1969 Mercury 35 hp

[swimmin' for shore]

I had a 1969 mercury 35 hp all but given to me the other day. I tested the compression at 145 on each cylinder, put it on a stand, and wiped down the motor. Everything looks okay, but I started to experience a few issues with it, and I want to see if I can try to solve at least some of them here before I spend any money with a mechanic. I'm going to take these in order of what I at least think is most important.
1. The outboard won't shift smoothly. I took the cables off, and they're a little old, but they're free. I got in there with a little WD 40 and got the shift rod to move back and forth a little more freely, but when I put the cable on, it shifts really, really hard. I can see that the lower unit was cracked and welded, but the guy said he had run it for another year before giving it to me, and that the weld repair had worked fine. It's leaking a little bit of oil though, so I'm wondering if the whole repair wasn't quite as good as he seemed to think. In any case, if we can figure out the shifting and I can verify that the lower unit is working okay and that I can repair this, we'll be ready to move to the lack of spark. Thanks in advance.

 

[swimmin' for shore]

Re: 1969 Mercury 35 hp

any ideas on this shifting issue? Bad lower unit?

 

[corm]

Re: 1969 Mercury 35 hp

Hi,

It could be as simple as the reverse lock cam not having any lube on it.
You probably will have to drop the LU to grease it. If it has a nylon reverse lock cam put in a metal one.
Also on some older control boxes the cam needs some lube on it too.
The grease gets dry and when it is loaded up shifting they get stiff.

 

[swimmin' for shore]

Re: 1969 Mercury 35 hp

Alright. I took the prop off tonight and the lower unit is destroyed on the inside. The cast aluminum (I believe it's cast aluminum) between the prop shaft and the body of the unit is cracked in multiple places. I dropped the lower unit and that freed up the shift rod, which now moves freely. I'm searching for a lower unit to replace it with. I found one from a 1964 model. the length from the bottom of the skeg to the top of the shaft is the same. Before I spend some money on this, can anyone verify that it will fit my 1969 model?

 

[Laddies]

Re: 1969 Mercury 35 hp

Yes it will fit

 

[swimmin' for shore]

Re: 1969 Mercury 35 hp

THANK YOU THANK YOU THANK YOU. After I buy that, we can deal with the next issue, which is spark. If someone wants to chime in on what to look at, I'm getting it to turn over and it has 145 psi on each cylinder, but no spark. I checked the connections, and they're all clean enough. Pull the flywheel?

 

[Laddies]

Re: 1969 Mercury 35 hp

Your engine is a standard magneto system with 2 sets of points, condensers and coils under the flywheel and parts can be bought most any place so that should not be a problem.

 

[swimmin' for shore]

Re: 1969 Mercury 35 hp

Ok. thanks for the help so far. I pulled the flywheel last night and cleaned up the points a little. They weren't in that bad of shape, but they seemed to be really, really narrowly gapped. I regapped them to .020, which was marked on the motor, and closed it back up. Checked the spark, fired the engine with a little bit of lubricated starting fluid, and it fires right over. I know the compression is good already, so I'm just waiting for the lower unit, which I won on ebay last night for a pretty good price. If anything else comes up, I'll continue it with this post, but I really appreciate the help. SFS

 

[swimmin' for shore]

Re: 1969 Mercury 35 hp

Alright. Time to bring this back up. This motor is breaking my heart. I got the lower unit in from ebay and put it on. I'd kept the old lower unit exactly as it was so that I could put the new one back together in the same way. Everything went in like it was before, and I put it together. The motor started right up, which is great since I thought a week ago that it might be a parts motor. It idles fairly smoothly, but then quit. I discovered shot fuel hoses, which I can fix on my own so I don't want to ask about. I'm tearing into that tonight.
However, I'm also finding that the motor starts in fwd and stays in fwd. It shifts by the controls and the arm moves back and forth freely, but it stays in fwd. I took it back apart and tried to reason with it, made sure everything looked right, and then put it back together. Same thing.
I looked up the following parts diagram to see what it should look like:
http://www.crowleymarine.com/mercury_parts/435/16.cfm

According to that diagram, part 41 (Bushing Assy) is there and down all the way. However, parts 42 and 43 are missing. I'll order those parts, but I want to verify that this should be enough to keep it from shifting in and out of fwd gears. Is there anything else I should do to troubleshoot this to make sure that everything else is working correctly prior to buying parts 42 and 43? If there any reason why those parts should be missing, aside from human error (ie...do they corrode and break or anything)?

 

[corm]

Re: 1969 Mercury 35 hp

HI,

The seal and the protectant washer will not effect your shifting on land.
It will let water into your LU while you are on the water which is a very bad thing. They do not come out easy so it is more likely someone removed them and did not replace them. It is my belief that your shift shaft was not in the correct position when you installed the LU on to the mid section. When you turn the shift shaft around you will feel a detent as you come into neutral. At this position the prop will spin and the drive shat will not turn. If you have not moved the drive shaft you can put it back together in neutral. Make sure you have the engine shifted int neutral too. Double check the spline position on both the LU and Mid Housing to make sure they will mate up. If the Drive shaft has moved since it was off assememble the project in forward gear. Shift the engine into F gear and turn the LU shift shaft so you just have F gear. At that time the the two pegs on part 44 will be aligning with one of your LU mounting studs. Again double check the spline alignment and slide it in. The Drive shaft spline can be alinged by turning the prop counter clockwise for engaugement. The shift shaft can be tweaked by using the shift arm either on the engine or the control box if need be. Remember to put a little grease on the reverse lock cam ramps (#44) and if #45 falls down a lot stick it in with some grease on the tabs so it holds in the mid housing.

 

[swimmin' for shore]

Re: 1969 Mercury 35 hp

I appreciate the help, but this just isn't getting it. I can put piece number 38 down the hole, but it just free spins. It's not catching anything at all. I tried locking it in place with the bushing, but it doesn't make a difference. Seems like I'm missing something or pice 45 just isn't catching down there in the gears like it's supposed to. No matter how I spin that, the prop will spin forward, but not to reverse. If I'm not missing something that you can still identify, I think I'm going to bite the bullet and just take it in to have it diagnosed. I may have just bought a dud lower unit on ebay and have got caught with it, unfortunately. The worst of it is that I've gone through everything else and I've got a nice running mercury sitting in the garage, but I can't put it to use.

 

[corm]

Re: 1969 Mercury 35 hp

Hi,

Bummer, #38 should be held in place by #39 and should not come out.
It goes into the shift cam (#55) in the bottom of the lower unit. The shift cam has been displaced by the spring tension of the shift pin (#56) that goes into the end of the propshaft (#66). You will have to pull the propshaft assembly out to get it coupled up again. Otherwise you will only have F gear. This requires a Merc special tool to remove the nut (#77). So you may have to go see a boat shop unless you want to try to make a tool or buy one.

parts diagram
http://www.crowleymarine.com/mercury_parts/435/17.cfm

 

[coolguy147]

Re: 1969 Mercury 35 hp

believe thats the spanner wrench?

 

[swimmin' for shore]

Re: 1969 Mercury 35 hp

Yeah, he's talking about a kind of spanner wrench. Thank you guys for the help. I'm not going to take it apart myself, but I'll see if I can't find a mechanic in the area. I can usually get my prices dropped by having the lower unit down already, and being able to identify the problem beforehand. At least it helps, although I wish we'd just been able to get it. Anyway, thanks again for the help and I'll add to this as soon as I can get it to the mechanic and wrapped up. SFS

 

[swimmin' for shore]

Re: 1969 Mercury 35 hp

I've struggled back and forth with this, but I want to ebay for another lower unit. I think the one I bought is toast or isn't working for whatever reason. Can anyone help me with what serial numbers of lower unit I can look for? I'm having a really hard time figuring out what models will fit it. Thanks. -SFS

 

[swimmin' for shore]

Re: 1969 Mercury 35 hp

I gotta bump this back up. I may have found another lower unit. Can anyone please tell me how you cross-reference this to figure out what years of 35 hp outboards will fit my 1969? I've tried for days and I'm getting nowhere. I don't want someone to always tell me all the answers. I'd like to know how to find them so I can help others, too. Thanks again, as always.

 

[turtles11756]

Re: 1969 Mercury 35 hp

a parts list for your model is the first thing you need .take your time get the motor running right ,pumping water and the correct LU will show up somewhere , e-bay ,craigslist or a salvage yard. you might find the whole motor for the same price. www.oldmercs.com and vintageoutboard.com