Help! I've just been piston slapped

[Matthew A.]

Useless info:
[<The tell tale sound of rattling pistons while we were <on the water gave us a couple of hours notice that she <probably wasn't going to get us all the way home under <her own power. Unable to overcome the increasing <friction between cylinder wall and ring with just a half <mile to go before making the channel entrance, she <screeched her last breaths and died.

<Services will be held for those wishing to attend. Being <that she was an outboard motor there will be on <course...a wake after the funeral.]

<Message body> read here:

I would rather not get into checking crank bearing play...boring and ring gap sizing ect ect...What I would prefer to do is to obtain a long block...crank, pistons, rings installed and just have to bolt on the external frills and lace such as manifolds, carbs, head, electrical, ect ect.
Having removed nearly everthing but the block from the motor leg I find I cannot get the flywheel loose. In the past I have attempted to remove the flywheel and couldn't despite attempts at heating the flywheel, soaking the flywheel crankshaft nut with penetrant, banging, cursing, cranking, cursing some more. I have already bent one puller and broken one puller trying to remove this flywheel. Does anyone have any tricks of the trade they'ed be willing to share on removing stuck flywheels as well as helpful tips on removing/replacing the powerhead on a 1988 85 hp U.S Marine Force O.B. Such knowledge is and shall be greatly appreciated.

 

[Frank Acampora]

Re: Help! I've just been piston slapped

I have had one or two flywheels that I had to beat the sugar honey iced tea out of. It seems to happen when the key rusts. anyway, if you were using a three jaw puller, this is a better tool. Make sure you fabricate the plate out on 3/8 to 1/2 inch steel. Put an aluminum block between the crankshaft and the puller screw so as to not mess up the threads. Torque down hard on the screw and rap sharply on it with a three pound hammer. If it doesn't come the first time ,torque further if possible and rap again a few times. This puller will not bend! you will strip the three holding screws first.

 

[Frank Acampora]

Re: Help! I've just been piston slapped

I'll try again. If this doesn't work, somebody tell me how to attach a photo

 

[baxtr]

Re: Help! I've just been piston slapped

you have to "host" the pic on some other site, your own webspace? or someplace like photobucket, then link the photo to that address.

I used a harmonic balancer puller to pull off my flywheel on my 125. I did have to drill and tap the 3 puller holes to accomodate the bigger screws that came with the puller because the smaller holes on the flywheel just stripped right out. I did just what you said though, torque it down, tap with a hammer, torque some more, re-tap, torque, tap torque, tap....................................torque, tap and finally it fell off. It did take a while though.

 

[Frank Acampora]

Re: Help! I've just been piston slapped

If your flywheel is stuck that badly, chances are that the studs holding the block and match plate to the mid unit are stuck also. There's another fun job! Big screwdrivers will not help! I use tire irons and hammer them in between the pry tabs and hope like hell I don't break them.
Any way, to remove the powerhead you must first remove the rear mid leg shroud (the water comes out of this one). It is also much easier if you remove the lower shroud (The hood sets on this one) In order to do this, you must remove the electronics. So a complete teardown is necessary.You must also remove the carbs and shift arm: it makes it easier to get at some of the bolts. There are (6) 9/16 head bolts in the front holding the match plate and (6 ) 3/8 studs with 9/16 nylock nuts in the rear holding both match plate and block to the mid leg. The rearmost stud is shrouded by two webs on either side and you must use a thin walled 12 point box wrench to remove this one. You cannot get a socket in there. The back of the block has two pry tabs. If you pry and the block comes loose but will not come up you have missed one bolt --look to see which one you have not removed. When the block comes up there is an exhaust tube attached to the match plate. You must wiggle the block to free the flange on the exhaust tube-- it usually catches on the top of the water tube. The bare block, crank, and pistons weighs --I don't know-- Maybe 80 pounds so you will probably need some help to lift it.

 

[JUSTINTIME]

Re: Help! I've just been piston slapped

I'll try again. If this doesn't work, somebody tell me how to attach a photo

easy

u need to write in HTML code
upload Ur pic to photobucket.com
scroll down pic and copy the URL code
then insert the copied URL code in-between (where the null is) when u click on

but click down and use bbCode not HTML or plane mode

 

[Frank Acampora]

Re: Help! I've just been piston slapped

 

[Matthew A.]

Re: Help! I've just been piston slapped

Hi Frank,
Thank you for the tips on removing the flywheel. Currently, aside from leaving the lower unit in one piece, I have the entire outboard other then the powerhead w/flywheel and what's under it, disassembled. The tear down was extremely easy. Only breaking off one bolt head that luckily didn't slow me down any. I figured now would be a good time to beat out the steerings hinge pin since the pin no longer pivots. I'm also going to drill and tap the zerk fitting locations. Why Force decided zerks should be pressed in instead of threaded is beyond me. Perhaps had the zerks not "popped out" when trying to grease them the steering pin would not have siezed from lack of grease. Hmmm, I wonder?
Anyways...I plan on obtaining a rebuilt powerhead instead of doing the work myself. To me the $1500 or so dollars for a rebuilt powerhead is worth not having to deal with trying to locate the parts as well as determining what's worn and what's not as far as crank, bearings, cages, ect. ect. go. I must say that there is real beauty in just how straight forward and simple this motor is in design. I mean it just couldn't get any more basic. Gotta love it.
Oh by the way...nice pic...:} lol just kidding. I do very much appreciate the effort though. ty

 

[JUSTINTIME]

Re: Help! I've just been piston slapped

looks like u did not copy the URL

 

[Frank Acampora]

Re: Help! I've just been piston slapped

1500 Is a lot of money. You will spend about ten hours to do it youself and save quite a bit. New pistons from WISECO cost about 80 bucks and come complete with rings, wristpins, and circlips. You need to buy a bearing kit for each piston at 13 bucks each.

You do not need to replace good pistons as the replacements are balanced to factory weights. You do not need to bore out any liners that are not scored. Boring around here costs about 40-60 bucks a hole and any good auto machine shop can do it for you. Gaskets are available and the kit should not be too expensive.

The only fly in the ointment is if you have scored the crankpins. Crankshafts are not repairable and new ones cost a lot. However, a used one out of a junker is cheap and serviceable. I don't think they ever changed that crank. one out of any late model Chrysler or Force -- any three cyl. will fit.

It is worth at least tearing down the engine to see what the damage is.

Besides, if you do it yourself, you can port the block (square and streamline the exhaust and bypass ports with a Dremel and carbide bit). If you are careful, you can gain 5-10 hp per cylinder. Then when you run the engine you can have the pleasure of thinking "I did that."

Go to Chrysler crew and join the q&a forum. Then go to group photos and look at Frank's boats. You will see an example of porting a three cyl.

BTW: Remove the flywheel before you remove the block;it's much easier that way. And it helps if you wedge a tire iron under the rim while you pound on the center bolt of the puller. Send me your email at TonyonMemory@yahoo.com and I will email you a photo of my puller.

 

[Frank Acampora]

Re: Help! I've just been piston slapped

If the pin you are talking about is the steering swivel kingpin, this never pivoted. the front cap on the lower motor mount holds it tight to the motor leg, and it is a light press fit in the front shroud. Get a screwdriver behind it to separate from the leg and tap it out of the front motor cover. Use somthing almost as large as it; the center cap is just sheet metal

Inside the engine clamp mount (swivel bracket) there are two plastic sleeves on the kingpin. Most of the kingpins I have removed came out with light to forceful tapping, but I did have one that I needed to get medievel on and I destroyed the plastic sleeves. They should be available at mercury dealers.

If you are talking about the tilt pin, that is a 1/2 inch carriage bolt and does not swivel in the motor clamps. Some of them are a real pain to beat out. Just be sure not to peen the threaded end.

 

[Matthew A.]

Re: Help! I've just been piston slapped

I was referring to the kingpin. Unfortunately, to remove it took a good half hour of heating the swivel bracket and then using a 3 lb. sledge to bang it out. I too damaged both sleeves in the process. The king pin had quite abit of corrosion where the nylon sleeves came into contact with it. This motor...boat as well I don't think ever saw any sort of care before I got my hands on it. Luckily though, I don't think the previous owners put that many hours on it either.
As far as damage to internal parts goes, there is some scoring on the upper circumference of no. 1 cylinder. All cylinders as well as each piston have scrapes. However, the scrapes along the piston skirts are relatively light. One can even still see the cross hatch pattern on the cylinder bores and there is no noticable ridge at the top of each cylinder bore. I had performed a compression check on the motor prior to the trip before our last. The motor just didn't sound right to me. Readings for each cylinder read about 142-144. As I mentioned earlier, damage to the cylinders and pistons from piston slap is minor. Yet, that's what worries me considering that moments before the motor siezed as we were nursing it home, it did so with a muffled screach. From how light the scratches are on the cylinder walls I am wondering if what caused the motor to sieze was due to a rod bearing. Before I resorted to rowing the boat to the trailer I figured that since the motor had cooled down she might start. Though, she turned over easily for me, she wouldn't start. I didn't press it.

Also, thank you for your tips on removing the flywheel. I had to bang on it like hell...but it finally came free. Rusted key. Because of how hard it was neccessary to strike the puller bolt and how many strikes it took would you know what the chances are that I may have damaged the the upper and lower crank bearings?

One thing I noticed while peering at the crank thru the intake ports is there is carbon build up on the bearing caps for the rod ends. Something I didn't expect to see considering how they get sprayed with fuel/oil on the intake. Is that normal on some engines depending on care?
Doing a little bit of porting work was defineately something I had been thinking about for sometime. Especially now that you've got me considering doing the rebuild myself. I'll let ya know what I find as far as the crankpins go.
Thank you again Frank for all your help. It is very much appreciated.

 

[Frank Acampora]

Re: Help! I've just been piston slapped

The bottom bearing is a roller bearing and you cannot damage it by pounding on the crank. The top bearing is a ball bearing. They are difficult to damage but it can be done. After you get the crank out roll the bearing by hand. It should roll slick smooth. If you have brinelled it, You will feel the dents as you roll it. I feel that minor roughness will not affect operation or service life but thats my judgement call on my engines. This bearing is difficult to get off: you need a press and a special bearing puller that gets under the race. A machine shop will do it cheap. The new bearing is in auto supply stores or bearing houses. It is out of the rear end of a Ford. dead standard. 25 bucks. To install it use my trick of heating over a 100 watt bulb for 10-15 min. It will slip right on.

Judging by what you say the condition of the cylinders are and the screech before failure, I would venture to guess that at least one of the big rod end bearings has seized up. The big ends of the rods are almost always clean. On Force's, some are painted black but they should be shiny. What you saw as carbon would probably be debris from disintegrated rollers and cages. If that is indeed the case, then the crankpin is most certainly scored as would be your rods.

Just a note on rods: These engines use what is called cracked cap technology. after hardening, the big ends are broken. They break cleanly but on an irregular line. So the caps are not interchangeable. You must install them exactly as they came off. The big end of the rod is a bearing race and the crankopin is the inner race. In between are 16 rollers held in place with a split cage. Because the rollers ride on the races, there are grind marks on the outside of the rod ends. You must align the caps so that a pencil point or dental pick glides smoothly over the grind marks. In most cases this is not a difficult task.

If this is the case and you have trouble getting the parts, contact me at TonyonMemory@yahoo.com. I have extras.

BTW the ten hours I quoted was for both tear down and rebuild. You're halfway there already. And look at it as an adventure. I had a lot of fun rebuilding the first one I did. I still do. And the first time I fire up a rebuild in the driveway I still get a sense of wonder and contentment. I DID THAT!

 

[Matthew A.]

Re: Help! I've just been piston slapped

First, I wish to thank you for all your time and your help you have given me. It is very much appreciated.

Upon opening the case to reveal the crank I noticed the rod end bearings and cage for no. 2 cylinder were chewed to the point to where the rod end moves around on the crank about an 1/8 inch in two directions and 1/16" side to side. Some of the needle bearings were obviously missing as was parts of the bearing cage. The cranks main bearing that is next to the no. 2 rod bearing developed a crack with a gap of about .015" to . 020" across it's race about 1/4 inch from the bearings intentional crack location. The bearing also appeared to possibly have spun it's race. As there are score marks on both cases where the bearing is seated. The rod end for no.2 cylinder must have endured tremendous heat prior to it's failure as there are metal shavings actually fused to rod end. This would help to explain why the top of no. 2 piston was completely bear of any carbon deposits. I guess if one really wants to remove carbon deposits from the combustion chamber and piston and give your piston tops that bead blasted appearance as my no. 2 piston has, nothing beats the scouring affect of tiny metal shavings. Just as long as one doesn't mind the effect these shavings have on other parts of the engine. LOL I had a feeling that the developing engine noise I swore I was detecting that sounded as though it was emminating out one of my carbs, despite my friends protest that I was hearing things, didn't sound like piston slap to me. Is it possilbe what I was hearing was excessive rod end play? At any rate, for what it's worth, the rest of the engine such as No. 1 and no. 3 piston skirts showed only the slightest wear and scouring. Their rod end bearings and cages also appeared [at least to my untrained eye] to be in good condition. No gouging, missing parts of cages or mangled needle bearings as well as no bits of metallic looking substances "fused" on their rod ends. LOL.

Good news is that I got the 1.125" aluminum king pin w/ new nylon sleeves/bearings installed today. Despite losing my boats non-affectionately named "auto-pilot", I can't wait to experience what it's like to actually turn the wheel easily and without having to use 20 to 30 lbs. of torque trying to get the wheel to turn. Woot woot!

Might I ask if you would be willing to share your thoughts or prehaps have any recommendations as to whether I should pursue with the rebuild myself or might obtaining a "core" refund on a short block be more appropriate?

Once again Frank, thank you for all of your help

 

[Frank Acampora]

Re: Help! I've just been piston slapped

Well, it should be obvious by now that I enjoy b.s. ing about engines.

What you heard was definitely the big end bearing going and then gone. What happened is the constant pounding wore a groove in the top of the rod and probably also elongated the cap, so now you have a useless rod with an egg shaped hole. You didn't say so but at this point I would bet the ranch that the crankpin is also damaged.

Since I have never bought a rebuilt block, I don't know if a trade in is offered by anyone, but I believe a new block costs about $800 so there should be some trade value there. Look for more in your email.