TOPIC: merc 500 will not shift

i have a 1961 50 hp merc , i picked it up last summer and did not do anything to it but check spark and comp. last nite i hooked up the controls and it seems to be stuck in gear. i called the guy i got it from and quized him about it and he said he removed the lower unit to replace the water pump and decieded to sell instead, so he just put it back together. now i know there is a trick to install the lower, the problem i have is i cannot remember it. another case of CRS. lol. iam going to redo the lower anyways so i just want to know how the best way to get the shifter shaft lined up. thanks for the help. frog

drop the lower unit ....turn the shift shaft on the lower unit to make certain you can find FNR and all is well...now set the shift shaft so the prop shaft is in neutral.....set the shift lever on the lower cowl in neutral....now install the lower unit use a screw driver to help guide the water tube into the rubber gromet....you may need to rock the flywheel a bit to line up the splines

some people prefere forward gear some neutral

Have you tried shifting without the cable attached? I just mounted a '62 700 and after hooking up the cables and trying to shift it went into Forward and stuck- even after I took off the cables. Turns out the cables were out of adjustment and the throttle advanced the distributor so the cam that keeps you from shifting at high RPMs was blocking the relay cam for the shifter. After manually retarding the distributor back to its stop and adjusting the cables everything seems fine.

he removed the lower unit to replace the water pump and decieded to sell instead, so he just put it back together.

almost willing to bet

Reminds me of a mechanic I used to work with, I can still hear him say in his Belgian accent "Uh oh.... somebody's been here before."

thanks guys, iam going to pull the lower this week end if time permits. i,ll let you know what i find, i hope that the shift shaft is not frooze, but begining to wonder why he did not put the impeller in!!!! maybe found other bad parts. frog

I just went thru the same issue with the exact same motor I picked up last weekend. It was stuck in forward and I know the foot was off of it because it was missing 2 of the 3 5/8ths nuts. Here is how I have learned (the long hard way) of putting these back together and having correct shifting.

with the gearcase off(after you have checked the impeller of course) using the shift rod get it into FWD gear( ie when you spin the drive shaft clock-wise the propeller turns in the fwd direction. Turn the shift rod(probably need a pair of pliers...Counter-clockwise all the way until you hit the gear and it will move into neutral and then a very short distance after moves into reverse. (I find it sometimes really hard to have it just sit in neutral so this is why I always change it in FWD). So..if you are in N or R turn it clockwise back to where it is in F but just up against N.
Now ensure that the shift arm is in FWD and you should be good to go. Sometimes the upper shift arm will not line up to easily slide over the lower shift lever. With these older Mercs I found that you can wiggle the shift arm where it is outside the exhaust housing before it disappears into the lower to line it up.

Good luck with your motor.

I have rebuilt the carbs and cleaned and set the points etc and I now have a leak in the lower carb inlet filter cover and the motor is kicking with pre-mix in the cyls but it wont run.

Oh the joy of these old girls.

also when you catch the 2 front nuts watch the top of the shift shaft under the bottom carb it can shift up so use a long screwdriver and a hammer to tap it down helps with allignmet also. when finished tightening it up tap it down again.

thank you dave and barnfinder, i was going to look at it last wk end but had a hugh honey do list waiting, but will let you all know how i did and ask for more help. thanks frog