Finally got over my fear...

I finally opened up my cylinder head to check my valve clearances. Exhause was:
1- 006. 2 .006 3 .006 4 .005

Intake was a little more inconsistent:
1 .003 2 .005 3 .004 4 .003

I noticed a lot more oil in my head than in the pictures, is this normal? Also should I worry about pitting? I noticed the exhaust lobe on the far right cylinder had some rust and pitting.

 

That's in inches right? If so then three of four exhaust are as tight as they can be and .005 is too tight, .003 too tight on intake and .004 probably is too. It's better to use a metric only gauge to check them, you probably need to increase clearance on 7 out of 8, with the .05 intake ok, but hard to be sure w/o metric.

Fitz cleaned up the latent oil in his pictorial to improve the details that could be seen. So no worries there will be plenty of oil sitting there. Pitting is not good but it's not the end of the world either, can you get a picture and post it? Is the pitting on the lobe end or the short side? Probably means the bike sat quite a bit on the side stand and it was a humid environment.

Don't run that mill until you get those in spec.

 

Yea, I guess the side stand would explain the pitting. I'll try to get a pic after work. I've got a lot to do to get this bike road worthy. I just finally got it to start again after a 4 year sit in the yard. Out of curiosity, what are the consequences of running that tight?

 

Also, mine is a 650j, so the clearances for intake and exhaust should be the same, right?

 

Consequences: Your valves don't close properly when the bike is warm. The result is poor heat conduction between the valves and the head (causing warping), and if the valve seat is damaged and/or not sealing completely, the valve "burns" as the hot exhaust gases escaped during combustion.

This all results in poor compression and poor running. If you feared this task...you won't want to burn a valve. It's fixed by doing a true "valve job" where you pull the head and have to machine/lap the valve faces. It's MUCH easier/cheaper to pull the valve cover and change shims to keep them in spec on their maintenance schedule.

 

Yikes. Sounds intense. Thanks. After opening it up and getting in there, it's not so bad. A few weeks ago, I was ready to push this thing in the river, now I'm feeling a lot better about it.

 

Yeah, when I first adjusted my valves, I felt like I was "diving INTO the engine." You see cam lobes exposed, timing chain...and you think, "I shouldn't be in here." But feeling relieved and confident once you get in there is a good sign.

Carbs, brakes, and forks are VERY similar. They'll seem scary because you've never seen the inside of those assemblies, and no matter how many pics/diagrams you see, you just can't put it together in your head until you're in there. But these really are some simple components and you can do this stuff yourself.

 

Hmm...should have asked you for your bikes info first. Can you put your bike in your signature line so we know what it is. But to be clear your saying you have a UK spec or an XJ650J? If so then yes I think your right and your clearances would be:

EDIT-THESE SPECS ARE WRONG IT's BEEN PUBLISHED AND REPRINTED BUT IS WRONG
Inlet 0.16-0.20 (0.006-0.008in)
Exhaust 0.16-0.20 (0.006-0.008in)

So since the above is wrong my advice below is wrong, sorry please ignore this next section
So you would for sure be too tight on all but the .006's, and again that's why I would say measure in metric because you can't be certain those .006 ones aren't over the limit. Because .16 millimeters = 0.0063 inches.

The rest is fine
ManBot13 is telling you straight both on consequences, this is exactly how valves get burnt because they don't seat fully and disperse their heat into the head, and on doing it yourself. It's not that bad but you will need to resynch your carbs once you get them in spec. So don't push it into the river. It will run better than ever once you get it done.

 

NO NO NO NO NO.

The "intake 0.16~0.20mm" spec is WRONG no matter what "spec" 650 you have.

That was a mistake (a typo) in one of the factory service "guides" that has been picked up and propogated by the Haynes manuals.

AIRCOOLED XJ 550/650/750s; Euro or otherwise:

Intake: 0.11~0.15mm
Exhaust 0.16~0.20mm

 

well, i just ordered the hold down tool today, so i figure id rather wait until that gets here, so i can actually see what shims i need before i open it up again.

Well, the bike just cant sit there doing nothing. So, i decided to take the forks apart so i can figure out what i need to replace, and i got to the damper rod, and realized the retainer bolts are completely rounded!

i guess nothing comes easy on a 200 dollar 30 year old bike...

 

No, it certainly doesn't.

Welcome to the club.

We have T-shirts, jackets AND coffee mugs.

It matters not if you spent $200 or $1000; you're GOING to sink around $600~$800 into it if you expect to actually ride the bike.

And that's for parts; no cosmetics and you do all the work.

I got my first XJ on the road in about 5 months, and was plagued by "problems" for the next season and a half until I saw the error of my ways.

The '83 took about 10~11 months; but it was worth it. NOTHING overlooked or left out. It's been like a new bike since it went back on the road, almost 10K miles ago.

 

Yeah, I'm not gonna go that far. Its more of a rat bike. I just want it to be safe and run great.(which apparently they can).

 

What Fitz was telling you is the minimum necessary to make the bike safe, and ridable. Otherwise you will continually be haunted by problems.

Once you have taken all the steps necessary to recommission the bike it can, and will be a very reliable bike with just normal maitenance.

Ghost

 

I'll second that bare minimum thing. I am a very "do the minimum" type guy, especially on mechanical stuff. But even *I* put new tires on and replaced those rear brake pads right off the bat. Here is the order I would do it in, if I got another old bike:
(this is a case of "do as I say, not as I do" since I was painting the tank when the bike still had ancient tires on it)

1. put new brake pads in that rear drum, you don't want delam(I never heard of it before it happened to me, and it did happen to me years ago, pre-XJ)

2. check the date codes on those tires, replace if over a few years old.

3. rebuild the whole front brake system(I did just the M.C. and rears when I got bike, now I got dragging front caliper), so do the caliper rebuild and master cylinder, that part is easy, and lines for sure, those also have date codes.

4. put an in-line fuel filter in that thing, you don't know what's going in your carbs.

5. adjust valves, so you're on the right track there. (I put it off because I was convinced they were adjusted right before I got the bike, I just did them again and they weren't far off, but out is out and in is in...so I'm glad I did it now and not later)

6. replace those stupid glass fuses, I was proud of my beautiful OEM fuse box and how good it looked, until I snapped off one of those metal clips that hold the fuses, then it was off to the junkyard for an ugly, but modern, blade style fuse box.

7. Replace the control cables, especially clutch.

8. Change the oil/filter/plugs/air filter(this step can be done anywhere, this order is just my preference and as I think of them)

9. Clean up wiring connectors, especially in headlight box.

10. Fork rebuild if necessary. Also wheel bearings, steering head bearing. Again, if necessary, easy to test.

Most of that doesn't cost much, is the good thing. Then after that basic stuff I would worry about tuning it just right, rebuilding and syncing carbs and so forth. I haven't done anything to my carbs as I like how my bike runs, but it's on the list, just a little further down than most people would put it. My bike didn't sit either. Any bike that sat a long time, you'll for sure have to "de-varnish" those carbs.

Very last(and here's where I am all bass-ackwards) is cosmetic stuff, paint, polish, detailing. Also mods. I'm sure I left out somebody's favorite mandatory rebuild item. But this is just a general outline from a lazy mechanic to give you an idea of the ABSOLUTE minimum number of things you're looking at. I live where there's no inspection whatsoever for bikes, so I could get away with anything...until I get killed.

 

Yeah, that's pretty much the list I have. I've already done the fuse box and turn signal relay, starter solenoid and cleaned the contacts. Front tire was brand new 2 years ago, and has never seen the road. Forks are off the bike right now, and the valve tool is on its way.
Carbs will probably wait until the fall. It fires right up on the first push. I got lucky at a scrap yard and found a set with pristine innards.

Not going far was in reference to cosmetics...

 

The time and investment I was referring to DOESN'T INCLUDE cosmetics. I was simply talking about making it safe and reliable.

Here's the thing: the bike will force you to do anything you skip over; it will crop up as a "problem" soon after you start riding it. The more thorough you are to begin with, the easier the overall process becomes. And the fewer "problems" you'll have going forward.

 

Got my valve tool in the mail today! Couldn't be easier. I'm starting to feel pretty good about this bike. I only need one shim and I found a place in town that sells em for a couple bucks

 

<a href="http://s1243.photobucket.com/albums/gg553/aaronagosto/?action=view&current=cb066e77.jpg" target="_blank"><img src="http://i1243.photobucket.com/albums/gg553/aaronagosto/cb066e77.jpg" border="0" alt="Photobucket Pictures, Images and Photos" /></a>

Here is the rusty cam lobe

 

pic didn't insert right.

 

reposted



looks like it's on the short side (no contact)

 

Cool. Looking at it closer, it seems to be more surface rust than Pitting also

 

So I was in there today, messing with my shims, and I noticed a slight gas smell. Should this be cause for concern?

 

This includes the turbo too!! I wasn't aware there was a mistake in the published figures but thankfully in the Turbo service manual, they have listed it correctly!

jeff