Disassembly & Cleaning

Let me briefly state that I appreciate everything you gentlemen are doing to help us novices (me). I have never taken apart any engine before. My experience is limited to changing out car waterpumps, alternators, and other basic components. I would never have attempted what I am doing without the support of this forum, and I am grateful for that. I agree that I should have solved the original problem with this engine early on ("Lazy Cylinder..." post), however intimidating as it was to me at the time. Yes this was a "run it till it breaks" engine. Not any more. I've learned my lesson. Thank you Rodbolt for recently pointing out that my head gasket was possibly leaking. I've got to figure out how that happened. I'm getting hundreds of hits on my webpage regarding this issue. I have promoted iboats.com on there in several places. Now, I'm done with the run on paragraph...so here we go with meat & potatoes.<br /><br />1) Trying to clean exhaust manifold, book says "wash with solvent" & "scrape" for this and other parts of the internal objects. Solvent? I'm not a smoker or a pyro so is gasoline a sufficient solvent...otherwise another run to the store for carb cleaner.<br />Exhaust Manifold <br /><br />2) Some areas on the exh cover plate (water side) as well as exh cover have thick areas of "build up" (corrosion). Can I use a wire brush to remove this. If so what happens when the paint gets removed...is there some sort of paint I can later apply to protect the metal?<br />Exhaust Cover <br />Exhaust Plate <br /><br />3) Observation: Exhaust cover thermostat spring loaded plastic insert wouldn't move in its hole. There was some corrosion on the metal part prohibiting the plastic piece from moving. Further, I cannot figure out how this works (to limit or allow water...?).. so not sure if this is a problem or not (contributing to failure).<br /><br />4) A number is hand-etched into the lower area of my crankshaft. Is this normal - could this have meant that the crank was replaced before, or worked on, or what...<br /><br />5) Crankshaft has sort of "rings" that the book doesn't show in the diagram for my engine (but does show this for the 200 and they are called "sealing rings")....?<br /><br />Sorry this is a book...

Re: Disassembly & Cleaning

can we get get an idea of what your working on?<br /> try not to wire brush aluminium if its gonna be exposed to salt. the steel tends to bond with the casting and salt will accelerate corrosion.<br /> I use the 3M pads on a drill.<br /> post a model num,ber so we have an idea of whats happening to what. also post why its being dissasembled.

Re: Disassembly & Cleaning

S150TXRV<br />failed #5 rod bearing<br />Detailed Log With Pictures

Re: Disassembly & Cleaning

(1)Will take some strong solvent and a putty knive to clean exhaust divider, then I finish up with the 3m pads. If they ran cheap oil you will now understand why you don't.<br /> (2) Rustoleum to replace paint coating. Be sute to prepare before painting.<br /> (3) It is designed to move out when the pressure is too high and relieve. Very important, incorrect operation will cause motor to overheat.<br /> (4) It means it has been either replaced or repaired.<br /> (5) Those are sealing rings and if they don't seal properly, the engine will run poorly.<br /> Don't know what book you are looking at. Factory manual explains how to check them for wear.

Re: Disassembly & Cleaning

get some clean pics of #5 rod journal and crank journal.<br /> that will determine if its a rebuild candidate or a replacement factor. I may know where a late model crank is that can be had reasonably.

Re: Disassembly & Cleaning

Click here for update with full size pics <br /><br />Highlights:<br />-Confirmed that pressure valve was stuck shut.<br /><br />-Sealing rings are intact and appear OK.<br /><br />-Crank 5 journal as well as rod 5 journal are dark (not shiny) and somewhat, although seemingly minimally, rough in some places.<br /><br />Got pics of this, but have not solvent washed parts yet.

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your crank and #5 rod are trash, sea anchors we calls em.<br /> you will need a good used crank,or a reman and at least 1 rod. dissasemble any main bearings paying very close attention to the top bearing as its lubricated from the bottom bearing. your problem was water intrusion, I doubt the stuck poppet was the cause as it only maintains water pressure.<br /> you may yet need to call Bill about a crank.<br /> any pitting or roughing of any needle bearing surface is usually grounds for junking. the tolerance is less than .0006" so any polising with more than crocus cloth will normally polish it out of spec.<br />the block will most likly need a sleeve. best to find a competent machine shop with 2 stroke experience.

Re: Disassembly & Cleaning

I solvent washed crank journal 5 and took a picture: Crank Journal 5 After Solvent Wash <br /><br />It's cleaner now...does that alter your assessment of the crank? <br /><br />Who is Bill?

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It is now cleaned up trash. Not sure who Bill is but you need to if he has those parts. 90-99 cranks are rare. Sticker shock on the price of those two parts from Yamaha will getting you to want to know him.

Re: Disassembly & Cleaning

P341 of the Clymer book says I can pressure clean the block with water:<br />"Use hot soapy water to clean the cylinder block, exhaust covers, and cylinder heads. Clean the block with pressurized water..."<br />Unless y'all see a problem with that, I'm on it. Got a 5 HP pressure cleaner from a friend ready to go.<br /><br />The crank has been fully solvent washed now:<br />Picture Of Clean Crank <br /><br />"Bill" come out whereever you are. Drop an email to jasonalden@yahoo.com

Re: Disassembly & Cleaning

After you get it clean, dry it with air and immediately oil the cylinders. This is normally the last step before you put it together.<br /> If you don't oil it the cylinders will rust and it needs to be clean when it goes together.

Re: Disassembly & Cleaning

you now have a very clean shiney junk crankshaft, about the only thing its useful is to cut off the splines and weld a socket to them for use as a driveshaft holding tool.<br /> Bill Klyver runs B&T outboard service in Moyock NC. he may have a good crank and some connecting rods as well as some used main bearings,<br /> always replace the bottom main anytime the crank is out, he may toss in the seal rings.<br />any pitting especially pits that a needle bearing may get stuck on means a junk crank,rod and wristpin surfaces.<br />remove all the pin bearings and carefully inspect the bearing surfaces as well. the tolerance on the bearing surfaces is .0006" or less and the average human hair is .003" in diameter. you do the math.<br /> if a bearing sticks and slides instead of rolls it becomes a slider bearing. slider bearing life span is 5 min or less.

Re: Disassembly & Cleaning

Is there a serial number stamped somewhere in the block of the powerhead? I have a suspicion that this powerhead has eiter been:<br />a) Rebuilt before, or<br />b) Completely swapped out.<br /><br />Need to trace it back and see what Yamaha says based on a serial.<br /><br />Previous owner is not returning my calls. <br /><br />Block is going to a local machine shop today for a look and maybe more.

Re: Disassembly & Cleaning

Today I delivered the block to a marine machinist. Several notes of interest:<br /><br />1) A hole was discovered on the block on the raised area between the V. Hole is approximately across from cylinder 3, and above cylinder 5 (rod bearing 5 blew). The hole is a little smaller than 1/8 inch diameter. (Now it is all adding up, what happened). He advised he will be able to weld the hole.<br /><br />2) Machinst determined my cylinders and pistons are stock size; that is, the cylinders have not been bored before.<br /><br />3) Machinist recommends to bore cylinder 5, and hone the others. Then he advised I should fit only cylinder 5 with an oversize piston citing that it weighs the same as a stock piston. (This I am having difficulty swallowing. I need some opinions on this). As an alternative, and which will be more costly, he advised he could bore all 6 and go with oversize pistons for all 6.<br /><br />4) He advised the crankshaft is bad. Mine can be rebuilt for 70% the new price. Or, just buy a new one.

Re: Disassembly & Cleaning

He is right about the one oversize piston.It won't vary from the others any more than the variance between a whole new set.<br /> When building a race motor, we carefully weigh every piston and rod. Stock rods will vary much mmore than stock pistons, even if they are not the same size.<br /> I prefer a good used crank over the remanufactored ones.<br /> Sounds like an experienced machinist to me.

Re: Disassembly & Cleaning

OK so I will direct my machinist to go ahead and bore #5 to fit with oversized piston, then hone the rest, and weld the hole.<br /><br />I removed piston pin 5. Noticed some wear on the rod jounal (rod will be replaced anyway).<br /><br />Is there any reason to pull the other piston pins as I twisted each rod against each piston, and checked for any play, and there is no play, except for #3 (how often do you guys see piston pin bearing failures). <br /><br />#3 has some play, and so I will pull that pin also..I assume that bearing got saltwater on it too and that must be why there is some play.<br /><br />Also noted that rod 3's crank bearing is significantly warn, and a groove is worn into the rod side of the rod journal. I am going to replace this rod now also.<br /><br />Now what about the rod-to-crank bearings - am I replacing all of these no matter what or can some possibly be reused?<br /><br />Rodbolt, thanks for the lead re: Bill. I contacted him yesterday.<br /><br />I'm still looking for a good used or new crank...

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ya gonna fix this motor or patch arse it back together so it makes a couple trips ?

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OK so let me get this straight: I'm replacing all rod bearings (wristpin bearings & crank bearings). 10-4, sorry, you stated that 4/13...to check all wristpins. Time to break out da tools again.<br /><br />Now regarding crank bearings, you mentioned replace the bottom, and check the top. Should i just replace top, bottom, and center two, period?, also, sealing rings are to be replaced?<br /><br />Having trouble getting stains off of pistons: Pistons Soaking in gasoline then brushing with stiff bristled nylon brush..stuff is not coming off...is there some better method to use.

Re: Disassembly & Cleaning

I did not say what to replace, I said take it down for inspection.<br /> if the rollers show no pits or rust marks odds are they are ok for reuse.<br /> but they must be clean and inspected with good lighting and a magnifying glass.<br /> the bottom main has to accept a radial and an axial thrust load and gets replaced regardless, rodbolts get replaced anytime they have been torqued.<br /> thats why I said contact Bill, if the crank he has will fit its got all the bearings and such. it scuffed #1 and was replaced under warrenty and now the old powerhead is gonna be parted out.<br />the block assy is a low hour OX66 motor that looks good.<br /> stains dont worry me, but if you wish combustion chamber cleaner and crocus cloth work well.<br /> after all the machining is done replace the fuel recirc check valves as they will be full of machining debris.<br />what your assembling is a high performance engine that is designed to run at or near its rated output for hours on end. if assembled correctly and all the tolerances are held just like the engineers plan, it will do it.<br /> but just like a nascar motor if it has a weak link you will find it.<br />that 3 dollar rod bolt that was not replaced can cost ya 2400 in damage when the head pops off.<br />and we wont even get into bad gas.

Re: Disassembly & Cleaning

Thanks RB. Understood.<br /><br />I did contact Bill, and basically he didn't sound too interested in tearing down the block for the crank. Same with new parts...he was saying that he'd have to rebox them and all, which would cost time...... he just didn't seem that interested. Maybe I should call him back and discuss it a little further...<br /><br />Friend that I work with was shocked that I still plan on using the block after a corossion hole was found. My machinist will weld it, but it seems feasible that other areas of the block could be close to making holes too. I'm not sure what to think about my block at this point. I have not told the machinist "go" yet.