TOPIC: 71 7.5hp question..

hey guys looking to see if anyone out there may be able to help me out... im fixing up a 71 7.5hp for my nephew.. and just found out i dont have the right fuel tank fitting for this motor.. the tank connector is smaller than the ones i have.. and the only thing i've seen so far is a little pricey just for the fitting.. seems like these older motors have their own special fitting...
think i'll also try to mount a newer fitting inside the cover and maybe just upgrade it so he never runs into this kind of trouble also??

and i also im searching for a fuel pump cover for the same motor.. the outter plastic cover is cracked..(now) just figured i'd ask in here..
the cover is NLA ..Part Number
54066... IF not it looks like i may end up having to get another complete pump.. and i just rebuilt this and cracked it putting the fitting back in.. just my luck, right...

Go ahead and simple change out the fitting. Done it a few motors. Can't help ya on the rest

call me I might have a fuel pump.
1 914 310 7086

called you and left a message...

thank you dave.. just sent....

so far so good.. i've been able to find everything we need..
so this morning i dropped the lower unit to measure the water pump impeller.. well i come to find out the shift shaft is rusted up pretty good.. so i found a few shafts available.. and was just wondering how hard they are to replace.. they look to be just splined into the bottom shift gear... can i swap this without tearing the whole gear case apart??? they only lign up 1 way in the bottom gear... so if i pulled out the shift shaft seal. will the shaft just pull out???????

Don't simply pull the shift shaft. There is an E-clip on the shaft that will fall into the gear case and then may require full disassembly to locate & remove it.

1) Clamp the gear case in a vise with the driveshaft pointing straight up. (90 degrees to the floor of the shop)

2) Shift into Forward Gear. This takes the pre-load off the shift cam in the gear case.

3) remove the mall set-screw with a square top.

4) gently lift the shift shaft bushing assembly out, while holding the shift shaft down so it won't come out with the bushing.
Heat and a set of pliers may be needed to get the shift shaft bushing moving.

5) Now gently rotate the shift shaft back-n-forth in the Forward Gear area to confirm the pre-load is released.

6) Mark or make mental note of where the shift shaft's missing spline at the top of the shift shaft is facing.

7) lift the shift shaft straight up and out.

doc F

thanks Doc..
after a little heat i got my shift shaft bushing and shaft out without any issues.. but NOW

i'm thinking im going crazy here looking for this part..

to me THIS looks like a short shaft motor... but when i looked and found the part.. i had the guy measure it first and his came up around 11 3/4 inches...end to end..i'm thinking he has the wrong part number listed for his part...

now i measured my shift shaft and its 26 inches. end to end.. am i crazy to think there's no way a long shaft motor is 14 1/4 inches longer ?????

no there are different length shafts for them depends on the year.

the reason its driving me nuts.. is im finding the same part number in different sizes.. so either im crazy, mercurys crazy or the people listing these parts is crazy... LOL

ok a little update.. we finished up this motor.. it was running great... he took out this past weekend to get started working on his duck blind...
well the motor starts to run rough and dropped a cyl... he brings it back over and it has no spark on bottom cyl.. so i swapped out another set of coils and still no go..
so i popped the flywheel off again.. and rechecked the points.. everything looks good.. gap set at .020
but still no spark on bottom cyl...
so i decided to swap the new points around and now i have no spark on top cyl... can someone explain how a brand new set of points can be dead?
i pulled them out again and cleaned the contacts.. but they didnt look bad to start with.. and still no go.. so just for the hell of it i threw in an old burnt set.. and i have spark??????
i dont get it?

If is not the points, it is probably the white insulator that joins to them. They are notorious for cracking and even a small hairline crack will render them useless. Inspect carefully for cracks with a magnifying glass, or better yet put in a new set. They will allow the points to short to ground, killing the spark, a VERY common fault on this engine.

already done that when i serviced the whole motor for him.. every thing was replaced... new points.. new insulators. new wires from points to coils..i pulled the pivot half of the points out ( the spring side ).. and installed a burnt one.. and i have spark... so i swapped back in the new half of the set of points.. and no spark.. thats what has me so confused... because these are brand new points... with less than 4 hours of run time on them..

Just when I thought "Murphy" only visited my little Mercury Magic Shoppe,...I see he is alive and well and also harassing other fine guys making efforts to keep old Mercs alive.
I will have a shot of TC-W3 before I go to bed tonight and send positive thoughts your way!!!

doc F

thanks doc... i have a crazy theory and idea in my head,i want to try out today.. i'll let you know if im right and it works..

Interesting I would have guessed that there was something different between the two sets of points but when you said that they had four hours on them the new ones ran. It will be interesting to hear why you have spark with the burnt half set of points and not with the new half. Baffling. Hope you find the problem.

could be a defect in the bad set check with a meter. just my thoughts. had a loose contact once.

well i tested my theory... i put a layer of high voltage shrink wrap over the spring side of the points.. as far down as i could go all the way up to the insulator where they bolt on..it worked
so i pulled the other set off and did the same thing just for good measure....
im back to fantastic spark.. and fired right up first pull...