idle chatter (pun intended0

[grshantz]

I've had this chatter at idle for a while. . . lately it seems worse. I tried minor checks and adjustments with no successs. I am now going though the bike step by step. plugs 1, 2, and 4 are a nice tan. #3 is black. A compression test shows 150 to 155 in all cylinders. BTW it is a 1981 XS1100H with no modifications. Today I was checking the valve clearence and found most of the clearences under minimum. The intake was .102, .102, .089, .089
The exhaust was .216, .216, .203, .152. I checked the clearence of each valve manny times to make sure of an accurate reading. I would think that after 23,000 miles the clearence would have opened up. I also tried the motion pro tool from dennis kirk to check the pads, but the tip wouldn't reach the top of the valve.
At the same time I am going thought the bikes electrical system and cleaning all the contacts to eliminate an electrical cause to the problem. I adjusted the cam chain tensioner this spring.

These are my questions;

are the valve clearences a concern.

I remember reading that someone had to modify their motion pro valve tool to make it work. Can someone remember what that fix is.

Where do I get new valve shim pads?

What is the best way to clean corrosion from electrical contacts.
Is there a spray cleaner? or do I have to replace the connectors.

I know it's a lot of questions, I have been working on the bike for a couple of days and have not been able to figure out the problem.

Thanks,
Glenn

[xssiveone]

Not sure about the chatter at idle. Maybe be a bit more specific as to what area the chatter is coming from. Might be as simple as doing a carb clean and resync. Syncronizing the carbs is adjusting all carbs so that they are all drawing equally. This makes sure that all cylinders are doing their job and one isn't pulling harder than the next one.

>are the valve clearences a concern.

Yes, and they should be adjusted within recommended spec. The valve clearances seldom, if ever, "open up". They always seem to close up as the valve seats itself furthter into the head.

>I remember reading that someone had to modify their motion pro valve tool to make it work. Can someone remember what that fix is.

Yes. That was me. In order to get my MP tool to work, I ground some material off the surface that sits on the valve cover mating surface, allowing the tool to sit lower and contact the valve bucket. I also had to elongate one bolt hole for (I think) #3 exhaust.

>Where do I get new valve shim pads?

At the dealer or m/c wrecking yard. Most dealers will have a stock of used ones that they will sell you for cheap, or even swap for the ones you take out.

>What is the best way to clean corrosion from electrical contacts.
Is there a spray cleaner? or do I have to replace the connectors

Wire brush, jeweler's file, spray contact cleaner, elbow grease. No easy, clearcut way to do this. Find one you like and do it that way, but be prepared to commit time to get it done. Also, once you get them clean, apply some dielectric grease before you plug them back together. The dielectric grease will help ensure you, or the next owner, will not have to do this again.

>I know it's a lot of questions, I have been working on the bike for a couple of days and have not been able to figure out the problem.

No it's not... you will have more, trust me!! Buy/steal/borrow a manual if you don't already have one. Ebay is a good source for used ones (and sometimes new ones) and there is also a member that sells the manuals and parts fiche on CD for next to nothing. Contact Rob Mills at rockjok@imt.net for this.

And, finally, be sure to check the Tech Tips for information on repairs and modifications for your m/c.

[Ken Talbot]

So many questions...

• adjust the cam chain tensioner again, it is a quick and easy thing to do even if that's not the source of the chatter
• while you've got the cover off, check for rattling in the operation of the vacuum advance plate
  
  Here's a few places to look for valve and shim info in the tech sections...
• check out thread 824 and thread 818 in the XS/XJ discussion section for lots of info on clearances, motionpro tool, etc, etc
• spray cleaner will help with dirty contacts, but you may need to remove the metal parts from the plastic housings to get at them properly
• new terminal parts are available, check out thread 352 in the links section
• also check out thread 459 in the repairs/battery and electrical section for an article on restoring corroded electrical connectors

[strom]

It can be the camchain... maybe the clutch. This was pretty bad on my GPz... and it's easy to check... if it chatters while in 1st and standing still, it's not the clutch. Check for keyrings and tags bouncing off stuff (while test riding a friends guzzi there was a constant ringing sound... till I noticed a metal keyring dancing around the lock and ringing).
It may also be a carb out of sync...

Another solution is to get an older ducati... LOL... everything chatters, rattles and produces funny noises there.

LP

[grshantz]

Thanks for the great advice! the referrence to the past threads also helped. After reading all the replys, I am thinking the noise may be a valve not completely closing. The sound is like a low chirpping. That is low in pitch not low in volume. I used my long handled screwdriver to listen at different points in the engine and did not hear anything abnormal. It seemed the loudest when I listened between the airbox and the transmission without the screwdriver. The bike is in neutral and at idle when this happens.
When I bought the bike last August, it had stock carbs from a 79F. It made the sound then. Because the plugs were black most of the time, I picked up a set of newly rebuilt carbs from an 80G. I presynced them before I put them on and test drove the bike. The sound is still there. But the plugs look much better except for #3 which is still black. (That is another problem).

As far as the electrical, I have been procrastinating on this for a long time. Whether it contributes to the problem or not, it still needs to be done. I went to radio shanck and picked up a set of 4 tiny files for about $5 and a can of spray contact cleaner with a brush on the end. The cleaner claims it will remove oxidation as well. Yes I will test it on a sample piece of plastic first. I am also going to try and use my dremel tool with the wire brush at a slow speed. I'll let you know how this works.

In the mean time I will have to either find a good valve shim tool or modify mine.

Thanks again,
Glenn

[Zen Dragon]

my 79sf chattered when idle for a while when i first got her.

I adjusted the camchain tension

thant was the end of my chatter.


Just my 2 cents worth

[grshantz]

The idle chatter is gone. I went through and followed many of the tips to try and eliminate those possibilities. I also adjusted the valve clearances and the cam chain tensioner. My local bike shop mechanic loaned me his Yamaha shim tool and allowed me to swap out any shims that I needed(BIG HELP). Plugs #1, 2, and 4 were a light tan color and #3 was carboned up. so I swapped plugs 3 and 4 to see if it was the plug. I also trimmed
back the #3 plug wire as recommended in the tips. All 4 are firing very nicely now. I know they say to keep your hands off the idle mixture screws. However, these carbs passed through a few hands before they came to me. So I had to check. They were 1.5 to 2 turns out. The book says they should be 1.25 turns out. Is this correct for an 81H?

When I started this process I drained all the gas from my tank so I could start with fresh fuel. After all my adjustments, I put in one gallon of gas to test drive it. As it leaned on the side stand, the bike began to chatter and stutter. Yeah you guessed it. The right side was starving for fuel. This chatter was very similar to the original problem. So I'm thinking that the original problem may have been a fuel related problem.

Since my bike is running better than it ever did, I just can't seem to stay off of it. Yesterday I went out for a late afternoon ride around all the curvy roads I could find. On the way home I stopped off at a freinds house to catch up a little bit. I'm not paying attention to the daylight and soon start to see headlights. Then I remember . . I have no headlight. I took the faring off so it would be easier to work on. That was one scarry ride home. The sun had just gone down. It was still light out but dimming fast. I had to hand signal all my turns since I had no turn signals either. I have never felt so vulnerable on a bike before. The cars on the side streets would start to pull out and then stop when they saw me. I could just read their minds. I can't believe this idiot is out driving without a headlight. Neither could I. Yes I made it home safe. No I won't do that again.

Thanks for all your help,

Glenn
81H brown
81H blue