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Need help with Roller bearings. 1985 XR-2 Marathon Magnum

Waycup89

New member
Hey all,
I have the power head a part as I'm going to replace the bearings and rings. Pulling the caps off the rods, the roller bearings fell out, making me think they were just all wore out. The parts page only shows bearings as part of the cage, yet you can order just the roller bearings. I can find (ebay/not from dealer) the bearings not in the cage, but I was just wondering if the part was updated, as it is a lot less of a hassle with the caged bearings vs putting on the bearings one by one into the cage.

I did buy a manual for my engine, and it doesn't really say one way or another. Does show the bearings not being a part of the cage-but again I don't know if the part was updated.

To get to my engine, use serial number A167987.

Thanks for the time and the help!
 
It would be normal for those bearings to fall out.------It does not means they are" all worn out " either.-----Think about if they were " worn out " you would need a crankshaft / rods too as they are the inner and outer race for the bearing !!
 
It would be normal for those bearings to fall out.------It does not means they are" all worn out " either.-----Think about if they were " worn out " you would need a crankshaft / rods too as they are the inner and outer race for the bearing !!

Yeah, no 5 and 6 loves are kind of worn/piston flattened the bearings. What I wanted to clear up, was can I buy all new bearings seated in the cage, or should I just replace the roller bearings separately and whichever cage sets are bad.-prefer to buy the seated bearings/easier to work with.
 
How about a pic of the crank with the flattend bearings....

Here ya go. And sorry meant my rod bearings journals. Number 6 piston gave way, flattened both top and bottom bearings on cylinder 6, started to effect cinder 5. Replacing both pistons and all bearings, just the bearing question still stands.

Umm... maybe my phone isn't uploading my images currently, hold on...
Resized_20190428_184528.jpg

There ya go!! Sorry had to resize the image. Annoying.
 
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And you are going to use that crankshaft again ??------Are you selling the motor or keeping it ?------Many folks here would say that crankshaft is SCRAP and so is the connecting rod.
 
And you are going to use that crankshaft again ??------Are you selling the motor or keeping it ?------Many folks here would say that crankshaft is SCRAP and so is the connecting rod.

Don't know till I try, going to try to clean it up and put it back together. If it runs sweet, if it doesn't or too high of a difference in compression then I'll be parting the power head, possibly the lower unit as well, and getting another.
 
Any more pictures of the connecting rod bearing surface?----Pictures of scored pistons ?-----Picture of cylinder walls ?
 
Any more pictures of the connecting rod bearing surface?----Pictures of scored pistons ?-----Picture of cylinder walls ?

Here's some more pictures. Can see the piston that gave way. Honing all the cylinders out. Can also see what I mean about the roller bearings not being seated in the cage.

Posted another post about a hole in the bottom of the cylinder I'll have to weld (was advised). Better then the 'Just JB weld it advice I've gotten-their defences is it's not seeing a lot of pressure or heat there.

Really, now just curious if I can replace the bearings with updated bearings seated in cages or do I keep my cages (as new cages are near Impossible to find) and only replace the bearings?
Resized_20190504_164406.jpg
 

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It might be. The end cap bearings look like they were failing, worst part of the crank. It polished out pretty well, Mic'd it and everything is still good. Still need to mic the cylinders.

And I am replacing the whole piston set on cylinder 6 and 5. New bearings for everything else.

I kind of have an idea of how to fix everything now. Still unsure about the bearings. Backyard mechanic. Lotta of hope and tricks learned from old timers.

I'm curious though, about how much pressure is in the lower unit? That is all aluminum, could I possibly use a punch to close the gap/get it to where no light is shinning through?

Thanks all for the time and advice!
 
That motor uses caged bearings on the rod big end - if you want to put it together I hope you kept the end caps with their rods, they need to be aligned exactly.
Here's a page that should help: (note the CAUTION)
crank-condition.jpg1975crankshafts.jpg
 
I've seen cars go out the door at a shop in worse condition then what everything currently is. Well, minus the punch.. This project has been more time consuming then anything else/waiting on parts. Don't mind having to figure stuff out, just not a big fan of waiting to get something done.

Also, in another two years/even another year, it wouldn't be a problem for me to tear the head off and and due what I still need to do. Will have more money to work with then. Can only work with what I currently have.

There's right for the average person that doesn't have skill or time to get into a power head. And there is also 'it'll do' or 'right enough' for someone who enjoys getting into a power head, and has the time to do it. I do all my own work. Even if I'm currently out 3-400 hundred, and everything lasts this season, then that was a cheap fix for this season, and can fix everything in the off season. Where I live it doesn't really get too cold/from the North anyways so don't mind when it does.

Do appreciate your advice and time.
 
Thank you for those pics!! Yeah, my.manual didn't get anywhere that specific. Actually was told to get a new one, which I am still debating. Do have bore sizes and torque information, so guess it depends on what else information I need.

Tried roller bearings I bought hoping the part number was right ('bit the bullet' so to say for one, it worked out) and I was able to find some information on Iboat about the cages.
Normal wear and tear for the most part except for the journal for 5 n 6, and something else but not getting into that. Used wannabe Emery Cloth already (today actually) and polished everything up.

Thanks for the help! Cheers!
 
That motor uses caged bearings on the rod big end - if you want to put it together I hope you kept the end caps with their rods, they need to be aligned exactly.
Here's a page that should help: (note the CAUTION)
View attachment 20344View attachment 20345

Sorry, replied once but not with quick qoute/long day.

And yes, I do know how to take an engine a part. All my rods and and end caps are marked, all my bearings and caps n cages are all in their own container, labeled further as to which one they came from. Still replacing all of them. Slightly out of habit and to be able to compare or look at possible damage.

Thanks again for the time and advice
 
Hope ya got a good trolling motor or phone service for a tow...…...

Yup, cause with a higher oil mix something barely scored wont last one season. Your right about everything. Oh, and I never rebuilt any engines before. Or seen even more get rebuilt. This is definitely the worst of the worst.

If the only advice you give is to put people down for trying something, then don't. I tore a part a 2 stroke off of 4 stroke knowledge. I may have my moments, but I'm not a ****ing dumbass. When I go out, my brother is usually out in his boat as well.

Just cause I'm not fixing to your specifications doesn't mean it's not going to run. Just because it's not perfect doesn't mean it wont run. Why I'll take old timers advice any day, because they have seen what can or can't go out rather then wasting money and having everything cleaned back up to specs. Yes it would make it run 10-15 years. I dont have that time right now, or money. What I am doing would probably make it run for 5 years, don't even need that long.

Just piston ring overgap alone, can be out (for some) .040 Passed the rec. SPECS!! (Mustang pistons). That's calling the manufacture. Yet, a lot of people rec. Buying new rings.

Thanks for the help. Dont want anymore from you. Cheers.
 
I am a "ole timer" of 40 + years and a former boat drag racer. Good luck at ruining a motor and wasted money, you asked for help but refuse to accept it.
Good day!
 
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