old shift rod and pull it out the bottom. #4 scratch a referance mark on the new shift rod so you can line it up after instalation.#5 grind the weld off the new rod and disasemble(do not lose your referance mark you made earlyer)#6 instal rod and weld in place.#7 instale carbs and lower unit. you have nuthing to lose if thr power head will not come off!