mercury 1150 water in cylinder [UPDATED, removed powerhead with PICS]

fishdog4449 · #1 June 7th, 2008, 01:52 PM

hey guys!
Number 3 plug on the Mercury 1150 (1974) has little water droplets on it so I'm assuming water intrusion. Compression is
1-122
2-135
3-130
4-135
5-135
6-135

I haven't ran the motor in the water yet, just on the stand and it has not be decarbed (doing it today)
My question is is this a serious problem that could affect the motor or is it just because the motor's been sitting so long?

Thanks

Chris1956 · #2 June 8th, 2008, 07:59 AM

It is probably a big problem. Run the notor on the muffs for 1/2 hour and see if the problem persists. If so, you have either a leaky exhaust baffle or inner exhaust cover. The problem is that th bolts break when you try to remove the exhaust covers, so the repair is a drag...

fishdog4449 · #3 June 8th, 2008, 08:23 PM

well, I ran the motor for a while on the muffs, and no water drops but the plug is just a tad cleaner than the rest, not by much though.
The motor is in mint condition as far as rust and corrosion goes, will i still be battling broken bolts?
I was planning to take the boat out for a day trip to the lake next weekend, but it doesn't sound as if that would be a good idea?

gregpro50 · #4 June 8th, 2008, 08:53 PM

I would fix the problem before you take it out. If the motor is freshwater then you shouldnt have too many broken bolts. I just took apart a saltwater 115 and I only had 1 bolt break. It helps if you soak the bolts in a penetrant oil and use an impact to remove them.

fishdog4449 · #5 June 8th, 2008, 09:43 PM

If I am looking at the right exploded diagram, it looks to relatively easy to pull the cover assembly and determine the problem(bad gasket, seal, etc). Am i right in assuming this?
Thanks for all the help guys!

(EDIT) Just went out and looked at the motor and lower bolt on the right side is way to far down to reach. Does the lower cowl section come off easily, or do you have to pull the powerhead?

Chris1956 · #6 June 9th, 2008, 10:15 AM

Fish, You can remove the exhaust cover w/o pulling the powerhead, but it is a difficult, cramped way to do it. In addition you will not be able to coax out a lot of the bolts. I really recommend you pull the powerhead and lay it on a bench.

Use a propane torch (or hotter) on each bolt, spray with good penetrating oil and use a hand impact driver to loosen each bolt gently. Coax them out.

BTW - I had my drill press right their to drill and retap the bolts I broke. It was only 6, but I later got three of the broken bolts out.

fishdog4449 · #7 June 9th, 2008, 10:56 AM

Well I want to prevent broken bolts if at all possible, so I probably pull the powerhead. I'm gonna get the manual before I do so, but just wondering how much work is it to physically get the powerhead off the engine?

gregpro50 · #8 June 9th, 2008, 11:18 AM

I just changed my powerhead and it wasnt that bad. 8 bolts hold it to the mid section and you just have to pull off all the wiring. I had use of an engine hoist though.

fishdog4449 · #9 June 9th, 2008, 11:31 AM

doesn't seem that bad. I have an engine hoist so that wouldn't be a problem. well thanks for all the help guys!!!
ill let yall know what i find once i get her apart

fishdog4449 · #10 June 9th, 2008, 02:53 PM

Ok guys, curiosity got the better of me. So I went out and tested the bolts to see if they would come off. The five i tried came off quite easily in succession with just a normal socket. Now, supposing all the rest are this easy, is there any way I can get to that lower right bolt to get it off? If it all possible, I want to avoid pulling the powerhead but I will if it turns out a few bolts get stuck. I know you guys have much more experience than me so I trust your judgment either way.

gregpro50 · #11 June 9th, 2008, 04:18 PM

If you take all the bolts out for the support for the lower cowl you can wiggle it around enough to get in there if you take the front and the back pieces right off. In my experience it seems the bottom bolts are always the ones that can be difficult to get out on the exhaust cover.

I'm not an expert mercury mechanic by any means but just a do-it-yourself boater that has learned alot of this the hard way...

fishdog4449 · #12 June 9th, 2008, 06:14 PM

Well almost all of the bolts came off very easily. I have removed the lower cowl and cowl pieces that cover the engine, but can't get to the three lowest bolts. The only way i can see to take the cowl off is to pull the powerhead. See I shoulda listened to you guys in the first place! Anyway, the bolts came off easy but several were almost downright loose. I didn't have to use any force on any of them. Would that be part of the problem that they weren't torqued in enough? I know that the proper way to lift the powerhead is to use a lifting eye on the flywheel, but where would such an eye screw in?

fishdog4449 · #13 June 16th, 2008, 10:20 PM

ok guys got the powerhead off and cover removed. now my question is what should i be looking for...everything looks normal to me. but...cylinder number one has a few scores, but at 122PSI, im not worried about it!!!
When I pulled the plugs to set motor down, number 3 had rust spots on it so there definitly is water getting in there somehow.
Here are some pics maybe you guys could spot the source of water.

On a side note...I really hope this isn't the case becuase i just wasted a bunch of time but....all cover bolts were torqued to maybe 5-10ft/lbs at the most and no permatex on the cover. could this have been the problem all along?

Faztbullet · #14 June 17th, 2008, 01:49 AM

Check out the enclosed....

fishdog4449 · #15 June 17th, 2008, 12:27 PM

Thanks fatz here ya go?
How can you tell it has been hot or overheated?
I degreased the cover and cleaned some of the carbonation off, which revealed two cracks in the cover. One is by #6 and the other one is between #3 and #2.
Pics of the cracks are at the bottom..I'm thinking a little JB Weld would be ok for those.

Fatzbullet, here are the pics you requested.

Cracks...

fishdog4449 · #16 June 17th, 2008, 07:11 PM

I want to remove the inner water jacket cover to see if there is any problems with that gasket and cleanup the cover, is this a bad idea?

gregpro50 · #17 June 17th, 2008, 07:43 PM

Definitely remove the inner jacket cover while you are in there and replace the gasket. However, that is where the bolts break on me...

The first crack picture looks like a defect in the casting. The second is definitely a crack. Either take it to your local welder or find a replacement (which is what I recommend). JB usually wont hold up to the expansion and contraction of the aluminum.

Faztbullet · #18 June 17th, 2008, 10:37 PM

Good pic's, I was wanting to see if divider was steam cleaned. It was not. Usually if one gets overheated good, gaskets take on that shiney look from plate losing it tightness, which you said bolts was loose. The inner exhaust plate & gasket can be changed but use heat on the bolts. They are epoxied in from the factory with Resiweld epoxy. Put all gaskets & plates back together dry, no sealers. Also replace that cracked plate, dont try to pacth or weld as weld will make it draw and may warp plate.

fishdog4449 · #19 June 17th, 2008, 10:59 PM

Well neither of the cracks go all the way through but I will look for a replacement. The second crack from the other side appears that someone hit that area with a hammer, the other side is dented in.

I did remove the inner cover and the gasket was pretty bad so I will replace that as well as the other two gaskets.

fishdog4449 · #20 June 20th, 2008, 10:36 PM

ok guys one final question
what should the inner and outer exhaust bolts and powerhead bolts be torqued to when reinstalling?
thanks so much!!

emckelvy · #21 June 20th, 2008, 11:50 PM

Torque on all bolts should be 150 inch-lbs.

fishdog4449 · #22 June 22nd, 2008, 03:33 PM

Ok put everything back together early yesterday. Ran it today, nothing changed. Plug number 3 still has a load of white/grayish scum on it after running.
Anywhere else water could be getting in?
I know this motor doesn't have a head, but could the cover by the plugs have a leak in the gasket?

gregpro50 · #23 June 22nd, 2008, 09:49 PM

No the gasket around the spark plugs cant cause a leak into the cyl. I wonder if there is a crack in the water jackets somewhere from overheating or something.

fishdog4449 · #24 June 23rd, 2008, 12:36 PM

Well, when I had it apart it looked pretty clean inside, not to mention outside it looks mint, but there could be a crack inside somewhere. I'm wondering if it just needs to be run hard for a while. I've only ran it on the stand (muffs) for periods of 5 -10 minutes, and it ran/idled fine. Takes a little effort to start, but thats common for these motors so ive heard. Figured out that I can pump bulb hard, give her some neutral throttle, hold choke and crank. After about 5-10 seconds of cranking, she sputters a bit, one more crank and she fires up quite nicely.

My dad said that I should just run it and not worry about it but I'm worried about it quitting on me in the middle of the river.