While I've got the heads off....

[realboats]

Hi Folks. 1986 Johnson 110HP/1.6L Sea Drive. I've made a number of posts here about the fiascos I've endured with my engine failing while offshore. Problems range from stripped starter bolts to multiple ignition problems and possible fuel problems.<br /><br />So, in a desperate attempt to gain some trust in the engine, I ordered virtually all new ignition parts, got rebuilt carbs (as it turned out the old carbs were clean), and pulled the powerhead for a closer look.<br /><br />Measured bore of all cylinders in various spots up and down the bore. Everything within .002" of spec. Stroke is dead on. Piston clearence is dead on. (That alone helped restore a little of my faith in OMC engines)<br /><br />The piston tops are lightly carboned. Will mild brushing with a wire brush (SS, bronze, copper?) and some solvent be worth the effort or should I just run some OMC tune-up after she's back in the water?<br /><br />I don't want to tear down the engine any further. Is there a way to check for possible crank/bearing problems while I have the heads off? I can't feel any slop in the crankshaft from the flywheel end, and there is what seems like normal backlash (correct term?) at top and bottom of the strokes. <br /><br />Also running a tap and die through the threads which were gummed up from the thread sealent. They cleaned up nicely. The sealent used for the head bolts was white. I plan on using aviation form-a-gasket for the head bolts. Will that be ok or should I consider some other type of thread sealer/locker/corrosion protection? The OMC dealers here don't carry ANY of the thread sealers.<br /><br />After the heads are back on and everything is back together, I'll be running the engine by starter to check compression, spark and testing all the ignition components. This makes me a little nervous because no lubrication will be getting to the engine due to lack of fuel flow and combustion. I thought wiping the cylinder walls with some synthetic lube may help the lack of lubrication but this won't help the rest of the engine, like the crankshaft and needle bearings. How do you keep the engine lubed during cranking tests?<br /><br />Well, that ought to hold you for a while. LOL Enough questions already! Thanks!

 

[Solittle]

Re: While I've got the heads off....

I have a pair of 1987s. <br /><br />Make sure you do a sync & link + timing when you get it back together. You do not need to run the engine to do these. When these are done start it with your regular fuel mix. <br /><br />Since you did not open the engine up the internals should still have plenty of lube.<br /><br />YOu do not mention if you have the OMC shop manual. If not get one PERIOD.<br /><br />One more thing - If there is anything in your prior posts that relate to what you are doing now you should continue posting there rather than starting a new one here. In reading this I had no clue on what you or others have posted.

 

[Dhadley]

Re: While I've got the heads off....

While the heads are off replace the deflectors. Those 4 small pieces of hose in the water passages.<br /><br />Just curious -- how did you measure the piston clearance if you dont have the pistons out?

 

[realboats]

Re: While I've got the heads off....

Thanks for the advice, SoLittle. This is a new chapter in the saga of my engine. I've had numerous problems with this engine, and I figure each one warrants a new topic. Researching Johnson outboards would have saved me a lot of heartache before buying one. This one seemed to run fine on the stand before I bought it.<br /><br />Yes, I agree, a factory shop manual is a must! Actually, I have 3. The first two were the wrong ones. It wasn't until a lot of research and bugging people that I was finally able to nail down what this engine is. I also have the Seloc manual. It can be a good supplement, but it will lead you astray if you're not careful. My manual is actually for the 1986 110HP, but I have the parts catalogs for both the 110 and the Sea Drive. <br /><br />I was advised last fall to do a sync and link and I wouldn't be surprised if it was you then, too. If I remember correctly, you have the two sea drives with the beautiful paint jobs?<br /><br /> You probably know that the Sea Drive engine has a throttle/shift linkage that is quite different from the standard 110 HP. I've been able to fumble my way through the sync and link using the standard 110hp manual. Is there anything significantly different between the 110hp and the Sea Drive as far as the Synch and Link go?<br /><br />Thanks!

 

[realboats]

Re: While I've got the heads off....

Thanks for the heads-up on the cooling deflectors, Dhadley. I just pulled them out of one bank. One thing that bothered me is that the bottom deflector was squashed to the point of the hole being almost flattened closed. It's like that on both sides. Perhaps wrong deflector?<br /><br />I'll be buying new ones. Are they glued in place? My manual doesn't say. If so, will high temp silicone do the job?<br /><br />I had planned on cleaning the cooling jackets with a bronze gun bore cleaning brush. There's some residue, probably salt, that should clean up pretty easily. <br /><br />As for the "clearance", I screwed up. Sorry about that. Everyone probably thought I mean the piston groove clearance? What I meant was the space between the piston side and the cylinder wall. It was the only way I could check the piston diameter. Probably not necessary, but I tend to worry about these things. I used thin pieces of paper measured with a mic for feeler gauges.<br /><br />How about the carbon on the piston heads? Should I clean them or just let the decarb process do it after the engine is running?<br /><br />Thanks again for your help. You folks are GOOOOOD PEOPLE!

 

[Solittle]

Re: While I've got the heads off....

realboats - Yes I am the guy with the Merc black SeaDrives. I have the OMC shop manual and followed it for the sync & link. You can use a procedure that is here somewhere (use the Search) for adjusting the timing without running the motor by Joe Reeves I think.<br /><br />I replaced the deflectors on mine & used the OMC deflectors. I lubed the new ones with a bit of dish soap to get them to slide in.<br /><br />While you have the heads off you might try to take the caps off the heads & clean the crud out. Mine were packed. You need to be careful as those bolts snap rather easily.

 

[Dhadley]

Re: While I've got the heads off....

That was probably the right deflector -- at one time. All it is is a single piece of the old double line fuel hose. With time they get all flat and completely out of shape as you can see. The new ones (part # 322411) will be fine.<br /><br />Measuring the top of the piston wont really tell anything. Thats the smallest part of the piston and there is no published spec as far as we know of. Its nothing to worry about.<br /><br />Actually a thin layer of carbon on the piston dome is a good thing. You obviously dont want big chunks of carbon but a normal layer is nothing to worry about either.

 

[realboats]

Re: While I've got the heads off....

Many thanks to both of you gents, Solitle and Dhadley. What you said about the piston top diameters makes perfect sense from what I experienced.<br /><br />I did take the head covers off and they had a lot of salt on the inside of them. Do you recommend removing any other covers to clear out the residue in the water jackets? I've collected quite an assortment of brushes to scrub those areas clean of salt. BTW, removed the water cooled rectifier and holy cow what a huge cavern under that thing! <br /><br />Something else I was wondering about, and it may sound absurd but I expore every possibility, but is there any way to treat the water jackets to help prevent corrosion before putting the covers back on? Perhaps some type of corrosion inhibitor or remover. I suspect not, at least with aluminum. What treatment you could give those cooling passages will probably get washed out the first time the engine is run. Nevertheless, perhaps there is something available to treat the cooling passages and perhaps slow down the corrosion rate? Big bucks for anyone who could invent something like that. <br /><br />Thanks!

 

[Solittle]

Re: While I've got the heads off....

If you find an effective treatment be sure to post it. The most effective way that I know of to keep the crud to a minimum is to fresh water flush it. There is a product called Salt-a-Way that I have heard of but have no experience with that you could investigate.

 

[realboats]

Re: While I've got the heads off....

I figure if I use a corrosion inhibitor like CRC or Corrosion Block, it will just get washed away. If a sealer like POR-15, if it could take the heat, would probably flake off and screw up the cooling system. If there was a really tenacious grease available, it may give some limited protection. Guess I had better not upset the outboard gods and leave it the way it is. <br /><br />I put the muffs on my outboards and rinse them religiously, but with this boat on a mooring that won't work out too well. <br /><br />Another question if I can...The gasket head covers are simply a gasket the shape of the head covers with the temp sensor hole and bolt holes cut into them. What bothers me is the gasket head covers have channels cut into them apparantly for cooling water? Well, the gaskets will cover these channels up and make them useless. Also, the engine side of the gasket is exposed to the cooling passages of the engine head. <br /><br />The factory manual says very little about them. Just to coat the gaskets with OMC gasket sealer, install the gasket and head cover and torque the bolts starting with the inside ones and working out. These things are weird, to say the least!<br /><br />So are the head cover gaskets completely coated with gasket sealer and installed without any modification to the gaskets? It makes no sense to me to cover those cooling channels on the head cover. Also, when I removed the head covers, those voids or channels were pack full with what looked like salt. I can't figure out how it got there.<br /><br />Would really appreciate some advice on this. It's quite a riddle to me. I've been searching this forum but haven't found anything specific to this.