1975 500E - Water in bottom two cylinders

Ok here we go. Put in new plugs, pumped up the bulb and lo and behold she fires right up. Let it idle for a bit, and then raised fast idle lever up to increase RPMS just a bit to try to burn out some of the effects of not having run in a couple of years. Lots a blue smoke for a bit but after 5 minutes or so it cleared up. Let the idle lever back down to normal, and it idled pretty rough. Ordered my merc factory manual, cuz I know a carb rebuild is in order. After I shut it down, I pulled plugs to see how they looked. Top two looked fine, but 3 had what looked like a trace of water, and 4 was a little more pronounced. I have 118 psi in each cylinder, so was wondering where water might be getting in? Exhaust gasket maybe? Anything I can check while Im waiting on my manual to arrive? Any help is so much appreciated. Thanx all.

Re: 1975 500E - Water in bottom two cylinders

The most commom place is indeed the exhaust cover gasket. Once you get the manual change the gasket and see if the problem persists. If the bolts for the cover won't move don't force them, use heat. Even using oxy-acetlene I still broke 3 last time.<br />Eric

Re: 1975 500E - Water in bottom two cylinders

Original owner said he replaced exhaust gaskets, but admits he did it by the seat of his pants. I'm hopint he left out sealant or didnt get gaskets seated right, but if he did do it right, other than a cracked block, is there any other causes for water in cylinder other than cracked block?

Re: 1975 500E - Water in bottom two cylinders

Bad lower crankshaft seals can cause water incursion into the lower cyl's and since more water is in #4 than #3 I'd bet on that. You can take the powerhead off, then pull the lower crank seal/bearing housing assy out of the block without splitting the crankcase halves.<br /><br />Certainly possible the previous owner botched the gasket replace job. Another thing to check is the condition of the inner exhaust plate, since it'll spray water directly into the cyl's if it's been corroded thru.<br /><br />Seriously doubt cracked block, pretty rare on the 44 C.I. Fours.<br /><br />HTH and G'luck.......ed

Re: 1975 500E - Water in bottom two cylinders

Sounds like a most probable cause Ed. I also doubt cracked block as previous owner was very good about basic maintenance. Guess I'll have to try to contain my " kid on christmas eve" emotions and wait on manual to arrive. Thanx for the feedback Eric and Ed.

Re: 1975 500E - Water in bottom two cylinders

WooHoo...manual finally got here. A little dismayed at the lack of detail compared to a Johny/Rude manual, but It gives me a good general idea. This is for Ed Mc or anyone else that can give me guidance. Manual does not give a specific location of any crankshaft seals. The only mention of crankshaft seals refers to "oil" seals. Is this what I am looking for, and if so, how does water get into lower cylinders from there. Thanx for any teaching you can provide.

Re: 1975 500E - Water in bottom two cylinders

Ok, upon further inspection turns out the exhaust gaskets werent replaced. Looks like he thought the water jacket was exhaust plate. Bolt heads on exhaust cover still have original unbroken factory paint and no wrench marks. Hooboy bet those bolts are gonna be purty snug after 30 years. Any advice in proceeding is most appreciated.

Re: 1975 500E - Water in bottom two cylinders

Use heat (propane or MAPP torch will keep from melting things) on the bolts to help release them. What you don't want to do is snap off stainless bolts in alum block. Then you just about have drill out and install Heli-Coils or other type of insert. <br /><br />Last ditch if any bolt won't come out, drill out the bolt head and then when the exhaust manifold outer and inner come off, you may have enough of a 'stub' to grab hold of and get out.<br /><br />Regarding the lower crank seals, removing the powerhead will reveal the lower crankshaft bearing /seal housing assy. There are 2 seals pressed into this housing. I believe on your motor the lower crankshaft main ball bearing is pressed on the shaft and slip-fits into the I.D. of the lower housing assy. <br /><br />So, you remove the (3) bolts holding the housing to the block (remember to use care when loosening these, too). Then, you can use a puller plate, slide hammer, or similar pulling device, fastened to the threaded pulling holes in the bottom of the housing. An automotive harmonic balancer puller, with the center screw pressing against the crankshaft, will also work.<br /><br />What you have to be careful about is trying to pry on any of the (3) mounting 'ears' as they are somewhat fragile and could break if you pry the wrong way.<br /><br />Once you remove the housing assy you'll see an O-ring which must be replaced also. Punch out the old crank seals with a suitable tool and press in new ones. Note the direction the seals face as this is critical. "Lips down" on both. The solid face of each seal points up.<br /><br />Anyway, that's just an overview, your manual should run you thru the entire procedure. <br /><br />HTH & G'luck........ed

Re: 1975 500E - Water in bottom two cylinders

Great info Ed. Mucho gracias. Gonna start tonight with some heat and PBblaster. Hopefully those buggers will let go without causing too much pain. I have one other question that I have been curious about. I know most of the folks on this forum are DIYer's like myself. I know I dont own a torque wrench and wonder how critical other than on headbolts, the proper torque is? Should I go ahead and get a couple of torque wrenches (one ft/lb and one inch/lb)?

Re: 1975 500E - Water in bottom two cylinders

200 In-Lbs on the exhaust manifold bolts, 150 In-Lbs on the bearing cap bolts, 70 In-Lbs on the back cover (AKA cyl block water jacket cover).<br /><br />Wouldn't worry about most other torques on the powerhead except for crankcase and rod bolts. For example, I've never torqued the nuts that fasten the powerhead to the center section, just tighten them down Good 'N Tite! You'd have to use some sort of crow's foot or whatever to even be able to use a torque wrench on those.<br /><br />I see Sears has a good Autumn Weekend Sale on torque wrenches, maybe it's time to fill up the toolbox!<br /><br />They also had a nice little digital VOM for $9.99, good enough for any electrical testing a layman would need to do on most Merc's.<br /><br />Have Fun!...............ed

Re: 1975 500E - Water in bottom two cylinders

Hehe...well my birthday is just around the corner and hey, I been a good boy!! Guess I better plan a trip to Sears this weekend. Thanx again.

Re: 1975 500E - Water in bottom two cylinders

Ok...making some progress. Called for Eric B cuz I see you have the same motor. Got a couple of the exhaust cover bolts loose (only broke one so far and it left a decent stub). Just started with heat and PBblaster to see if I was gonna be able to get it done, and now I feel confident enough to proceed. So am in process of removing powerhead. Am going out of town for a few days and want to lay it on its side and really let the solvent soak in. Got everything disconnected (I think) except for the bottom shift nut wayyyy down in the bottom cowling. Any tricks other than the 1/16" at a time turn and then my real concern, how da hell do ya get it back in on re-assembly? Thanx for everyones assistance. Y'all are the greatest!!

Re: 1975 500E - Water in bottom two cylinders

I've had the powerhead off every time I've had to open the cover. Once the powerhead's off the cover is easy. I guess the best way without pulling the powerhead would be just go slow with as small a ratchet or spanner you can find. Once it's out wire brush the threads and put loctite anit-sieze on it and you can probably mostly get that bolt in by hand or with pliers then do the last bit of tightening with a wrench.<br />Eric

Re: 1975 500E - Water in bottom two cylinders

I am pulling the powerhead. My question was how to get the "hidden" shifter linkage bolt that's way down at the bottom below the powerhead and under all of the shift linkage. I managed to get it out (took 1/2 hour, almost as long as all of the other dismantaling). I'll worry about getting in back in after I get the exhaust gasket replaced. Now Im stuck again. The powerhead will rock back and forth, so it doesnt seem to be stuck, but I cant get it loose from the leg. Tried in gear and in neutral. Nothing in the manual, it just says hook it up to a hoist and remove it. I dont have a hoist, but I cant believe it weighs so much that I would need one. Book says the entire engine is 170 lbs so surely the powerhead cant be more than 80 lbs or so. Any more advice on how to get powerhead seperated?

Re: 1975 500E - Water in bottom two cylinders

I just use a come-along from a roof beam to the flywheel with the motor on a good stand, then kick the motor until the stand and lower section fall and the powerhead stays in the air. (seriously ) <br />Take the leg off before you pull the powerhead, it makes it a lot easier. (no messing with driveshaft)<br />Eric

Re: 1975 500E - Water in bottom two cylinders

So are you saying that I gotta remove the leg too before the powerhead will come off? Manual doesnt really show that step.

Re: 1975 500E - Water in bottom two cylinders

I just did it to get the driveshaft out of the engine, it's one more thing to fight when getting the PH off. The leg's easy to take off so you might as well do it.<br />Eric

Re: 1975 500E - Water in bottom two cylinders

Never mind, I got er off!! Can't believe how dumb I can be sometimes. Trying to raise it, it was hanging up in the back. Hoisted it as far as it would go, it was bringing the innards from the drive shaft housing with it as the lower cowling was coming up with the powerhead. I looked and looked for one last bolt but none to be found. Suddenly a flash hit me. There were two grounding straps that some idiot forgot to undo!! DOH! Took them loose and voila. In my effort tho, I tore the gasket under the powerhead seat and the drive shaft housing. Is this a big deal or can i just slap a little gasket sealant on it when I reassemble.

Re: 1975 500E - Water in bottom two cylinders

lol, it happens. <br />I'd probably replace that gasket, you dont wanna have to lift it up again later if it fails. Which is it on this page? 11 or 7?<br />web page <br />Eric

Re: 1975 500E - Water in bottom two cylinders

Hey Thanx Eric...I been outta town for a few days and just got back. Its #11 for sure. Tore it right between the two bolt holes on the left hand side. Got back and was able to get all but one of the last bolts off. So I got 12 out and 2 broke. Not great but honestly I was expecting and prepared for worse. And I just realized that both of those gaskets had fresh permatex sealer on them. Those must be what the seller thought were the exhaust gaskets that he said he replaced!!! No wonder it didnt solve his problem. <br /><br />Ok, exhaust plate is off. Top of exhaust compartment is covered in carbon and soot. As you get down to #3 its about half carbon and half clear, on down to #4 it is nice shiny metal. Can see a lot of scale right at a gasket tear in the opening between 3 and 4. Now correct me if Im wrong, but I am seeing this all as an indicator of water intrusion where it should not be. Can post pics if necessary.