Debris in crankcase - what got destroyed?

I've got the engine on the bench for a new head gasket to address a persistent oil leak, and some new engine studs. I got worried some dirt and gravel might have fallen into the crankcase while I was cleaning it, through the engine stud hole that goes all the way through.

So I pulled the oil pan, and this stuff immediately fell out.









Looks like something got tore up, and the oil pump pickup has a lot of debris in it too. There weren't any strange sounds or other symptoms last time I had it running, that would have indicated anything was wrong. Any thoughts?

 

That looks like the primary chain guide, or damper, as it's called.

 

OK, I can see in the haynes manual that it probably was the starter clutch guide, with the big angled teeth. The book seems to say it's not a part that gets much wear, so I wonder what happened there.

 

Yep, starter chain guide............that's what they do when they fail. Typically doesn't happen until you get 40K+ miles on the engine.

Lucky you already got the engine out, since you will have to do some major dis-assembly to access it for replacement..........even luckier that you discovered it now!

 

Haha yeah lucky me. Wish I'd gotten a more comprehensive gasket kit, I didn't anticipate getting this deep in it... a few new studs, gaskets and stem seals (thanks Len!), valves lapped and reinstalled, and then was THIS close to buttoning it all back up.

Been reading up on it, looks like the only way at it is for the crankcase to come apart.

http://xjbikes.com/Forums/viewtopic/t=1 ... rt=30.html

What exactly does the guide do? I'm sure Yamaha didn't just engineer it in there for kicks, but it looks like there was some debate as to how critical the guide really is to the hyvo chain. And if anyone has tips for the crankcase job, will certainly be most appreciated

 

Hi Doctor, The Hy-vo is like any other chain that is under a load, (in this case it drives the alternator and allows for torque from the starter motor to get the crank moving when starting), it stretches. The guide as some call it, protects the inside of the upper case when the chain gets too loose. If it weren't there the chain would wear a hole in the case. This chain does not have a tensioner.

 

What happened?
30 Years passed.

The best guess it that it has succumbed to the passage of time.
Deteriorated.

If the Bike "Sat" and the Guide "Dried-off" ... that, probably had something to do with it.

The small fragments usually make their way over to the Shift Forks and prevent the Gears from exchanging.

 

Wow... I looked at the picture and saw the gunk on the pan. I was gonna say it's mostly gunk that passed through the engine through the years. And then I saw the debris...
Only tips I can give about the engine are my own observations: do it thoroughly. When I opened mine, I discovered rusted-out dowels and over-torqued bolts. And use precision tools. Loose-fitting tools don't get the job done, and cause more stress than relief.

 

Since you are giving it th worx, you could view this as a good thing, especially as it was doing a good job that had you find th guide bits....unlikely to happen again for you.. and it just musta been Fate

 

For a Fistfull of Dollars, you can renew the starter clutch, shifter springs and rear seal to put all those trouble areas behind you for another 60,000 miles.

 

Thanks for the input, all. Started pulling covers off last night. The center allen bolt holding on the timing plate (crankcase left side) is stuck fast... not a good place there to use a torch to unfreeze it, either. About to see if an overnight PB Blaster soak did anything to it.

I can certainly appreciate doing it thorough, while its out and possible to get at. Reading up on here shows this certainly isn't the first bike this has happened to. Fistful of Dollars lol... think that there's a good name for this bike. We'll see how far this years tax refund gets her... (rolls up sleeves)

 

Just finished getting it apart tonight. Had to track down a clutch holding tool from the area Yamaha place to get the center nut off the clutch, then managed to rip the threads on the alternator rotor pretty good trying to pull it off before I figured out what I should have been doing. After that got sorted out it was pretty straightforward, the cases split quick.



Primary chain guide stub



Chunk lodged in the gear shift mechanism. lol this could mean this bike is actually capable of fifth after all



time to get some parts ordered, but right now pretty stoked i got this far.

 

Four out of five ain't bad !!

Hey - did you read the part where there's a place to put a dab of sealant on the cases upon re-assembly??

Supposed to be pretty important - follow the book, and good luck !

 

I got engine internals for sale if you need any. Multiples of everything. Send me a PM or give me a call - 215-622-1844. That goes for anyone else.

Chris

 

And even more importantly, the type of sealant, and where NOT to put it? Be sure you follow the book carefully.

 

Still digging at it and putting together what I need to replace. The rubber grommet separating the middle gear compartment was missing, so will get replaced. Also not present was engine stud #39 that runs through the starter and both cases.

And whats the policy on starter chain oil spray nozzle wear? It looks like theres supposed to be a locating pin, but on this one its broken off. There's also some wear on the protruding side - caused by the hy-vo chain?

 

Bearing housing keeps the nozzle from slipping out, but the pin keeps it from sliding further into the case. Maybe you can tap it with a drill bit and epoxy something in there to keep it in location?

 

First time posting a pic. Let's see if this works. Here's one of a few I have.

Also here's that other part you found in engine.

 

Sorry for the crappy pics. Lighting was bad in there.

 

Erman: How's your engine teardown turning out? It sounded like you got into it around the same time I did.

LETitRIDEparts: Thanks for the offer, I just put ordered replacements though. It seems like the chain guide is such a high-fail component that it makes sense to replace it with a fresh one. Certainly curious about the condition of that oil spray nozzle, does yours show the same sort of wear on it too? I'm getting the impression that they're always found to be sort of chewed up coming out of an xj engine... http://xjbikes.com/Forums/viewtopic/t=2 ... ight=.html

 

Doing fine compared to the amount of time put into the work, I guess.
The engine is still in parts, and will be until I get around to order parts from Chacal (prolly today).
Still not started on the planned sodablasting of the engine case internals (the exteriors are sandblasted to create sticking for the engine paint).

I did manage to manhandle the engine a bit trying to separate the case, because dumb old me forgot the one bolt inside the oil filter distro joint. Need to mold some metal onto the engine cases before putting them together.
All oil seals and o-rings need replacement, same with the chains and the primary chain guide (which apparently broke in 3) just to be sure. If all goes well, she'll hold for another 80k km...

 

Yeah the pics don't do them justice. That's just gunk on the guide. I pulled it out when I cracked the engine, remembered your post, and snapped a pic real quick. I see your point on the new stuff though.

No it's not chewed up on the end. It does sit right in between the primary chain securely. Yours was probably just because that little tab fell off and it wiggled around or something. None of the ones that I have pulled have been like that, but maybe I just got lucky.

 

UPDATE got the new guide installed. There was lots of grit in the case to be cleaned out. Also some slight wear on the gears near the around the forks, but nothing major, and the starter clutch was in surprisingly good shape. So i got the cases back together. Used grey Permatex gasket maker via XJ4Ever - good thing there was a large tube of it, because after applying it to the mating surfaces on the top and bottom cases (taking care to keep it 2-3mm away from bearing surfaces and central oil passage, per the manual) the cases totally refused to come together. So we stopped until I could clean off all the goobered up Permatex, then cleaned up the locating studs so they would locate smoother, and the second time pressed together just fine.

also new paint


cause thats what you do when you pull an engine right?
So now, just need to wait for the rain to stop to finish degreasing and painting the cases, and do something about the stripped threads from one of the valve cover bolts in the head. Then reassemble, recheck valve clearances since lapping, and so on

 

So I guess your recommendation is to apply a thin strip, since it expands when joining. And to bring them together fast?

 

Yeah a thin strip for sure, since both faces get covered, and too heavy a coat squishes out everywhere.
I brushed it on evenly with q-tips to get close but not too close to the tricky spots.
However, it skins over pretty quick and there's a lot of area to cover - my mistake was not checking to see if the halves were going to hang up anywhere when refitting, should have made sure before starting that the locating studs were clean and not too tight, and the plastic camshaft chain guide was seated where it's supposed to be.
The shifting fork located on the upper gear easier than we would have thought- my assistant and I just made sure it was angled up right, and then watched between the cases through the top that it engaged correctly.

 

God I work slow, but here's some video proof of the motor reinstalled and running again as of yesterday: http://youtu.be/85tH0ufeLx0

so now:
-valves checked, in spec
-Went through the carbs again - not sure how i messed up the float settings so bad the last time, but now they're right and looking forward to that and air leaks not being an issue anymore
-No oil leaks so far, watching for drips like a hawk
-vacuum synced- sounds good overall, can idle down and stay idling at just over 1100 before it seems to struggle but hasn't died so far. might double check it. also plug chop next up
-vacuum syncing left the new silver paint on the jugs a nice toasty brown! hoping its at least good and baked on now.
-Where does the engine ground connect to? Can't find it in the manual, I had it hooked to rear brake foot pedal switch screw (just discovered that switch never came with this bike - i guess next thing to track down)

remaining stuff to work on:
-something smashed the exhaust in this bikes past life. I tried getting it patched with baling wire weld, but stills got a small leak. no cheap fix there.
-headlight won't turn on with the bike unless manually momentary-contacted. trying to figure out a good fix.
-brake rebuild, fresh tires, turn signals, all the important stuff that isn't so important when the engine is in bits

 

That video shows me how I WANT me engine to look (if I ever get around to painting it). Not quite midnight'ed but lots of black with alum/silver highlights

 

real nice paint job man.

 

+1

 

wow thanks a lot ya'll, I'm pretty stoked about how the paint turned out. Filing the fins is a breeze since the aluminum is like butter, and the whole thing looks beefier when you can offset the jugs color IMHO... I just wish it hadn't chipped up so bad in spots while we were wrestling it back into the frame. pre-aged i guess

anyone know where the engine ground connects? second wire from right on the very rear of the engine?

 

the engine ground is simply a heavy wire that bolts from the back of the engine to the frame. Use any available engine bolt that will allow the wire to reach the frame. But otherwise, yes, it bolts to the back of the engine.

Dave F

 

The OILER gets Pushed into the Case

Then, ROTATED until it LOCKS.

Carefully remove the O-ring and visit the Plumbing Section on a well-stocked ACE Hardware Store.

They should have O-ring in ALL Sizes.
Find one that's just like the Original.
Also get one that the next size up with same ID.

Use the tightest fit.
Get Viton if available.

 

Well, things were looking promising. Rechecked the vac sync, sounds like a sewing machine now. So I put some gas in it, ran the bike around the block twice, and when I got it home spotted an oil leak I'd been dreading :x

A lot of oil is collecting in the drive shaft boot. Hard to tell where it's specifically coming from, but the outer o-ring of the middle gear output was replaced so I'm guessing its from the center gasket.. . can I get to it without pulling the engine again? The rear wheel has to come off for a new tire, that should give me room to access it right?

bla. pic of it in it's near glory, at least

 

If oil is collecting in the boot, I'd say it was the output shaft seal. There is no real way oil can come from the middle gear other than a seal leak or a crack in the case . If your bike has a lot of miles on it then that is the most likely the cause. The repair is a bit daunting, it means removing the swing arm and the drive shaft flange, but once those parts are out of the way you shouldn't have any problem changing the seal.

 

Did you remember to put all the o-rings back onto the u-joint?