35HP Mercury - Swivel Bracket Advice Needed

[Stefan Schmitt]

After getting my 35HP mercury on a stand, today I went about having a closer look at it.<br /><br />Two things I noticed:<br />a) Someone tried to pry the lower end loose and it appears they didn't succeed (They never bothered putting the nuts back on the bolts, so it just hangs there w/a 1/4" gap. There is a pry mark on one side of the lower end, nothing big though. I tried myself gently at it, but no luck. - Any tips on loosening that?<br /><br />b) I noticed that the two upper swivel bracket bolts holding the motor to the mounting bracket are severely corroded to the degree that screwing isn't possible anymore. One side is just a clump of rust. The lower ones are in good shape, i.e. no corrosion.<br />I think that the swivel bracket itself, although corroded still can be rescued, it's the bolts and the possible weakness here that worries me.<br />How do I go about replacing those bolts? (P.S. I've even thought of just grinding down to the metal and spot welding it)<br /><br />Here's a pic with some arrows to the area I'm talking about:<br />

 

[alcan]

Re: 35HP Mercury - Swivel Bracket Advice Needed

Hi Dr Bones<br />Have you checked the compression on this motor? Does this motor turn? The swivel bracket is stuck. It may be loosened by heating the barrel with a propane torch, maybe two torches. How ever when this is done the problem seems to reoccur more easily. If this seems to be basicly a good motor I suggest that you pull the power head and the l/u. Then remove the exhaust housing from the swivel bracket. This will allow you to disassemble the swivel. There is just old nasty greese and a small amount of corrosion in there. Once cleaned and regreesed you should have no futher problems in this area provided proper maint is followed. As for those rusty nuts this is very common for Mercs and most other makes as well, in this area. Most of the time there not as bad as they look. They are ny-lock nuts, so the threads under them will be fine. Since your going to do work in this area anyway just remove them and replace. You should have a manual to help guide you with this work. The good news to all this is that tearing down you motor this far will pretty much force you into servicing everything. Hopefully you will not need to overhaul the powerhead or the l/u.

 

[jollymon]

Re: 35HP Mercury - Swivel Bracket Advice Needed

Dr Bones,<br /><br />I can address your first concern. Not only do you have the two bolts on the side, there is a third nut. Remove the trim tab/Zinc. then from under the area the trim tab sits is the third nut. Remove this and the lower unit should come off. When you are undoing the nut it may spin the bolt as well as the nut. That is OK, just keep removing it, It is a stud. With mine the stud came out instead of the nut coming off.<br /><br />I sent my lower unit to my mechanic, I could not remove the drain plug for the lower unit oil. While he had it I asked him to leak check it. I am glad I did, there was water in the oil, and the seal around the shifter shaft is leaking. He is not sure how he is going to remove and replace because of the corrosion. He thinks the lower unit is still ok, just needs time to remove seal. <br /><br />good luck!

 

[Stefan Schmitt]

Re: 35HP Mercury - Swivel Bracket Advice Needed

OK Folks...thanks for the tips! - Jollymon, there is no trim tab on mine, or rather: it's gone and the bolts in there are also w/o nuts. So, it should come off, but it still hangs. Now, do I need to shift it into some gear (fwd or back) in order to get it off?<br /><br />Here are some pics of what I'm talking about<br /><br />

<br /><br />

<br />I assume that is a lube hole there (there's another one without the slot on the other side). Does it require a plug or is it open like that?<br /><br />Also: Here are some pics of the corrosion going on with the upper bolts of the swivel bracket:<br />

<br /><br />

<br /><br />So, what do you think I should do about that?

 

[alcan]

Re: 35HP Mercury - Swivel Bracket Advice Needed

Unless your going to disassemble the swivel, or remove the exhaust housing, you do not need to do anything. Maybe a little wire brush and paint. Your corrosion your worried about is superfacial. The only time you need to be concernd about this is if the motor mounts are broken. These areas top and bottom are the rubber motor mounts ( isolation system). If you can't stand to look at this little bit-o-rust, heat the nuts up a little and turn them off. You may need a special scocket sold a Sears or maybe a cold chizel and tap them off. To remove your L/U you may need to be a bit more agressive. There have been volumes written about the tricks of this procedure on this board. Do a search of the archives and see what you can come up with.

 

[Stefan Schmitt]

Re: 35HP Mercury - Swivel Bracket Advice Needed

Thanks Alcan! I did a search and read up on it. Appears that this is a fairly common problem with l/u's on this engine.<br /><br />After that I went back out to the engine and stuffed a plastic tie wrap through that little hole in the l/u... and it came right up through where the shaft going throught the swivel bracket comes through to the lower unit. There is quite a bit of rust in there as I could tell as it kept popping out while running the tie wrap through there.<br /><br />Is that supposed to happen? I mean is the tie wrap to come up through there that easily? This shaft, is that the drive shaft? Looks a little flimsy to me, but it goes through the swivel bracket and up into the cowl.<br /><br />Here's another pic:<br />

<br /><br />Anyone want to diagnose this?

 

[alcan]

Re: 35HP Mercury - Swivel Bracket Advice Needed

I am thinking that thee hole your concerned with is a drain hole. It should be clear. The flimsy shaft you describe is the shift shaft. It has a slip-together, splined coupling. It should slide apart when the L/U is droped. I don't know is your drive shaft splines ar stuck or not. Maybe your L/U is just stuck up on the rubber exhaust gasket. You never did answer any of my questions as to the basic condition of this unit. Never judge a motor by looks. Outboards can look great and not be worth nothing, They can also look like the ****ens cosmeticly but turn out to be very good dependable runners. A little paint and polish will go a long way for an ugly duck. All the shine in the world won't help a lost cause.

 

[Stefan Schmitt]

Re: 35HP Mercury - Swivel Bracket Advice Needed

OK, to answer your questions: I've shifted into gear and tried turning the prop with no luck. I haven't measured compression and the swivel bracket moves just fine, it's just those bolts that are corroded. I got the engine for free with the statement that it didn't run a week after someone had used it in saltwater and not flushed it..and the marine mechanic's estimate was exorbitant.<br /><br />The engine under the cowling looks showroom quality, i.e. no corrosion whatsoever, paint intact on engine block, no oil leaks anywhere.<br /><br />Right now, I'm waiting on my manual to arrive. So, I haven't messed much with the engine yet. I just figured, I might as well drop the l/u since I'd have to get the missing nuts to those bolts anyways.<br /><br />The pry mark on the l/u does indicate though that the marine mechanic it was at tried to get it off. He probably figured that it was rusted tight, which might be true, and gave up. My fear is that where you see the tie wrap coming through is where there are supposed to be some seals and water got into the l/u, thus the rust in it. One way or another, I would think I need to look into that.

 

[jollymon]

Re: 35HP Mercury - Swivel Bracket Advice Needed

Dr Bones<br /><br />In total there are four bolts to remove to get this lower unit off. the two in the top that your photo's show and two underneath. <br /><br />As far as waiting for the manual, if you have a fax number, e-mail it to me and I can fax you the needed pages from the factory manual. My merc dealer sold me an old one cheap. Way better than Clymer or Seloc. It is just for that motor.<br /><br />I am not sure about the holes you are describing as my l/u is still in the shop. (it still has the mecanic stumped as how to get the shift shaft out because oif the corrosion.<br /><br />The good news is, he said that finding used l/u for that motor is easy, and only about $500 for one. <br /> njscuiba@comcast.net

 

[Stefan Schmitt]

Re: 35HP Mercury - Swivel Bracket Advice Needed

Jollymon. Thanks a lot, that would be a great help. For some reason though your email isn't working, i.e. I get it bounced back with:<br />

The following recipient(s) could not be reached:<br /> 'njscuiba@comcast.net' on 1/14/2004 10:23 AM<br /> The recipient name is not recognized<br />

 

[andrewkafp]

Re: 35HP Mercury - Swivel Bracket Advice Needed

Doc<br /><br />Keep the pics coming... <br />There is a demand on iboats for good teardown pics... <br />BTW It looks like someone has had a go a re-painting that L/U. I Don't see the familiar green zinc primer, And the cracking looks to be bad painting rather than war wounds. I recently took mine right back to alloy and re-primed and painted.

 

[jollymon]

Re: 35HP Mercury - Swivel Bracket Advice Needed

Dr Bones,<br /><br />typo in the email address it should be njscuba@comcast.net. I will have the manual with at work tommorrow, (thursday) and I do check e-mail from work.

 

[Stefan Schmitt]

Re: 35HP Mercury - Swivel Bracket Advice Needed

I'll keep the pics coming - Believe me Without y'alls help I'd be dead in the water!<br /><br />Now, progress report: Yesterday, I went ahead and took the upper cowling off (lo and behold, there is a lever for that!) and turned the flywheel. It turned over w/o too much effort. I put the engine into gear and turned again...the prop turns with it! This worked both in forward and reverse. Now, I didn't take the sparkplugs off, due to the fact that they aren't 5/8 size (the only spark plug socket I have)...but it turned over nevertheless.<br /><br />At this point, I'm considering blowing the lower unit out with some air, check and change the l/u oil and bolt it back on. It appears from the above tests that the gears in the l/u are fine, as well as the engine, i.e. it turns over. <br /><br />My next step would be to get the missing nuts, bolt the l/u tight, get a battery, hook up my fuel tank w/50:1 mixture...and see what happens then. Could be that after all, the problem w/the engine is electrical or something?<br /><br />Any comments/suggestions on my next step?

 

[jollymon]

Re: 35HP Mercury - Swivel Bracket Advice Needed

Dr Bones,<br /><br />I would agree with just bolting it back together just to test it, BUT I would not use the motor with out replacing the impeller in the water pump. <br /><br />I just picked up my L/U today (in 6" of snow!!!!) I was getting a steady stream of water out of the pee hole, But the impeller looked like it was seconds from falling apart. Some on this board has a saying "The water pump was working fine right up until the time it failed." They do not go slowly, they just go.<br /><br />I take it from reading over your post, that you have not had the motor running, and you were told it does not run. Have you tried to start it? If so what is it doing or not doing?<br /><br />Did you get the fax?

 

[Stefan Schmitt]

Re: 35HP Mercury - Swivel Bracket Advice Needed

Jollymon, I did get the fax. Many thanks!<br />Now... today I blew out all the rust that had fallen into the cavity where the shift shaft is. The shaft itself is nice and shiny, so the rust must've fallen down from around the swivel bracket into there. I then tightened the side nuts (the only ones still there. <br /><br />I'm missing the nuts to the bolts (those are still there) under the trim tab. What size are those? That way I can get them w/o guessing at Lowe's or HD - stainless steel.<br /><br />I also took the spark plugs out and they were...'grimy' - I have some pics and will post them tomorrow. The engine and prop turn fine. I also tested the fuse and it is fine.<br /><br />Next thing on my list is to drain the oil out of the l/u and check it and put new oil in. I'll probably do that tomorrow. Then I'll get the nuts, put those on and then try to start the engine. Btw, I assume it's 12V right?<br /><br />Here a pic of the rust I blew out of the l/u (the cavity where the shift shaft sits. I blew into the gap as well as the drain holes on the sides:<br />

<br /><br />And one with the open cowling:<br />

 

[jollymon]

Re: 35HP Mercury - Swivel Bracket Advice Needed

Dr Bones,<br /><br />How are you making out with the motor?

 

[Stefan Schmitt]

Re: 35HP Mercury - Swivel Bracket Advice Needed

Jollymon...just sent you an email, btw!<br /><br />Thanks to your manual pages, I figured out that the second - and bigger bolt - under the trim tab doesn't require a nut - That bolt is for the trim tab I figure. It's the second one in there, the smaller one that requires the nut.<br /><br />I ended up doing two trips to Lowes. I had measured the bolts using a caliper and figured I needed like 7/16 nuts. Got those but they just went on two turns and stopped. On my second trip I got metric ones and they did go on.<br /><br />Now, the second bolt underneath (not the one under where the trim tab goes) takes a nut also. The problem is that the recess is so tight, it's impossible to get a tight fit with a ratchet socket...I used a wrench until it slipped off the edge of the nut that still peeked out of the recess. Is that right? - Or are those specialty nuts that are narrower than normal ones...if I were to order it from mercury marine? <br /><br />Yesterday, I hooked up a car battery charger (obviously not enough amperage..but nevertheless) to the outboard. I turned the key...and to my amazement it actually made a couple of whirring sounds. After taking the cowling off, I saw that the starter was about to engage, but I guess, due to lack of amperage, it wouldn't quite get there. Also the trim/tilt does make noises that way. I'll hook a real battery up to it in the next few days and try again. Good thing though is that it apparently is getting juice to some of the important parts. So, it's not a total electrical meltdown either that has kept this motor from running.<br /><br />Right now its colder than a witches youknowwhat..and I'm not inclined to do much working outside. I know, I know it's way colder up north..but you know what: I moved away from Germany to the tropics for a reason...and am not much inclined to return to those straights anytime soon!

 

[jollymon]

Re: 35HP Mercury - Swivel Bracket Advice Needed

Dr Bones,<br /><br />I got the e-mail today. I did not get back to you on the nut size, because I could not figure out what size it was. Now I know why! The threads may be metric, but I swear the standard wrenches fit. I will have to try metric tonight to see if I have using the wrong wrenches. As far as the recessed nut, My 3/8" socket set fits the nut and recess but by 1/2" set does not. If I remember right the nut for that is the same nut that is on the side bolts. <br /><br />Battery? My boat came with a Lawn & Garden tractor battery $35 from Home Depot. I replaced it with the same, but I have not used the boat much. Works fine to start it, runs the tilt/trim fine. I have run it down pretty well tilting up and down in the basement. I keep it charged but when I put the boat back in the water, I will replace it with a marine battery.<br /><br />I looked back over your post, you were told that the motor did not run one week after running in salt water without being flushed. I have to say that if running in salt water with out being flush did anything to the motor half of the salt water motors in the world would not work!!!!<br /><br />Put a battery on it and give it a shot!<br /><br />Cold there, send some of that cold to me, 10-15 degrees here. I took the boat to have the transom fixed, the guy thought I was nuts, When I got it to the shop it had 4" of snow in it. It is a 13' rigid hull inflatable. Its a screamer, but the transom is cracked and rotten. I would fix, but I am not sure how to tie it back to the air tubes.

 

[Stefan Schmitt]

Re: 35HP Mercury - Swivel Bracket Advice Needed

I went to the www.mercurymarine.com site and typed in my serial #. Lo and behold: exploded diagrams and exact part descriptions. It's interesting the nuts are like $3,80/ea. and described in english measurements. <br /><br />Thing is, I believe they are actually metric, only described in english measurements. The english measurement nuts didn't have the right thread, as I tried that. I figure, this way they can charge more for the same thing...and call it a 'specialty nut'

 

[Stefan Schmitt]

Re: 35HP Mercury - Swivel Bracket Advice Needed

OK - Here are the results of my next series of 'tests':<br /><br />I went ahead and connected a Booster Pack (the ones you use instead of jumper cables on a dead car)and hooked it up to the battery cables of the outboard. The booster pack was pretty much fully charged and is one of the bigger booster packs (i.e. not a cheapy Home Depot one).<br /><br />The starter engages alright, but it turns the motor pretty laboriously. It turns the engine, but I doubt it would be enough to get it started even if it were in top condition. I didn't hook up the gasoline line at this point, since I still need to get one.<br /><br />The starter after these tests (I did the above several times) was pretty hot to the touch. Not hot enough to burn your fingertip, but hot enough to get the oil on it to smell.<br /><br />Now, the next test will be with jumper cables from my car..or I'll just break down and get a battery <br /><br />Nevertheless: What are y'alls thoughts to this? Could the starter just be bad? - Or didn't I have enough juice from the Booster Pack?<br /><br />Another thing I noticed, was that when the engine turns there's a squeeky noise (like from a rubber gasket or something) coming from the lower unit or the shaft. Is this normal?<br /><br />Thanks!