evinrude rebuild questions.

i am currently rebuilding my '79 rude 85hp 85999. this is the first rebuild i have ever done. i have just got the new piston kits, bearings, and gaskets in the mail, and the block and pistons are going to the machine shop tomorrow for boring. my questions are what kind of greases/ oils/ sealants should i use when i reassemble this engine? and what other changes or checks should i perform while i got the powerhead off? (carbs rebuilt last year and boat ran maybe 15 hrs in that year). might i mention i recently bought this motor and the guy i got it from took it to the boat shop for general maintenance every spring and late fall.

Re: evinrude rebuild questions.

Why the rebuild hisey? Curious....that's all <br /><br />Do you have an OEM manual to go by? Generics are OK but OEMs are much more specific about a particular model.<br /><br />Have a squirt can with a good TCW-3 in it. You'll use a lot during assembly. <br /><br />Vaseline is good for holding needle bearings in place.<br /><br />A good gasket sealing compound is a must. Get a can at the local auto parts store....preferably one with a brush attached to the lid.<br /><br />I like to chase out the bolts holes with a tap. Makes assembly easier. And clean, clean, clean.<br /><br />And I would rebuild the carbs even though the previous owner says the were last year. Replace any fuel line that have become hard from fuel.<br /><br />Take pictures if as you disassemble use them as reference. Muffin pans make good holders for nuts and bolts. Mark the cup for where the bolts came from. Saves guess work.<br /><br />I'm sure some of the other guys will chime in and give you some ideas.<br /><br />Keep us posted as to your progress.

Re: evinrude rebuild questions.

the rebuild is due to a blown ring on one piston. after getting the motor apart, i found that the end cap on that rod wasn't torqued properly and had come loose, causing the piston to have lots of play and eventually, breaking the ring and scoring the cylinder wall. yes i have an evinrude model specific service manual and it is a lifesaver. wouldn't have gotten this far without it. thanks for the advise obj, i figured i should do everything i could while engine is tore down that the budget allows.

Re: evinrude rebuild questions.

well spending 800 dollars only to pop another piston is a waste of time.<br /> dont allow the budget to dictate all of it.<br /> a new bottom main is a must as are new rodbolts.<br />rodbearings I may reuse if the old ones are in good shape and kept with the same rods, wristpin bearings I replace, rebuild the carbs and replace the fuel pump. check the recirc check valves or replace them. replace the tstats and water pump.<br /> use BRP gaskets as they work about the best. use OMC adhesive M or its BRP equivalent where specified and Gel seal where specified as well as a can of BRP gasket maker where specified.<br /> throw the silicone in the trash, it has no use on that motor.<br /> check the water deflectors and the cyl head surface flatness as per the service manual.<br />if you dont have the seal drivers fror the endcaps take them to a BRP dealer and let them install the seals.<br /> I think your piston stuck due to heat and created the rodbolt issue as the rod wont affect a piston.<br />it may come out the block but wont affect the piston to cyl wall clearence.<br /> the biggest issue is clean clean clean then clean it again before assy and keep it clean while assembling.<br /> that means all intake transfer port and exhaust covers to be removed.<br />dawn dishwashing liquid and hot water with a good babybottle brush is good <br />do it right do it once and it will go 20 years in freshwater.<br /> I use pipe sealant with teflon on the bolts unless otherwise specified.<br />head bolts I wipe with gasket maker.<br />forget the locquic primer on the crankcase mating surface, unless your quick it kicks off the gel seal to fast and causes a shimming effect<br />clean the mating surfaces with acetone or any solvent that does not leave a film.<br /> I cant stress cleanliness enough.<br /> I use the 3M pads on a drill to clean the gasket surfaces.<br /> I install the pistons in the block taking care to mark which rodcap goes to which hole then install the heads. then flip the bloc and push all the pistons down.<br /><br /> assemble the crank and install it making sure the beaing locating holes line up on the pins, then install the end caps and loosly bolt them in place to hold the crank.<br /> then pull the rod to the throw making sure not to scratch the journal and assemble the rods. use 1/4 drive on the cap bolts until your positive cap alighnment is correct, if you tighten the cap out of align the rod is junk.

Re: evinrude rebuild questions.

well---for one, i have spent no where near $800 to "pop" another piston in. for two---i see it as no waste of time because i have gained tons of experience and have learned a lot about the way my motor works and how to work on it. but on the other hand, thank you for the advise, i'll take any and all i can get with this deal. the block is at the machine shop and should be ready to go back together early next week. i'm sure i'll be back for help when i get the block back. thanks again guys.

Re: evinrude rebuild questions.

I agree with RB (again) that a lose rod cap wouldnt do that to a ring. But it sure would tear up a crank! If yours is still OK you're doing real well. <br /><br />Tell us more about the set up. If the broken ring is on the starboard side and the motor was set up in the low 5000 range we may have the answer as to "why". Especially if we were using something other than Champion plugs. And something other than 87 octane.<br /><br />This is assuming that the ring broke. Now if the corner is burned off the piston on the exhaust side, thats a different story.

Re: evinrude rebuild questions.

(Gasket Sealers)<br />(Usually available at any reliable automotive parts type store)<br />(J. Reeves)<br /><br />Do Not use any type of sealer on outboard carburetor or intake manifold gaskets as this would cause blockage of various fuel/air passageways. Also, there are new type gaskets, including head gaskets, which are used through out the engines that are coated with a substance that gives a shinny appearance to them. These gaskets are coated with a self sealer and are to be installed as is.... no sealers! Older style head and fuel related gaskets that are not coated with this substance are to be simply coated with oil.... nothing else.<br /> <br />All other gaskets (hopefully I've not overlooked anything above) should be coated with Gasket Sealer (the type that comes in a can that has a small brush in its screw off cap). This also pertains to some water pump installations that use a gasket between the plate and the lower unit housing.<br /> <br />Marprox Sealer 1000 or OMC Adhesive or Boat Armor Sealer 1000 (same substance) should be used on any metal to metal or metal to plastic surface (such as impeller hsg to plate) to eliminate air leaks. It should also be used on the Spaghetti tubing that is used on many powerhead crankcase halves, lower unit skegs, etc. I have found that this substance works quite well on various "O" Rings such as what are found on lower unit carrier and upper driveshaft bearing housings (Note that this substance is obviously not to be used on all "O" Rings).<br /> <br />DO NOT use any sealer on the large "O" Rings that are used on the upper and lower crankcase heads (The housing/heads that slide over the top and bottom of the crankshaft). On those "O" Rings, use only a coating of grease.<br /> <br />The exception of surface to surface contacts pertains to the later model matching crankcase (block) halves (which does not incorporate spaghetti tubing) which call for "Gel-Seal", or any other surface that calls for Gel-Seal. This substance seals in the absense of air, and if called for, must be used. One other form of Gel Seal that can be substituted is "Loctite #518". Nothing else that I know of will do!<br /><br />I advise against using silicone or permatex on a outboard engine. It simply will not function properly. The exception to this (as per OMC's recommendation), is to use the black Permatex (heavily) on the gasket 306242 which seperates the inner exhaust tube from the exhaust housing on the 1959 35hp and 1960 to 1970 40hp OMC outboards.

Re: evinrude rebuild questions.

just by looking at the crank, it appears that there is no damage at all on it. it is just as smoothe and nice looking as where the other rods were hooked up. the rod looks like it took most of the beating. the ring clearly broke (small chunks floated around in the combustion chamber) and damaged the wall. when i split the crankcase, i saw VERY little evidence of any type of sealer, almost looked like two very small dabs of superglue or something. the plugs are champions and 87 octane was always ran.

Re: evinrude rebuild questions.

I guess its possible to tear up a rod and not damage the crank but have the machine shop inspect that as well. the journal tolerance is about 1/2 of 1 thousanths of an inch. .0005" from nominal. something like that. the rod is the same. any surface pits or "washboards" will destroy the new rod and bearing very rapidly. my bet is the piston started breaking apart and sticking before the rodcap came loose. a loose cap usually comes out the side of the block for inspection. thats why you NEVER reuse the rodbolts, they tend to break, not each time but quite often.<br /> the bottom main absorbs the up and down(axial) motion of the crank and is the thrust bearing, change it any time its apart.<br /> if you can get by changing a piston and a rod and doing the rest of the nessasary stuff for much less its good.<br /> I have a 98 115 on the stand now that I finally got the rings for tonight that has cost me about 1400 in parts crank set me back 450, pistons at 54 a piece bearing kit was about 300 then we started with the "Misc" stuff .

Re: evinrude rebuild questions.

whatever you do dont locktite the rod cap bolts on they wont be tight enough and fly off.