1982 mercury 4.5 hp

[hook&go]

Does anyne know why i cant turn engine speed on tiller handle.it seems to be stuck but all linkage seems to be fine. Is there some kind of interlock or saftey feature that prevents this from turning?

 

[racerone]

Re: 1982 mercury 4.5 hp

It has to be in forward to get full throttle I believe.

 

[hook&go]

Re: 1982 mercury 4.5 hp

It has to be in forward to get full throttle I believe.

I thought about that. I just rebuilt carb and it wont stay running so I haven't got that far yet. I appreciate the in put so when I get it idleing I don't have this issue. it has been sitting in my buddies garage for 5 years as he only used it once a year at xmas. thanks

 

[River Boy]

Re: 1982 mercury 4.5 hp

I've got a couple 4.5s. No interlock, I just went out in the shop and double checked.
The twist grip controls the advance plate only, and then a cam on the advance plate controls the carburetor butterfly through a throttle arm. That's all there is too it.

Might be just gunked up with old grease and crud from sitting for five years.
Is that throttle arm hitting the advance advance cam i properly?

You didn't take the 'arm' off from the carb did you? If you did you might better do a link and sync.

 

[hook&go]

Re: 1982 mercury 4.5 hp

i've got a couple 4.5s. No interlock, i just went out in the shop and double checked.
The twist grip controls the advance plate only, and then a cam on the advance plate controls the carburetor butterfly through a throttle arm. That's all there is too it.

Might be just gunked up with old grease and crud from sitting for five years.
Is that throttle arm hitting the advance advance cam i properly?

You didn't take the 'arm' off from the carb did you? If you did you might better do a link and sync.

i didnt touch anything there. I did spray it down with wd 40, but its very clean because he never used it. Now that youve explained the operation ill double everthing. Thank you for your help!

 

[hook&go]

Re: 1982 mercury 4.5 hp

i've got a couple 4.5s. No interlock, i just went out in the shop and double checked.
The twist grip controls the advance plate only, and then a cam on the advance plate controls the carburetor butterfly through a throttle arm. That's all there is too it.

Might be just gunked up with old grease and crud from sitting for five years.
Is that throttle arm hitting the advance advance cam i properly?

You didn't take the 'arm' off from the carb did you? If you did you might better do a link and sync.

i checked the linkage and that seems ok . I believe the problem is where the 2 gears meet. The one from tiller handle tries to move when you turn it genltly, you can see that black shaft turn upper gear. The gear that runs to the bottom of the motor seems stuck. I sprayed it with wd 40 and tried tapping it with a screw driver and hammer lightly to loosen it. I did it in neutral and forward.is that speed suppose to move in both forward and neutral. Any suggestion would be appreciated. Thanks again

 

[River Boy]

Re: 1982 mercury 4.5 hp

i checked the linkage and that seems ok . I believe the problem is where the 2 gears meet. The one from tiller handle tries to move when you turn it genltly, you can see that black shaft turn upper gear. The gear that runs to the bottom of the motor seems stuck. I sprayed it with wd 40 and tried tapping it with a screw driver and hammer lightly to loosen it. I did it in neutral and forward.is that speed suppose to move in both forward and neutral. Any suggestion would be appreciated. Thanks again

Sounds like those gear are stuck to me. Does the advance plate turn easily?

That whole twist grip throttle assembly comes apart pretty easy for cleaning as I remember. Pretty straight forward. Then reassemble with some kind of oil or light grease.
Again, the shifting mechanism has nothing to do with the throttle control on a 4.5 Merc.
They are independent of each other on that model.

WD40 ain't the best long term lubricant in my opinion. IT will turn into a gummy/varnish substance once the wet solvent dries out which will compound your problems.

 

[hook&go]

Re: 1982 mercury 4.5 hp

Sounds like those gear are stuck to me. Does the advance plate turn easily?

That whole twist grip throttle assembly comes apart pretty easy for cleaning as I remember. Pretty straight forward. Then reassemble with some kind of oil or light grease.
Again, the shifting mechanism has nothing to do with the throttle control on a 4.5 Merc.
They are independent of each other on that model.

WD40 ain't the best long term lubricant in my opinion. IT will turn into a gummy/varnish substance once the wet solvent dries out which will compound your problems.

advance plate does not move and I have been trying to loosen it without taking things apart. I haven't really sat down and devoted a lot of time to the project as im not a mechanic. im trying to fix it since parts are not really available,labor is to expensive and so are motors. I am persistent and with your knowledge ill get it eventually.

 

[hook&go]

Re: 1982 mercury 4.5 hp

I ve been working on it for awhile now and dont understand how the linkage should work. Im down to 4 bolts and 2 parts. The first one attaches to the throttle control lever in the picture with the short side and longer arm facing toward left side of motor.i cant figure where the other side attaches. The next problem iis what i believe you reffered to as an advance plate. I dont see that displayed anywhere in exploded diagram of the stator and ignition but yet it is listed as part 25? In parts list. This part was fastened to bottom of stator. I looked at a video on youtube with motor cover off and it shows this part moving ffrom left to right as engine revs up.these 2 pieces were originally connected,so with advance plate mounted under stator it could never move as shown so i guess thats why you asked if it moves freely. Obviously it couldnt the way it was.any help would certainly be appreciated as im at a loss for answers now. Thanks

 

[River Boy]

Re: 1982 mercury 4.5 hp

What's the model and serial numbers on your motor?

 

[hook&go]

Re: 1982 mercury 4.5 hp

Mercury 4.5 s/n 6105274 made in usa

 

[River Boy]

Re: 1982 mercury 4.5 hp

Mercury 4.5 s/n 6105274 made in usa

Yep, 82 USA model. I wanted to make sure it wasn't the 2 cylinder model they made for a while.

OK, at the back of the twist grip assembly there is a vertical rod. A gear is attached to the bottom of the rod. The top of the 'rod' is attached to a black plastic 'arm' THAT is attached via a 8x32 screw and nut to a flat aluminum arm.
This 'aluminum arm' is attached directly to the moveable 'advance plate'.
NOW, if you remove that 8x32 screw, the advance plate SHOULD move independently from the twist grip assembly.
That will tell you if your binding problem is in the advance plate ITSELF, OR, if there is a binding problem in the twist grip assembly ITSELF.

You see what I'm saying? Break these two assemblies apart and then you can easily see what is causing your problem. Either the twist grip or the advance plate.

 

[hook&go]

Re: 1982 mercury 4.5 hp

I think it finally came to me this afternoon. I attach the arm with bolt and wave washer.the advance plate gets fasstenedto arm through the short keyway and bolt throgh *** on stator plate. What is the bigger keyway and hole on advance plate for. At least this should allow plate and handle to move. I havent bolted it up yet but it should work, but i know there has to be a reason for the other groove and hole in plate.