Installed cylinder.

[movenon]

Starting to go back together.  Slipped the cylinder back on after honing and new rings.  A bit apprehensive installing it myself but it went on smoothly. Took me 35-40 min. to install. Just took it slow and forced nothing. Tapped it on with my hand.  Put the pistons up (2&3) lowered the cylinder, rocked the piston tops to the rear starting the rings into the bore camfor then with a small dull screw driver or fingers guided the ring in while tapping on the cylinder with a light chopping motion using the side of my hand.  If I felt any resistance I just did an inspection of where the ring was hanging up and "prised" it into the bore camfor.  Patience and no forcing are the words.

As a note after honing I dressed /polished the camfored area at the bottom of the bores with some 400 grit wet or Dry just to make sure the area was smooth for the rings to slip into.

Being interesting to see how Yamaha installs them on the production line.



George

[Arnie]

George,

How many miles (or kms) were on your engine? How badly worn were the original rings?
From your statement, I believe you replaced ONLY the rings, and did not go to OS pistons, right?

No idea how the factory fits these things together.
I've previously done it both your way and with 4 ring compressers, but not on an FJ.

Arnie

[ribbert]

Starting to go back together.  Slipped the cylinder back on after honing and new rings.  A bit apprehensive installing it myself but it went on smoothly. Took me 35-40 min. to install. Just took it slow and forced nothing. Tapped it on with my hand.  Put the pistons up (2&3) lowered the cylinder, rocked the piston tops to the rear starting the rings into the bore camfor then with a small dull screw driver or fingers guided the ring in while tapping on the cylinder with a light chopping motion using the side of my hand.  If I felt any resistance I just did an inspection of where the ring was hanging up and "prised" it into the bore camfor.  Patience and no forcing are the words.

As a note after honing I dressed /polished the camfored area at the bottom of the bores with some 400 grit wet or Dry just to make sure the area was smooth for the rings to slip into.

Being interesting to see how Yamaha installs them on the production line.

George

George, I couldn't agree more with the way you went about that . For a job you are only ever likely do once or twice, special tools are not needed.

The method you describe is spot on. The key being taking your time, not forcing anything and "feeling" what's happening. Don't rush it.

You even used the same tools I do, a screwdriver and fingers. The only difference is I use a rubber mallet to tap the block, it delivers a sharper blow but without the force.

I have split ring compressors but like so many other special tools, by the time I find them and set them up, the job could be done several times over.

I believe production lines just use split compressors, either robotic or manual, depending on the scale of production.

Nice to see it coming back together.

Can't wait for the "running in procedure" discussion, it's been a while.

Excellent!

[yamaha fj rider]

George, good to read that you are getting it back together.

Kurt

[aviationfred]

Looks like the engine is coming along very well. I can't wait to here of the 'Seat of your pants' power increase.

Fred

[jscgdunn]

Hi George,
Great progress.  Last winter, as you know I had a bit of and issue with a shim that got away on me and gouged the head the bucket sits (bucket cylinder?). Any how Noel provided me this great write up for re-installing the head with some really good tips.  I am pretty sure you will not need it but I thought it was a good "how-to" to go along with your cylinder installation:

Hi Jeff,
Relieved to hear you have some hands on experience and are armed with manuals. Much as I like seeing people have a go, there are some who's brains are just not wired for it.


There's not much to putting a head back on that isn't either common sense or covered in the manual, but you are wise to have some respect and proceed with caution.

Sorry to disappoint here but there are no real pearls of wisdom to pass on that come to mind other than the usual good work habits, don't rush, don't force anything, make sure everything is clean etc.
The cams and cam caps are marked making it difficult to get them wrong.

In no particular order here are some things to consider.

Smear the cams journals with some lithium grease or buy a tube of assembly lube.

Don't freak out if you drop the chain into the crankcase, it's not going anywhere and it's easy to fish out. It just loops around the crankshaft..

When installing the cam chain tensioner, it will rotate the inlet cam slightly as it takes up the tension, leaving it incorrectly timed. You have to position the cams such that it anticipates that movement. Make sure you do a final check of the cam timing once everything is bolted up and you have rotated the motor a couple of revolutions by hand, ONLY in the direction of rotation.
My chain had stretched and I could only get it half a tooth either side of correct. Some time later I installed adjustable cam sprockets. Not to tweak the timing but just to get it back to standard.

I think this is covered in the manual but when installing the cam chain tensioner body to the block, position the plunger as per the manual instructions and leave the spring out. Once the body is tightened up, install the spring and cap. Be very careful installing the cap, you have to compress a fair bit of spring pressure to engage the threads of the cap. It is finely threaded and the tensioner is alloy. A situation just made for cross threading.(lol)
You would normally start a thread by hand to avoid that risk but in this case you can only do it with tools because of the amount you need to push against the spring. I use a socket, 3" extension and ratchet handle for good control and eye balled it, taking a very gentle approach to turning it until I know the threads have engaged.

Do not forget the dowels and the "O" ring for the oil galley on the RHS.

DO NOT use any power or air tools when re assembling engines, feel is a big part of knowing things are seated properly and not over tightened.

FJ's can be a bit prone to base gasket leaks, so good head tensioning is important. As the tension is affected by friction on the threads, this can alter the clamping force for a given torque value, depending on what they are lubricated with. There is no hard and fast rule but anecdotely, this seems fairly forgiving. I would suggest just making sure they're not completely dry.

More important than that is the difference between static and dynamic friction. Once you are turning the bolt with the tension wrench, don't stop until it reaches the desired torque. Do not give it another turn to make sure once it has stopped turning. The force required to overcome the static friction once it has stopped, and start the bolt turning again is far higher than the target torque value and although the wrench will click immediately, the resulting partial  turn will over tension it. Without getting too technical, bolts are tensioned (stretched) to somewhere around 80% of there max. A couple of final checks can see this exceeded by a risky margin.

Not wishing to dwell on that point but I would torque everything down then back the bolts off (not with the tension wrench) one at a time and re tension them.

I wouldn't worry too much about spinning the engine over to get oil up the top. It will get there as soon as it would on a normal start and if you have smeared the cam journals and lobes with assembly lube or lithium grease it will be fine.

There is a bleeder screw on the RHS of the head you can crack if you wish to satisfy yourself there is oil getting through (described in the manual I think) but it makes a mess of a nice clean engine.
I would just fire it right up.

Don't be alarmed by smoke around the engine on start up. There is nearly always oil on the exhausts or somewhere that gets very hot very quickly.

If you haven't already discovered this, the throttle cables are a gazillion times easier to reconnect before you mount the carbies.(if you two cables at the carbies)

Make sure the throttle is working properly before you start the engine. You would be amazed how many fresh motors I have seen started with an enormous rev or stuck on full throttle once started.

Sorry there are no major tips or tricks in there but it is a pretty straight forward job.
I seem to recall the Haynes manual suggest putting the chain tensioner on upside down but as it won't fit, that is obvious.
Best of luck, hope something in there is of help, feel free to contact me anytime or if any of the above is unclear.

If I have any light bulb moments about something I have forgotten or something that might be of help, I will be in touch.

Apologies if I have have covered things you already know. It's always a bit dicky talking to people whose mechanical knowledge is unknown to me.

Noel

[movenon]

Thanks Jeff.  All information is good !  Never enough !!!  No matter what or how many types of engines you have worked on EVERY engine has it's own "quarks" or a better way to do something that is usually only learned by experience (sometimes costly). That's one of the many assets of this forum.

Fred: It was just time to look into the low compression and intermittent oil burning on start up.  I will be happy with just a good running reliable machine. Not that it has been unreliable... Just little low on power and a hard to describe smoking problem.  I mean I am use to aircraft recips and know that all air cooled engines smoke to some degree especially when cold. So I am not unreasonable.

Kurt: Thanks ! Did you get the bushing I sent down ? Good on you for helping out on the local members FJ.  Love how this works out sometimes.

Noel:  I was actually surprised at how easy the cylinder went back on. The biggest piece of advice I have is just take it slow. The rings are pretty easy to compress in.  I do think polishing up the bevel at the bottom of each bore is worth a few min. of your time before the final cylinder cleaning.  As I installed it by myself I put it in low gear and took two bolts, wedged one between the top of the rear sprocket and chain into the sprocket valley and one on the bottom of the rear sprocket valley and chain. I had a little movement of the pistons from TDC but nothing to be alarmed about. Once the cylinder is settled on it stayed in place.

Lots of different views on run in procedures.  At present I am thinking about doing 2 or 3 heat cycles (balance the carbs) then head to the hills stay in the moderate power range with lots of on and off the throttle due to corners and grades.  Just enough to drive the rings into the walls.  After 500 miles or so do a plug read, check valves, adjust fuel air, re-balance, change filter and oil and possably do a compression reading just because.
Here is an interesting read on engine break in.  http://mototuneusa.com/break_in_secrets.htm

Arnie:  Mileage on the engine is as best I know 39,000 mi.  My previous compression was 120 PSI pretty much across the board so I assumed it was the rings, bore wear etc.  I didn't do a leak down because no matter what I was going to pull it apart anyhow.  To me it was just to even of a compression reading to be the valves (unless they are are all leaking exactly the same).  It wasn't out of time and the valves were adjusted in spec..  WAG it was or is in the rings or glazed cylinder walls.  I thought about glazed cylinders and tried a few tricks along with running the piss out of it for a good 500 plus miles but no change.

Once apart the cylinders and pistons measured still within spec. The walls did look glazed with hone marks still visible.  I tried to see if the second compression rings were perhaps install up side down but the marks were worn off and it is hard for me to see or feel the bevel.  All I know is they are installed correctly now.
Bought new 220 grit flat hone shoes and honed the bores out to as close a 45 degree pattern as my eye ball can see. The pistons were exceptionally clean below the oil control ring, no burnt oil, discoloration, carbon etc. on the skirts.  I just wiped them clean with some gasoline. On the piston tops I used a brass wire wheel on the bench grinder and they came out great with no scratch marks etc.. As in the picture.

As an example without getting into a lot of numbers, the factory compression ring end gap spec for the 1200 is new installed .008-.014 in. with a max limit .024 and my replacement compression rings end gaps are .010.  Not new but good enough.  All the replacement rings were on par.

Keep in mind I am not trying to do a full rebuild, just freshen up and repair as necessary.  I have rebuilt to many engines and have been down the financial rabbit hole many time before. This time I am sticking to my "plan". Or so I say...  

The head is on the bench and in not to bad of shape. I am replacing 1 exhaust valve because I can predict a problem on it in the future. What do you think ?

I will write more about that after its back together.  
George

[Arnie]

George said, "I am replacing 1 exhaust valve because I can predict a problem on it in the future. What do you think ? Smiley"

My first thought was, Why has he put a diamond shape punch mark on that valve face?
Then I read your question (above) *
So now, I think you are pretty good at prediction :-)

Cheers,
Arnie

* I read posts in time sequence from bottom up.  Pics can throw in a bit of a monkey wrench

[Mark Olson]

George ,

Smoke on start up is usually valve seals/guides ... Smoke under acceleration is rings.

Give the head a good once over for sure ..
When you did compression test did you remember to hold throttle open for max reading? If not that will give the low psi reading.

[movenon]

George ,

Smoke on start up is usually valve seals/guides ... Smoke under acceleration is rings.

Give the head a good once over for sure ..
When you did compression test did you remember to hold throttle open for max reading? If not that will give the low psi reading.

Hi Mark. Yes I did the compression check correct (two different times over the last 12 months).  The smoking was intermittent sometimes it would be exceptable and other times it would fill up the garage. I found some of the problem.  I hate to admit any fault but stuff happens.  Last year before the rally I changed out the valve stem seals with the head on the bike.  It can be done... I was in a hurry as the rally was in just 2 weeks. The smoking improved a lot.  Almost exceptable.

Fast forward the present.  When I pulled the valves out I found one cylinder with almost no seal left in it (stock Yamaha seal).. Ummm.  I guess I screwed up.  Then I though hell I did a seal count when I got the seals from RPM and I wasn't short any..  Then upon pressing on with the tear down I had one valve stem with 2 of the nice seals on it from Randy ..  Oops.    I guess I have to laugh about it..

The guides are within limits by my methods of checking them.  I did a light lap and inspection using some Prussian Blue and found 2 exhaust valves with some very light pitting and one exhaust valve with a deep pit in the face.  The light pitting cleaned up easy and I  replaced the one valve with the deep pit.

Did a clean up lap with some off the shelf lapping compound and did a final polish with some 400 grit lapping compound.  All the valve faces and seats look correct and measure good.  Next step is to install them with out valve stem seals and do a chamber leak check.  If OK then back apart and install the seals (all of them this time).  Stock valve spring heights measured out good as per the Yamaha Service Manual.  They appear to be good but am giving some thought to buying some after market springs.

Hopefully I will be bench adjusting the valves and have it back in service in 2 or 3 weeks.  Other mods and projects are paralleling the FJ work here. 

I have to say anyone doing head work my strong advice is to buy RPM's valve stem seals. There are FAR better than stock or any others that I have seen. Looks to me like you would have to have some really shitty clearances for these seals to leak.

Today I pulled the oil pan and cleaned it up. Removed some debris from the cylinder removal, (plastic bits from the cylinder studs) installed new gaskets etc.. Also installed an oil temp sender.  Not much done but spring has sprung around here and some yard work was needed.
George

[yamaha fj rider]

George great to read that it is going back together. Keep up the good work. Going for a like new 1990 we see. Hopping to see it in person next month.

Kurt

[simi_ed]

George, if you pulled the oil pick-up off be very careful that it is installed correctly. 

Ed

[Capn Ron]

George,

Nice job and nice writeup...I didn't know you were going to tear into the lump before the rally!  I reinstalled the cylinder in exactly the same way...turns out those chamfers do a nice job of compressing the rings if you just take your time.

I tore mine down at 20,000 miles and after looking closely at 24 separate measurements of the cylinders and the pistons, they appeared to have zero miles on them.     Just put a freshening hone on the cylinder walls, re-ringed the pistons and all was good.

Looking forward to catching up at the rally!

[movenon]

George, if you pulled the oil pick-up off be very careful that it is installed correctly. 

Ed

Thanks Ed ! Is that KTM wore out yet ?  Nice thing about digital camera's you can take some record shots as you go.  Not the best picture but it was just for record.  



Looks correct to me the screen "arrow" is pointing forward.  If you get the pick up on wrong the gasket will not line up correctly. That could get interesting. I am not sure even if the pan would go back on with the pick up on backwards.  The screen has 3 notch's to line it up and an arrow pointing forward. This is my first time digging a little deeper into an FJ engine so all help and pointers is appreciated.  
George

[movenon]

George,

Nice job and nice writeup...I didn't know you were going to tear into the lump before the rally!  I reinstalled the cylinder in exactly the same way...turns out those chamfers do a nice job of compressing the rings if you just take your time.

I tore mine down at 20,000 miles and after looking closely at 24 separate measurements of the cylinders and the pistons, they appeared to have zero miles on them.     Just put a freshening hone on the cylinder walls, re-ringed the pistons and all was good.

Looking forward to catching up at the rally!

This is just a "fluff" up.  Nothing compaired to what you did Ron.  I am just doing the best I can with what I have.  Like you I found out that standard rings were just fine. As you noted the chamfers make it easier to feed the rings into the bore.

The head wasn't to bad. Caught a few items before they became a significant problem. Work still in progress there.  Hope to meet up with you along the road this summer.  Stay well.
George