Lean #2 cylinder

Finally getting around to doing some serious work on the XJ1100. Bought it in November & only put around 200 miles on it before winter storage. I'm getting a set of Jardine Spaghetti exhausts prepped & ready to be ceramic coated. When I removed the MAC 4-1 that came with it I found #2 cylinder was running way lean.





I know the carbs were way out of adjustment because the idle adjustment screws on 2&3 had been tightened down as far as they could go. I don't have a compression tester but I'm hoping the valves in #2 are not damaged. The PO didn't put any exhaust gaskets in when he installed the MAC 4-1. Sweet...

To the hopeful, it sure had scary power last year even when horribly maladjusted.

 

My lemon...

I've got zero compression on #2 cylinder. I was checking the valve shim readings and when I put my thumb over the spark plug hole and turned the crank, there was no pressure coming from the hole. Put oil in the cylinder and it didn't help. Looks like the exhaust valve is shot. All the things I've found wrong with this bike because of the PO that I've had to fix.

Now I have to remove the head and deal with this. Where will it end...

Criminy. Yeah I'm whining, I've put so many hours in finding needed parts for this XJ1100, undoing the damage the PO did & never told me about that I had to keep finding and all I keep doing is finding more and more problems, each seemingly more severe than the one before. Nobody I know at all around here to help me with what I'm doing. Thank goodness for the internet...

Lovely. Just lovely...

 

Dude, you got all of us to help you.
There are a lot of good guys here that know what they are talking about.
I bought my bike for $1100 then I went crazy and stuck another $4200 into it to make it like new again and do you know what???
I am glad that I did. I would be willing to bet that I have one of the top 10 bikes in town as for as reliability goes and I would run against any other bike and give any of them a run for their money. It is not only reliable but it is fast... It is better than new. Hang in there... You can do it too.
Just consider that a new bike in the size you have would be at least $10,000 so stick some bucks into what you got and make it better than new. It is possible. Keep going man, you will be glad you did.

 

You may yet find a hole in the piston, hope for the best and prepare for the worst. Read "Zen and the Art of Motorcycle Maintenance" by Robert Pirsig. It will help you get the right perspective for effectively working on an old bike.

Good luck.

 

Don't give up yet!

I am working on year four with my project. At least I found out early that the motor was cooked. After making the decision to pull the motor for major repairs I decide to just go through the entire bike and make sure everthing was right.

There is plenty of help and parts right at your finger tips, and I will start the ball rolling for you.

1100 parts motor - http://www.xjbikes.com/Forums/viewtopic/t=31339.html

May be worth the time to check it out. I have bought parts from him, and have more waiting to be picked up.

Part of the fun of these old bikes is making it totaly yours, at less than the cost of a new bike. I guarantee that you will end up with a bike that you will be proud to ride!

Ghost

 

Deal with it a little at a time.

Do a Compression "Wet Test" and see what is revealed.
You won't know for sure until the Head comes off, ... but you might get away with having a burned Exhaust Valve.

If the Piston was holed you would have had tell-tale signs to let you know.
Like, ... a smoke screen choking the traffic behind you and blocking-out the sun. Plus, a big mess in the Airbox and the Oil Light -- ON.

Sorry you are having trouble.
If things get out-of-hand, down there, I'll road-trip down there and do what I can to get you over any hump.

 

How many miles on the bike?

You didn't do a compression test when you bought it?

How hard did you hammer on it in those 200 miles?

With the plug out, you should be able to see the top of the piston come up through the spark plug hole.

How tight was #2 when you checked its clearances?

I'm betting (hoping) burnt valve over holed piston, answers to my questions above will provide clues but of course you won't really know until you get the head off.

 

Some most kind answers, especially Rick's genuinely wonderful offer although I would not want to ask you to do that.

I don't have a compression tester. The one I borrowed was defective in that it was unreliable. When I went to test the bike before buying, power wise compared to my XJ650 it ran beautifully when cold although it sounded unusual to my ears from the $-1 exhaust it had.

When I took it for a test ride it had all kinds of power and did not show major issues, just tuning issues needed to be done. There was no smoke on acceleration or deceleration with max & zero throttle. It then began to rain & I was in NY where I bought it as it seemed to be running in good shape but needing a real tune-up. Engine seemed to be even but popping under deceleration. With freezing rain coming down, no popping out of gear under acceleration and no oil leaks under the bike & with the bike cold, it seemed pretty intact so I bought it.

When I first rode it when getting home I found oil running from the airbox drain tube & the petcock "Octy" was defective and the floats were oped so the engine had flooded. I repaired the octy and that fixed the fuel leak and I'd run the engine dry when I'd stop so the float valves were not an issue while stopped. I changed the oil twice to get rid of the gas & I put on maybe 200 -300 miles tips as I bought it in late October and it was getting cold. It's been garaged ever since.

I guess I have no choice but to remove the head but I so did not want to do that. Due to a recent passing in my immediate family, I really wanted to get away next week on it and take a long ride.

Oh well...

 

So how many miles are on it? That will at least hopefully give us a clue as to the prospects of what you'll find.

Peek down the plug 'ole and see what the top of the piston looks like as it comes up in the cylinder. I'm betting it's there and all coated white like the inside of that pipe.

I would recommend the following: Borrow (or invest in one, they're cheap) another compression tester, and run both dry and wet tests. I'm betting the results point toward a valve (little or no change in #2 wet from dry.) THEN pull the head; since you can't run compression tests with the head off, and it would be nice to have an idea as to the condition of the cylinders/pistons prior to yoinking the head.

 

Sorry Fitz, meant to answer that. 20K on the odometer.

Last night I did put some oil in the cylinder to see if that gave a difference & it didn't. That might now have messed up a wet/dry test since I added it.

I can crank the engine for awhile from the starter & maybe clear out the oil?

Am off to Auto Zone to get a compression tester.

And so it begins... A Streetcar named Desire...

 

20K is a good sign; it increases the odds that it's just a valve.

Can you see the top of the piston?

What were the valve clearances on #2?

When you turn the motor over (with the exhaust pipes off) you can see the exhaust valves open and close. Does #2 look any different, movement-wise, from the other three?

Fret not; hopefully it's just a valve. Parts will be cheap; one valve, eight valve stem seals, a few o-rings and a head gasket. Then you'll have a nice fresh top end. And even more experience...

 

I got a loaner compression tester that was NIB so I know it's working.

To the good, amazingly the #2 did have compression.

To the bad....

Cylinder 1 dry 100
Cylinder 1 wet 140

Cylinder 2 dry 80
Cylinder 2 wet 135

Cylinder 3 dry 80
Cylinder 3 wet 140

Cylinder 4 dry 105
Cylinder 4 wet 135

I guess it needs new rings or more.

Lovely, just @#$%^ lovely...

I bet the PO disconnected the odometer & this bike has a lot of miles on it...
I wouldn't leave it past him, he Borked everything he touched.

I need a beer.

 

just a suggestion: if you have torque wrenches, be sure the head is securely fastened to proper specs on all acorn nuts (12 on top and 2 on bottom = on a 650; not positive the # on an 1100)

sorta looks like head gasket issues in the center of head with compression only in the 80's near center where cam chain travels. honestly though, I don't know the distinctions between 650 and 1100. could be total different motor setups... sorry. just something I was told when I had similar results a couple weeks ago. took it off, sprayed gasket again with high content copper spray, put it back together and behold my compression #'s are much more acceptable (125-135) across the board

hang in there. I've overhauled my 650 motor including new rings across the board, a new piston, valve job, valve clearance checks numerous times, timing chain issue resolved, carbs fully rebuilt. the greatest feeling is knowing you don't have any loans on it (hopefully) and its your toy. even better when you take a nice ride and people are turning necks or commenting on the reliability of a 30 year old motorcycle you've wrenched on with devotion

 

Those numbers are not all that discouraging. Before you go pulling the head check those valve clearances and torque specs.

What i can say for sure is that there is no burnt valve, or holed piston. There would be no compression what so ever. This may just be a matter of doing the maintenace work to get everything back to into specs. Bad rings would have shown as Rick stated.

You deffinately have a lean mixture on #2, and I would tend to believe that it is more from carbs needing a good cleaning, or air leakage from the shaft seals.

It is certainly not as bad as it first appeared.

Ghost

 

After looking at your numbers, ... If I had to guess what you will find ... is a Worn Condition of the Number-2 Hole.

The Hose was probably running so Lean that it consumed the Oil Sheen on the Cylinder Wall as Fuel.

Without the Top Cylinder sufficiently lubed; the Cylinder and Rings scraped on each-other, ... widening the Cylinder to where the close tolerances were sacrificed and the gasses blow-by the rings.

With the DRY reading well below specs; you shouldn't be running that Engine until you alleviate the condition.

It's possible that you have discovered the situation in time to just deglaze the holes and do New Rings.
But, it the 2-Hole is Scored; you might need Oversized Rings in there.

 

I've got to echo Rick's sentiments. Since #2 IS making some sort of compression, wet, something else could very well be amiss; and unfortunately it looks like #2 might just be in some interesting shape.

Wait until tomorrow; run another set of tests.

Meanwhile; hate to be a pest, I've asked this several times: what are the valve clearances like on #2? #3?

If the valves are seriously out of spec, I'd put them IN spec before I yoinked the head, just so I'd have a realistic baseline to work with, and run another set of tests.

You still need to pull the head and look; primarily because of the huge variations between wet and dry. But I wouldn't do it until I had a better idea of what I'd be looking at.

 

Sorry Fitz, I thought I'd posted this earlier but after taking the shims out & testing again the values came out different than they did the first time. I just went over the shims and gaps an hour ago and this is what's there right now.

Book values in inches:
Exhaust: .008 ~ .010
Intake: .004 ~ .006

Intake #1 = .005 shim is 285
Intake #2 = .004 shim is 280
intake #3 = shim is 280 can't measure, is tight, can slip paper in-between
Intake #4 = .004 shim is 280

Exhaust #1 = .009 shim 285
Exhaust #2 = .008 shim is 275
Exhaust #3 = .009 shim is 290
Exhaust #4 = .006 shim is 290

I so do not want to go into the cylinders right now... Wish I would have found this earlier in the year so I could have dealt with it a month ago...

Ugh.

 

Panic not, Grasshopper.

Rick and I have given you good level-headed advice--- get the valves in spec and test again. DO NOT pull the head yet; miracles do happen.

Fix the valve clearances; then we'll talk after the new compression tests.

Your cylinder walls could have been OVERLY dry ("drier" than normal operating conditions.) The tight valves could throw off the dry test, and if you dumped enough oil in for it to get under the head of a valve, it might have helped the "wet" test.

LEAVE THE MOTOR together; get the valves in spec. Re-test. THEN panic. <kidding>

Go crack a cold one. I just did (Killian's.) Oh, and get a metric feeler gauge, willya?

 

Today I removed the head on the XJ11 to look for causes of very low compression as I mentioned in this post earlier & I had a bugger of a time getting the head off. I had to resort to pounding upward on the head with several different pieces of wood & a mallet. Problem was on the left side of the head, it seemed like it was being held by a bolt but all the nuts were freed.

The problem getting the head off was it turns out the stud between exhaust 1&2 was rusted and somehow the shaft was filled with rust. Doesn't make sense on an aluminum head engine but this stud and the one between exhaust Cyl 3&4 were all rusted. The one between 3&4 came out of the block instead of the nut unscrewing. Below you see how the shaft in the cylinder is filled with rust where the head came off, the stud does not move... It was all I could do to pound the head upwards to force it off. You can see the rust embedded into the threads from the pressuers generated when I pounded the head up & the rust in the channel got jammed into the threads.



Here is a shot of #2 cylinder where the low compression was found:



Here's Piston 1 which cylinder had pretty good compression



Bottom of the head showing the valves:



Here are the valves for cylinder 2 which had poor compression as did 3:



And here's Valves for 4 which had good compression:



I'm going to try and remove the cylinders tomorrow & to prepare, I squirted quite a bit of kroil along the rust surrounding & holding the stud in place in hopes it'll not give me too much resistance.

Any idea why those two studs rusted like they did & more, there does not seem to be enough rust on the shaft of the studs to account for the volume of rust that was in the shaft. Literally there were chunks or compressed rust I found 1/2" long & semicircular where they fell off when the head came off. All from that stud.

Amazing...

Thoughts on the above & anything looking off with the cylinder & valves? I did not see any vertical scorings, anything that looked vertical was in the sheen, not grooves I could feel.

Yesterday I re-checked the compression & Cyl 2 was at 60 dry & around 90 wet so soaking it in diesel fuel didn't make a positive benefit.

Thanks!

 

Look closely at the picture of the #2 cylinder wall; see those "rings" up toward the top? That cylinder has had a "near seizure" at some point in its life; and the chances are good the piston itself is no longer in spec.

If the walls 'mic' out ok, then you may be able to get away with just a new piston and honing. (I'm assuming replacing all the rings on all 4.)

Do not trust the #2 piston.

 

Oh that is bad news indeed. There's cylinders & pistons from a well running XJ1100 that was damaged in a skid I can get so I'll send off for those.

Man, I had no idea this bike was going to be such a hassle to get running right. Bad enough to have to do the repairs but to run into so many unexpected problems getting parts off.

It's going to be a challenge to get the cylinders off with that rusted in section. Soaking it in Kroil to see if that gets through the "rock". I'd picked away at the rust before taking that first photo. If the rust is that packed all along the stud, I don't know how I'll get the cylinder off.

Time to be creative...

BTW, with good pistons & their matching cylinders, do I need new rings? I'm tight on money and need to conserve.

 

It depends entirely on whether you want to do the job once; or possibly have to take it apart again. Until they're fitted and tested, you have no way of knowing the ACTUAL condition of the second-hand components.

Either way, you can't order new rings until you know the measurements on the cylinder bores and pistons, to ensure that "standard" rings will still work.

 

finally got it apart, broke a couple of fins because the rust was so embedded that it was held together like glue

First; the reason there was RTV slathered on the front lower part of the engine below the cam tensioner.
Whoever put the gasket in broke it, the gasket pieces were petrified in place.



I'll post the photos in sequence. There was no apparent gouges to be seen in the cylinder walls. Nothing uneven to touch.
The only denting/impression AI found was on #3 piston which had what looks to be like dents between the top two rings
from maybe poor handling in the past? No marks matched it on the walls of the cylinder.

First the cylinders and since all the circumference looked the same, I only took one shot. On the bottom of each
cylinder where it sinks into the crankcase there was 004 marked from the maker. Not sure what that means if anything.

Cylinders


Piston/cylinder 1




Piston/cylinder 2



Piston/Cylinder 3 (note dents between rings)



Piston/Cylinder 4



Anything notable?

Thanks

 

Yeah.

It looks like 3 out of 4 cylinder's walls have those "rings" toward the top. That motor seized or came very close.

The "dimpling" in #3 piston is because it began to melt which distorted it. Those aren't "dents" from the outside; it was where the metal started "caving in" as it got soft. Kind of like "sink marks" in a molded plastic part.

You can't tell anything about the cylinder walls by looking. Look in your manual, it should show you how to measure the cylinder itself. That's where you start; top, middle and bottom dimensions on each cylinder, as shown in your manual.

All we know right now is you need a new set of pistons, or at least 3 from the looks of the walls.

 

Let me ask all you guys a question. How is it that the #2 pipe is snow white yet all the combustion chambers are the same color in fact #2 and #3 look the darkest.

 

Waldo, I just discovered a possible answer 45 minutes ago I think, maybe?

Took the heads and the cylinders to the machine shop and he wants me to remover the carbon at the top of the cylinders and then he'll spec the cylinders (though I knocked off three pieces of fin getting the cylinders to release thanks to the impacted rust holding them in place. If you look at the picture of all 4 you will see one of those broken fins in the lower right.). I also have a set of used pistons and cylinders coming in so I'll take both sets to the machinist and see which one he thinks is closest to specs. But I digress...

I asked him what he thought of the condition of the valves and he said they looked fine but to put some gasoline in each intake and exhaust port & see if any dribbles out & if so, there is the reason for valve work & if no gas comes out then the problem is not valves.

Did the exhaust first and no leaks.

Checked the intake (had to plug the YICS ports) & gas came pouring out of #2 but to the outside of the head. found the gasket for the intake was broken at the inner Allen bolt and was hanging to the inside and the gas was pouring out between the manifold & head at that point. No telling how long that has been like that but whoever put the gasket in did not do it properly. I bet that's why they went nuts with the carb & why the air adjustments were squeezed in as tightly as could be done, nothing they could do would make it idle properly. I never had it long enough to check that out & just rebuilt the carbs over the winter & haven't had it running yet this year.

This bike will be a delight once I'm done but #$%! it's been an unexpected PITA getting there.

 

Because he's sprayed all SORTS of oil, etc., into them during the initial diagnosis?

Those shadowy rings at the top of the cylinder walls are the result of a seizure or near seizure; they're a telltale sign.

One of the first motors I ever blew up had a piston melt enough to stick a hunk of itself to the cylinder wall on the way down; and on the way back up ran into the now slightly cooled and firmly welded chunk and...

The part that melted was right above the piston pin, just like the pic of #3.

This is a motor that either seized, or came very close to it; and it also came very close to a piston catastrophe on #3. I think whatever was going on in #2 was a secondary symptom of whatever the heck happened previously.

Sorry.

 

I didn't know of any issue with the engine till I removed the MAC 4-1 & saw how white #2 was. Till then my only plan was to rebuild the carbs, sync, colortune and clean it up. All the oil & stuff in the carbs was recently to check the compression but the bike hasn't run once this year, it's been minus carbs & exhaust. So the white was from last year when I bought it.

Always something...

 

Thats great news KA1J sounds like you are on the right track! To tell you what I think I am not seeing bad cylinders or pistons or signs of seizure. What I do see is someone had the top end off, that rtv was not done in the factory. I am guessing bike sat and a cylinder rusted someone removed top end but failed to de-glaze cylinders and slammed it together and sold it. Sounds like you found a good machine shop. If you think that was a good ride before wait till you get her right. Now while you are waiting, get the carbs done right bench sync and float levels checked did you replace the throttle shaft seals in the carbs?

 

It's very difficult to look at these photos and say with absolute certainty what was going-on with that Mill.

From the few clues which do have something to say about matters:

1. No.-2 was so Lean it was burning the Oil Sheen and was close to failing.

Notes: The lack of Carbon Deposits on the Piston Crowns, Combustion Chambers and exposed Valve surfaces ... indicates that there was a OVERALL Lean Condition -- Unless the surfaces were previously cleaned.

2. There is a slight Warp letting heated gasses escape between 1 & 2.

3. The Frying-pan look of residue on the Piston Crowns COULD Indicate that the Lean Condition was treated with an additive.

You should have the Head "Overhauled"
Valve Job
Valve Seals
Mating Surface Planed (plained), ... perfectly FLAT.

What to do about the 2-Hole will be bases on how deeply scored the Cylinder Wall is and what condition the other 3 are found to be in after evaluation and measurements.

Looking at the YAM/PARTS Site -- Availability.

Pistons are No Longer Available

Rings are Available in 1st & 2nd Over

 

I'm definitely a novice at the innards of engines though in 69 I built up a Volkswagen bug by myself that turned 11.1 in the quarter at the dragstrip in colchester, CT; it had a VW block, not a Porsche or Corvair engine, .48 IDA Webers, Judson Magneto, full race cam, roller crankshaft & much more but that was 42 years ago & I haven't been into an engine since then.

My gut agrees much with Waldo. I'll go a bit further saying that the engine was opened since assembly and the person who did it was sloppy, rushed and when the engine would not run properly they adjusted it to the ends of carb adjustment and when it would not run properly and was an eternal problem, the PO sold it to me.

Since there were two head studs that were horribly rusted, causing the problems in getting the head off, I don't think the work was done recently and I suspect whoever did the work did not properly torque down the head and that is why those two rusted studs were able to get water down past the cap nut and washer where the water pooled and rusted away as it did. Further, I think the poorly torqued cap bolt was the reason there was compression leakage between #2&3. That the #2 manifold gasket was 1/3" off and leaking at the Allen bolt and the gasket was so malaligned below the CCT tells me it was a novice who did the work. I only hope they did not do anything lower in the engine and that I caught this ugly in time to fix it.

I don't know who did the work but I've been angry with the PO who sold it to me in that there was so much that was strapped together that was hidden & most of the electrical boxes were held shut with strips of what looks like inner tube rubber and it was used as wire ties all over the hidden parts of the bike and that there were those same rubber thingies that were hanging off the brake & clutch levers and the leather bags like a Maxim ghetto cruiser that it likely was him to have had a bunch of it & he used it liberally everywhere.

I have to figure out how to remove the pistons, guess there's a circlip that holds the wrist pin in there & I have to figure how to get that out & hopefully the wrist pins won't be a problem at that point. I'll take both sets of cylinders and pistons to the machine shop and let him tell me which ones to use & then I'll have a light honing & put them back in. As to the heads, leveling the heads and the tops of the cylinders is a right thing to do at this point. If the best cylinders are the ones I just removed, I'll JB weld the tiny chips of broken fin back on for cosmetics as they are so small as to not be a cooling issue.

I've put too much into this bike already and can't afford the price of rings &/or pistons to match them. I just know when I reassemble this bike it will be running nicely, doesn't have to be an all new upper half.

Ugh...

 

The Piston's are Full-floaters.

The Wrist Pin is secured by a simple "C-Clip"

The C-Clip, ... once removed, ... is NOT reused.

 

Don't JB Weld the fins, get them heli-arc'd back on.

 

That may be the show-stopper, my friend. You'll need to measure the cylinders carefully, TOSS the pistons that are in it, and hope your second-hand set is nicely in spec for standard rings. Your current #3 piston shows signs of melting and those stutter rings toward the top of the walls are the telltale signs of a seizure. I wouldn't trust any of those pistons.

But no matter how the piston situation turns out, you're going to need to hone the cylinders lightly at the very least, and then you really should use new rings.

Otherwise you're likely to be right back where you started.

 

If the Fin Damage is "Slight", ... draw an "Eye-pleasing" arc and DRESS the remaining portion to look Un-broken.

Lay a piece of Cardboard on the Repaired Fin and trace a Pattern you can Flip-over and duplicate the chipped-off Fin fragment on the opposite side.

If you think you have done sufficient damage to impede the Cooling area, ... then you should consider having the Cooling Fins (plural) repaired.

In the Future, ... don't Hammer on the Block.

Employ the "Twin Putty-knife Method"

Sharpen ONE SIDE's edges of the Putty Knives.
Tap one between the Mating Surfaces.
Tap the second one, ... right beneath the first.

There will be a gap where the Handles meet.
Squirt-in Lacquer Thinner.
Move Putty Knives to another access area.
Repeat.
Where-ever there is enough room to work.

After the Thinner has had a chance to work, ...
Tap the Putty Knives into a spot you want to Pry.
Work the Tool you'll use to Pry between the two Knife Blades.
Cover with a Safety Rag <<>> Wear Eye Protection!

Pry the two Knife Blades apart.
Don't worry about scratching the Putty Knife.
They act to prevent Tool Marks from marring the Mating Surfaces.

 

Hi Rick,

Truly an excellent description of how to do most cylinder removals. Wouldn't have applied to mine as the studs between 1&2 were rusted solid into the stud tube/channel in the head, the rust had swelled so much there was no releasing the cylinders with simple tapping or incremental wedging a'la putty knife, it would have broken the knife. Had that one been like the other 13 studs, it would have pulled off with very little encouragement. As it was, I had to knock on it upwards for 45 minutes to get it off. It turns out one of the bushings to center the cylinders on the block was rusted like the studs and that magnified the resistance to getting them off.

It is my firm belief the PO had for some reason been into the head & removed the cylinders and when they were retorqued, the proper sequence and values were never considered if ever known (The PO was an absolute idiot). Regardless, I could not use any kind of putty knife to remove these, they were rust welded as tight as well as... well, they were rust welded tight.

There are three pieces that came loose & none of them are large or major pieces. Some high temp epoxy will hold the pieces in place and will look fine and though there's certainly heli-arcing to put them back on, the volume of weld doing that in those tight spaces would negate any benefit of the return of the fin (I went to welding school at General Dynamics to be permitted to weld on submarines).

I'm getting a new set of jugs tomorrow or Sat & will see which one is the best conditioned one of the two and I'll use that. If it's a toss up I'll use the "new" ones and they have no broken fins. Also, I found some rings at a much reduced price so I'll put them in as well. Going to have the machinist do the honing and I'll have to figure out how to get them properly inserted in the head. I'm sure it's written up somewhere.

Do the "O" rings at the bottom of the cylinders have to be replaced? I'm going to make the base gasket out of gasket material & then RTV it in place.

And what does the 004 inked onto the bottom of the cylinders refer to?

 

I couldn't say with absolute certainty; but it's most likely a notation from a Machinist indicating the Cylinder Sleeve Jackets have been >> Bored-out to
.004xx Over Standard.

If that is the case, ... the Jugs have already been Bored to the 2nd O/S.

(If .002 is the 1st Over and .004 ... 2nd Over.)
Its supposed to be Stamped.

Look for Indicators on the Pistons.

The O-rings are a SPEED Feature.
They got fitted to save the assembler time applying a Sealant that would ooze and spoil the build.

There are Sealants available to make the Bottom-end leak-free.
YAMAHA has two great ones.
YAMABond-3 and YAMABond-4
The result will not look as pretty as replacing the "Spaghetti-Orings"
The "Squish" will ooze-out and look undignified.
You get New O-rings with Bottom Kit.

Contact PO and see if he had that Mill Bored-out.

 

Don't think these cylinders are oversize; according to the service manual for the XJ1100 (Page 3-25), the standard cylinder bore is 71.5mm & wear limit is 71.6

Oversize 1 = 71.75
oversize 2 = 72mm
oversize 4 = 72.25
oversize 4 = 72.50

Using my fancy dan $29 digital caliper in #2 cylinder, the cylinder top is cut to 71.58 and the bottom which does not get piston contact, measures at 71.59 I really can't measure that accurately in the middle of the bore but using my grandfathers old fashioned pointy ID calipers and measuring that reading with the digital version I get 71.58 in the middle of piston travel. I'm guessing these are hardly worn original cut cylinders.

I'll try to get the pistons out tomorrow, got to figure how best to hook that clip and pull it out And... how to get the replacement clip back in. I'll compare piston dimensions between the "new" set I'm getting and these originals myself but will get a blessing from the machinist.

Now to figure out how to properly get the pistons back into the cylinders...

Kinda wish I'd never checked the compression...

Ya...

P.S. As to contacting the PO; after buying it from him, he has never returned any of my calls. I wanted to know if the original exhaust was still around and a few other questions. Silence, nothing, nada... SOB

 

"Hold" one end of he Clip from rotating.
Use a "Sharp Pointed Tool"
(Ice pick, Awl, Screwdriver grinded to a point, ... )

Jimmy down-under the other end and lift it out of the Groove.
Once you get it lifted ...
You can:
Keep prying with the Tool and "Let it fly"
Get it started and grab the little sucker with Needles.

You don't need to be nice, ...
Them babies are "One-timers"

ALWAYS use NEW ones.