Screwed up big time...XJ head

[skids]

I am sure that Jerry knows what you meant and maybe 90% of the other readers. So I suppose 10% are out there RIGHT NOW bending valve stems!

[Jerry]

Pulled the cam chain cover, can't see any problems from the top. Cam chain adjuster did have a small bit of travel left, was not all the way to the end. (I pulled it as well to check to make sure the rubber cap was still in place, released the stop bolt and plunger moved forward a bit until it hit the end of its travel.)

Grabbed my manual, it also mentioned the dots on the cams, but I must be dense...where are they located? Sounds like they should be near the center caps, but I couldn't see a dot on either cam. Was looking from the engine's left side, which side of the caps are the dots on?

Have decided to rebuild the head if only damage is to valves. While not the cheapest option, I might as well do the job right.

Interestingly, the XJ manual recommends not splitting the timing chain for head / cam removal. Since I will be replacing the chain anyway this is not an option, but I was under the impression the chain had to be split for any head work.

Will check back threads, but will need a chain breaking / master link installing tool. I know a couple people have made recommendations in the past, care to make them again? Also, is there a consensus on what brand of replacement chain is best?

[dbeardslee]

Jerry - stand on the left side of the bike and look towards the middle of the cams. You will see little arrows on the center camshaft caps that point towards the left side of the bike. This arrow should line up with the dot which is on the raised portion of the camshaft right next to it. If you have a Haynes manual it's shown on page 81.

On rebuilding the head - Mikes XS has a very nice chain breaking tool on their tool page . Mikes XS part #35-0112. It is identical to the Motion Pro tool, but costs half as much - $39. You can pickup the gasket set at Partsnmore for $77. The gasket set includes the valve stem seals, valve cover gasket, and the head gasket, chain tensioner gasket, as well as a bunch of other gaskets. Bikebandit wants like $105 just for the head gasket, so this kit is a real bargain. Identical to the kit Z1 sells for over $100. If your cam chain is getting pretty stretchified, partsnmore has one for $32. I would recommend getting some extra links with it also. Mikes XS has a set of lapping sticks for $4.50, but you only need the small one.

I just did this job several weeks ago and can testify that it's pretty easy and makes a huge difference in the way it runs. Be careful when reinstalling the camchain, and don't crimp the link until you are sure you are right on the dots. It's very easy to get it one tooth off.

Should have mentioned this above, but I'm assuming you have stock cams. If you have aftermarket cams you may not find any dots and may have to use a degree wheel.

[saddle up]

Originally posted by dbeardslee
Saddleup - stop me if I'm wrong, but don't the cam dots line up on the "T" mark, not the "C" mark.

Sorry guys, I didn't mean to give out bum scoop. you got me. An honest mistake

[Ken Talbot]

Saddle Up - I've inserted beardslee's note, and your response, into your earlier reply.

[trbig]

Jerry,

Nope, you don't have to split the chain. When you get the cam caps off, you can slide the cams out from under the chain. Make sure you tie the chain up to the frame with some string or it will drop down into the chain galley and into the bottom of the motor.

Since you will be cutting the chain to replace it anyway, this isn't important except for future knowledge. Put a rag down over your head best you can and a Dremmel cutter or regular cutting wheel will do the job on the chain. For the new chain, when you install the master link, the last pin you slide in will need the ends peened out a bit with a center punch. You'll need something behind it to hit against. That's the easiest and cheapest way anyway.

There's a colar on the cams that has a dot on it... I labeled with the white arrow. The red arrow is the arrow on the caps it needs to line up with.






This has got to be frustrating and a litle scary if you think you did everything right, and still bent valves. Just take it slow and think about each move before you do it. Let me know if you need any of those valves.


Tod

[Jerry]

OK, I pulled the valve cover and found the "T" mark and cam dots not anywhere close to each other. Also found the 2 cams were off by 1 cam gear tooth; to make both dots line up I had to rotate the intake cam back 1 tooth.

reset the cam dots to the "T" mark, still no compression, so I pulled the head. Looks like all 4 intake valves had hit pistons from the marks on the valves:



This brings me to 3 questions: First, there were no shims at all, either cam, between the cam lobes and valve lifters. is this possible?

Second, what is the best way to remove the lifters?

Third, what is the best, or at least a good, valve compressor to use to remove the valves? I am a novice at this, so any recommendations would be welcome.

I have a new cam chain, link, gasket set, and cam chain splitter/riveter tool on order from Parts & More. Gasket set includes new valve seals.

Trbig, will send you a PM on the valves. Looks like I will need a set!

[dbeardslee]

Jerry - You can make a valve spring compressor with a piece of pvc tubing and a 6" C-clamp. Just cut a little window out at the bottom of the pvc maybe 1/2" wide by 3/4" tall to allow access to the stem locks. Wrap the end with a rag to prevent damage to the head and place that end directly on the face of the valve. Put the PVC tool on the lifter with the screw end of the c-clamp on top of it. Turn the handle on the c-clamp and it will compress the spring. Stick a magnet through the window and you can fish out the stem locks. Here's a pic:



When I did mine I had some issues getting some of the buckets back in. There was some scoring in the lifter wells that prevented them from going back in. I took a brake cylinder hone attached to a drill and ran it up and down several times in the offending holes and they dropped right in.

Sorry about your valves. What a buzz-kill!

[Jerry]

Some progress...

I have the old valves out thanks to dbeardslee's tip, plus a set of replacment valves donated from trbig. Old valves are bent:

Replacment valves have been lapped in, old valve seals pulled, new cam chain installed. Gasket set has arrived so tonight I will replace the valve seals, reassemble the head, and hopefully get the XJ put back together tomorrow.

An addendum to dbeardslee's tip: I bought a 2nd end end cap for the pvc pipe, cut a slot in it and put it on the bottom side of the C-clamp. End cap has a dome on it that fits nicely into the recess of the valves and avoids metal-to-metal contact between the clamp and either the valves or the head. On the top side of the clamp I had to cut the dome off so the other part of the clamp - the moveable foot - would have a flat surface to press on.

I pacticed reinstalling a valve; did not have that much problem as I coated the backside of the keepers with grease to hold them in place while I released the spring. A pair of long tweezers helped place the keepers next to the valve stems.

[audijunky]

How this may have happened??? The only thing I can think of is when you pulled your tensioner to put on the new gasket, the chain got some slack down around the crank, and when you released the tensioner upon reinstall the chain skipped a tooth at the crank. Sounds pretty logical to me. In the Haynes manual it tells us to recheck the marks on the cams when the tensioner has been installed and tensioned.

Now Valve buckets with NO shims??? Thats a new one. How long you had the bike?

[dbeardslee]

Jerry - Sounds like you are making good progress on the head. Gotta give credit to BikerPhil here, as he's the one that showed me how to make the valve spring removal tool. Glad it worked for you.

When I did mine I got a big rubbermade square-bucket/storage container thing at Walmart. I put five gallons of diesel fuel in it and gave the hole head a good soak and scrub. It also came in handy after I lapped the valves to wash all the valve lapping compound out of the head 'cause if any of that stuff gets left in there it can cause problems. Also, I left the old valve stem seals in while I was lapping and didn't replace them 'till I was ready for reassembly. Wasn't sure what the diesel would do to the seals. To keep everything organized I got eight containers and numbered them 1-4 I (intakes) and 1-4 E (exhausts) and put the corresponding parts in. Made sure I had containers with tops as everytime I do something like that I wind up kicking the containers somewhere during the process. I probably shouldn't leave them on the floor.

When replacing the cam chain (if you broke the chain) you can take the rivetable link, put it in place but DON'T rivet it. Hold it together with the fingers of your left hand while you move the cam chain back and forth with your right. That is to say turn the timing plate COUNTERCLOCKWISE until you are pretty well past the marks on the cams. Then turn it CLOCKWISE until you are on the 'T' mark on the timing plate. Check the dots. With a new chain they should pretty much line up dead-on the arrows. One tooth only moves them a small fraction of an inch off the marks. If they don't line-up perfectly take the rivetable link out, move the cams however they need to be moved and do it again. Don't rivet it until they line up perfect. Also, don't remove your safety wires until the chain is installed correctly and riveted. Make sure you have rags covering the as much of the cam chain tunnel as possible, 'cause if the side of the rivetable link gets away from you it's probably going to head straight for the tunnel.

Once I had mine back together where I was pretty sure it was right, I cranked it around by hand several times carefully listening for metal-on-metal contact, and watching to make sure the marks kept aligning correctly. Then I put the valve cover back on, mounted the carbs, and test fired her. It was only after I reset the timing and heard her running sweetly that I was able to unclench my butt cheeks

[Jerry]

Success!

OK. I put the head back together and put it back on the bike. Took particular care to make sure the dots on the cams were lined up correctly! After I was sure the "T" mark / cam dots were OK, I turned the engine over by hand several revolutions, then lined up the "C" mark and reinstalled the cam chain adjuster. For the first time ever I heard it click when I releases the stop bolt. Turned the engine by hand a few more times to make sure cam alignment was good.

Put the bike back together, crossed my fingers, and fired it up. Success! It is running well on all 4, and the engine is mechanically quieter now than it has been since I bought it. Valve clearances - checked cold - were in spec. I put a few miles on it yesterday, will double-check nuts / bolts tonight and try cleaning it up a bit. I am really glad to have it running again!

My thanks once more for all the help and advice from everyone who contributed to this thread, particularly Trbig and dbeardslee.

[saddle up]

On the road again,,,

I am so happy that you got her back on the road. I'll bet you are shaking like a 16 year old. Nothing like doing your own wrenching. The satisfaction is almost as good as sex . lol

[dbeardslee]

Saddleup - Maybe it's just me, but if turning wrenches reminds you of sex you're doing something wrong on one or the other

Glad you got it running, Jerry.

[CarolynS]

Hauntingly familiar...

This all looks so spooky.
I'm glad I'm not the only one who had the 'Horror of the Valves'. It's like the 'Silence of the Lambs' but much scarier!
Ed said something like what happened to your bike, happened to mine. Amazing how much damage can be done with such a small thing.
I'm glad it all worked out for you and you're up and running again.

dbeardslee-from a woman's point of view turning wrenches CAN be more satisfying than sex, depending on the wrench!!LOL!
Hope that didn't get me in trouble...