Remove the head, or not?

[psycoreefer]

Hey all, looking for some general advise, I received for Christmas between the whole family a complete gasket set as well as a new cam timing chain. The chain needs to be replaced, at the beginning of the summer my tensioner had about 1/32nd of an inch of travel, and the bike generally runs like crap, I've been through the carbs a billion times with no real results so hopefully proper timing will help things out.

My question is what else should I do considering I'll already have the top of the motor part way torn down. I considered removing the head and having the valves re-ground but I'm unemployed now so I no longer have the money for that. I am planning on adjusting my valve clearances while i'm in there but is there anything else I can do for little or no cost?

I've read about lapping the valves which seems like a DIY thing but I'm not sure whats involved or how much benefit I might see from it.

Also anyone willing to lend a guy the tool needed for breaking the old timing chain and installing the new one?

[prometheus578]

"Did Geordi run a level three diagnostic first?"

Sorry...
New Years Eve.
Rather than spend the evening with drunkards, I watched 10 hours of Star Trek instead... but my question still is a valid one.
Prior to the partial disembowelment... did you take a compression reading? And if so, what were the numbers?
If the compression readings were good, there'd be no reason to mess mit der valves... other than to adjust clearances if needed.

Lapping valves is a simple proceedure that can help them seat better and cure small losses of compression. Simple proceedure to lap valves, but a real time consumer if you don't have the tool to remove the valves in the first place.
About half way down the page... $32
http://www.mikesxs.net/mikesxs-tools...ategory_id=7.1
Also on the same page is the cam chain tool $42.

Or, contact Randy as he has a spring compressor tool for loan.
http://www.xs11.com/forum/showthread.php?t=20554

The cam chain tool is not for removing the old chain, but for afixing the new cam chain master link.
Uhm... you DID get a master link for the chain, yes?

Many ways to remove the old chain, from masking off the area and using a dremel grinder to hacksawing or just snipping it with a bolt cutter.
Many threads on replacing a cam chain... and too many different techniques to chose from... too many for me to go into detail.
If you need more instruction just ask.
(It's going on 5:00am on New years Day.. I'd rather get some sleep than sit here and type info that you may not need)

Cam chain tool, like I mentioned, is for "squashing" the the pins on the master link... rivetting it together, so to speak. Several different techniques also can be used without resorting to the official tool.
One method would be to take a large sledge hammer and place it next to the backside of the master link.
Using a drift pin and another hammer, "peen" the protruding ends of the master link to "Rivet" the link piece in place.(The sledge hammer is to provide a backing force ... stopping the chain from moving when you hit it with the other hammer. A two man operation, to be sure.

Ok, time for sleep, now.

[psycoreefer]

10 hours of star trek, I'll bet you were dreaming of clingons and transporter accidents all night.

I haven't torn into it yet so its not to late to do the compression check, however when I checked it last spring it was around 160 psi on each cylinder. The bike has 50k and thats why I figured it would be good to freshen up the valves.

I think I've got the timing chain replacement procedure down. I've bookmarked and printed a few threads with instructions and gotcha's so I feel ok with that, other then that silly tool for securing the master link, which I did order. Could you maybe give a little more detail on the "backyard" method cuz I'm not spending 45.00 on a tool I'll use maybe twice, especially with the situation I'm in now. Is it really as simply as whacking it with a hammer a few times?

[XSPastor]

generally runs like crap???

Unless the tensioner was completely out of travel to extend any further, I doubt that it will run any differently when you replace the chain. The 1/32nd of travel you mentioned - do you mean that it only had 1/32nd left to extend? The comp figures you quoted for a 50k engine are great so the valves are probably not leaking; at least not enough to make it run badly. That only leaves carbs or ignition if it's not running well. Defintely check the shims and adjust if needed but I wouldn't tear the head off. Your problem is most likely elsewhere.

[boyat68]

I don't suppose that you re-built bicycles as a lad as many of us did because we could not afford a new bike or even a used one, but bicycle chains had to be extend or shorten by removing a link or two using a cold chisel, anvil and a big hammer. When putting the two ends back together we used a master link that came in two parts the link with one side open and a closure clip that fit down on the open link with the two pins sticking through. the holes in the closure clip. The job was finished by placing the opposite master link plate down on the anvil and using a ball peen hammer, beating the extended pins down on the closure, clip creating a riveted head to hold the master link together. Since the timing chain on the motorcycle has to remain on the sprocket, some method has to be used to peen the pins of the master link down securing the closure clip (link). It has been suggested to use a large hammer to act as the anvil or bucking bar in riveting language to absorb the blows from the peening process. It has aso been suggested that one could use a flat end punch to peen the ends since you cannot get a direct blow from a ball peen hammer striking the pins. The tool is just a device to facilitate the riveting of the pins by one person. you can readily see that a second person is necessary to hold the bucking hammer, while you deliver the peen punch blow on the pins at an angle that must be precise. I, myself would use that method since I cannot see paying 40 bucks for a tool where a second person could be cheaper.

[Ivan]

Most of the stuff I have heard about the XS valve train is that it is fairly bullet proof, and the valves really don't wear that much. I have heard an adjustment is necessary about 1000 miles after a valve job, then they pretty much stay put.

FWIW, John on the forum has a valve shim library that can be used to trade shims. There is a sticky on this in the tech forums I think.

If your adjuster has only 1/32 adjustment left, I would suggest that your cam chain is worn, or stretched as some might say. The other possibility is that you have not used the correct procedure for setting the tension, which can be bad. The timing mark has to line up with the "C" and not TDC for cam adjustment. To check cam timing, the marks on the cam caps need to line up when the pointer is at TDC. Another item of note is that over tightening the lock nut on the tensioner will pull the set screw back out, and strip the threads. DAHIK. Since I am lazy, and have access to a machine shop, I turned the face of my tensioner down enough that I have an extra 1/4" of throw. Worked well for me, and I wanted to ride instead of changing a cam chain.

There are a few write ups about changing the cam chain without pulling the head. Also, I read somewhere that a bicycle shop is a great place for finding a chain breaker and riveter for a modest amount, since the cam chain and a bicycle have roughly the same size chain.

I am in total agreement that if you have good compression, your valves are not at fault. If you have been through the carbs and are sure everything there is correct, that leaves ignition problems, of which the XS11s have a few notorious ones. The wires to the pickups are known for going bad. Also the caps tend to loos connection with the plug wires over time, so cutting off a quarter inch or so and reinstalling the caps may help.

Another basic thing that gets overlooked much more than should is just putting in a fresh set of plugs. After running bad for a while, the plugs will foul. A new set is the best way. If you are in dire straits and can't obtain a new set, use a propane torch and burn them clean again. The tang needs to glow red and the black stuff needs burned off the insulator. That should make them run, and if all other problems are gone, they will clean themselves the rest of the way in short order.

Kind of a shotgun approach at diagnostics, but the symptom "still runs like crap" leaves things wide open. hehe.

[prometheus578]

I remembered it differently...

I just checked my spare chain and link in the garage...
I thought the master link's "leg" had a small depression in them, but no, they're just solid rods.
I think, when I did the last one, that I centered a sharp punch in the middle of the leg and whacked it with a hammer, effectively making a depression in the legs and flairing the edges over the master link.
I've got that Cam Chain Rivetter tool. It works nice for master links (cam chains and drive chains)with a "starter" depression in the legs but with the solid leg types... I've found it easier to just use a sharp punch and hammer.
You ordered the tool, so give it a try.
One thing I would recommend... Take a digital caliper and first measure the thickness of the master link legs. Then measure the tip after you've beaten on it for a while just to ensure that they are indeed, flaired enough to hold the link together. As long as the flair is a bit wider than the original thickness, you should be ok.

[planedick]

Riveting

I used a good vise grip pliers, (Real Visegrip, not wanna-be) and they had good deep serations on the jaws which I used to flatten and crease the head of the pin. I did buy the special tool, but before I got to the aforementioned part I had already destroyed the part needed for peening the pin. DUH

PS: The compression of 160 probably means lots of carbon in cylinder, causing preignition problems etc. New compression is listed at 142 PSI plus or minus 10%.

[psycoreefer]

Thanks for the advice guys, I guess I'll leave the head alone for now and see how things go. I'll still have the gasket if I decide I want to tear in to it later.

I'm sure I adjusted the cam chain properly, followed all the directions, then removed it and measured how much further it could come out, it was about 1/32nd of an inch so I know my chain is streached. Maybe its not making a difference in how the bike runs but in needs to be changed anyway.

xspastor and Ivan - I shouldn't say it generally runs like crap, it runs well enough to get me to work and back but has very little power under 3k. I've had to up the pilot jets to 50.0's and set the floats at 23.7mm just to get it rideable so that I don't have to rev it and slip the clutch to take off. I've been through the carbs, replaced the spark plugs, wires, caps. Fixed the vacuum advance wires. etc, etc. If you want more background you can check some of my older threads but I feel I've been through nearly everything. I know what your thinking, that I didn't get the idle and low speed passages clean but I tell you I've cleaned the damn things a dozen times and it idles smooth and steady, its got to be something other then the carbs.

[bikerphil]

I've had to up the pilot jets to 50.0's and set the floats at 23.7mm

If you have the correct carbs for a '79 Special (BS34-II), then these float settings seem to be off from the recommended 25.7mm. Also, 50.0 pilot jets are HUGE. Shouldn't need anything larger than 45.0 (1 size up from stock)

[Ivan]

I have been fighting a dead band below 3k rpm.

It has been a steady progress.

Bigger pilot jets
advanced the timing ever so slightly
stretched out the slide springs in the carbs

Everything has helped. I wish I could get a gas analyzer and a dyno on it to see what is really going on, but those sort of things aren't cheap around here.

Dan Hodges suggested that a dyno jet kit may be the way to go, and I think that will be my next step, once i free up some funds.

Mine doesn't run badly below 3k at all, but it still feels like the afterburner kicks in at 3k.

[psycoreefer]

phil, that was kind of my point, with stock or +1 sized idle jets and floats at the proper height the bike is unrideable. It idles fine and is fine from around 3K up but when taking off it will stall, stumble, backfire and have no power. With stock setup the only way to ride it is to rev to around 5k and slip the clutch when taking off from a stop. If you interested in helping me try to diagnose I can tell you everything I've done.

Compression test, Ignition test, new plugs, new wires, new end caps, cleaned carbs ten or more times, rebuilt carbs with all new parts. Replaced idle and main jets with genuine Mikuni jets. Replaced emulsion tubes with new OEM tubes. Replaced metal floats with new plastic floats. Balanced carbs. Adjusted idle screws with the "ear" method as detailed around here. Fixed broken vacuum advance wires, Checked timing with timing light, replaced the battery.

All of these and probably some more that I didn't remember right now check out fine, no problems and yet I have no low end power unless I jet way rich, and it should be noted that even with the floats set as high as I have them and the 50 pilots the plugs read light grey, not overly rich like you'd expect.

At this point I'm down to only two things that I can think of, something strange with the valve/cam/timing, possibly some sort of after market cams or maybe the valve timing is off some how, which I'll be able to verify when I tear down for the cam chain replacement. Or bad coils although my spark looks good I've read reports of weak coils causing problems that defy logic.

I'd love to have the bike running at its full potential but at this point I've kind of accepted the fact that I'll always have to have it jetted funny with mediocre performance unless I stumble on a "duh" while working on something else.

[bikerphil]

Replaced metal floats with new plastic floats.

Ok, that explains the difference in float level. Popping signifies lean mixture for sure. Have you replaced the gaskets between the head and carb boots? In one instance on an XJ that I was tuning, I had to set the floats 3.5mm richer from the stock setting to get it to run right. It had the same symptoms that you are describing. This was with the later carbs though. I still don't have a logical explanation for having to set the floats that way, but the bike runs pis ser now. Don't be afraid also to richen it up by moving the floats some more and running the mixture screws out some, whatever it takes. If you get it adjusted too rich, you can always bring it back to a happy medium. Mixture screw tips aren't broken off, are they? I'm sure you've checked that already.

[trbig]

Have you actually watched the vacuum advance working? Almost sounds like it's plugged and not advancing at low RPM.

As far as the cam chain, my replacement chain had hollow legs on the master link. Something heavy behind it and a sharp center punch peened the ends open. Prometheus mentions a chain that doesn't have the hollow legs.. so I guess what method you use depends on the type you get.

Don't forget to feed the new chain down and around the crank while attached to the old chain. If you happen to drop the chain into the motor, one of those telescoping magnets attached to the tip of a long screwdriver to help guide it down (And keep from grabbing onto other things) will get the chain back up to the top.

Tod

[prometheus578]

"We are the hollow men..."

Shape without form, shade without colour...

Prometheus mentions a chain that doesn't have the hollow legs..

Yeah, that sort of threw me, TRBIG.
I recall using the hollow-legged type, but the one I found downstairs was solid.