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I'm struggling with a noise that is eminating from my 2003 1800C engine while it's at idle. The best I can describe it is that it's a "clunk" but there are some weird aspects to the whole thing;
- It is significant enough that I can feel it in the handlebars when it's clunking
- It appears to happen only at idle but stops at any RPMs more than approximately 1000 rpm
- It's inconsistent. Sometimes I run the bike for days with no sign of the problem and then it comes back again.
When it does, it's unmistakable.
- Engaging/disengaging the clutch does not affect it
- It's not rhythmic like a valve ticking

I have ~17,000 miles on the bike and I've maintained it by the book all along. I'm running Amsoil in it (since ~12,000 miles).

This is weird enough that I'm not sure what to think, but even though it seems to stop at riding speed I'm afraid to ride for fear that it may be damaging my engine. Does anybody out there have any guidance on this one?
 

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Sounds like a miss. They come and go, unpredictable, you will feel it. Tighten the battery cables. Do the ground fix as seen on the "How To" board
 

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Discussion Starter #3
Interesting theory I hadn't thought of. Thanks.
I did the "ground fix" you're referring to several years ago but I'll recheck my ground and battery connections.

My problem has the feel of something mechanical but this is why I asked.
 

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Sometimes I think I hear weird things while stopped at lights just to get to the next light and find out it was the car next to me or in front. Stuff makes noises, being on a bike we hear it more. Most of the time it is nothing.
 

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Discussion Starter #5
This isn't something I'm experiencing out on the streets. The bike is in the confines of my own garage. I know what you're saying, but this clunk is fairly dramatic (certainly not subtle). When I showed a friend and he was taken by surprise by it even after I had described it to him.
 

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What's your idle RPM? The decompression system kicks in when the idle is too low.
 

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Could be a little piston slap?
These engines have a large bore, long stroke and short piston. All can be contributing factors to piston slap at very low RPMs.
I have noticed mine making more noise that I like at slow idle, I run the idle up a little on the fast side, probably have better oil pressure too.
Some guys like to run the idle low so the bike lopes when putting around parking lots etc. Not a good idea. We haven't seen many of these engines torn down and don't know if piston slap is common. I have seen some pictures with scuffing on the cylinder walls and a little piston galling. If anyone else has noticed this problem, I would like to see the pictures.:dontknow: sb
 

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The noise that mixnutts is describing just doesn't match piston slap well. Piston slap is normally the loudest with a cold engine. It is rhythmic at the same rate as a valve tick. Engaging the clutch should cause piston slap to get louder.

The click going away with RPM increase doesn't match the symptoms for a loose connecting rod or piston pin.

?????????????
 

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I'm with Bubba... check the idle speed. If the decompression system is kicking in it will make some wierd noises and it won't be consistant. It will only do it when the idle drops low enough to activate the decompresion system.
 

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Discussion Starter #10
You guys are awesome and I really appreciate your help. I haven't had a chance to recheck my electrical ground fix but I can tell you my idle is at the higher side. I don't have an exact number (no tach) but it's not slow.

I'm feeling a little silly trying to explain a strange sound but I'm going to try again. I just ran it for a few minutes and it's sort of a "da dunk, da da dunk, dunk, dunk, da dunk, da dunk, da da dunk, dunk, dunk, ..." . It's definitely not rhythmic like a valve tick and it's something you feel as much as hear.

My local dealer's service tech was good enough to talk with me for a few minutes. I haven't taken it down there yet because I'd rather be able to send my daughter to college some day. He told me it might be my cam chain tensioner. Have any of yous guys got any experience with the cam chain tensioner? What does it sound/feel like when it begins to fail?
 

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Sorry mate, i'm no help with the cam chain tensioner. Just wondering if it may be missing. If one cylinder isn't firing sometimes it would make a 'da dunk' sort of noise.

Have you posted on Bare's website. He's the tech guru on these bikes.

Cheers,
Brian
 

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Have you changed the spark plugs? Don't bother with the Iridium. They foul just as fast as anything else and Honda is super proud of them. Try BKR5EIX-11. You should be able to get them at the Honda shop or a parts store.
 

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I agree with others that it sounds like a miss. pull your plugs and look at them. that would be the first thing I would do. If any look bad, you might try to clean them, I used a wire brush on mine w/ no ill effects so far (my bike was missing, popping, and backfiring BAD), but some have said that a wire brush wears the iridium or something off the plugs.
 

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I agree with others that it sounds like a miss. pull your plugs and look at them. that would be the first thing I would do. If any look bad, you might try to clean them, I used a wire brush on mine w/ no ill effects so far (my bike was missing, popping, and backfiring BAD), but some have said that a wire brush wears the iridium or something off the plugs.
A soft brass brush is recommended.
 

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Honda has a cylinder problem

I've seen a few posts that reference engine noise. Took my 06 VTX 1800 in to adjust the valves so that my noise would stop. Turns out the cylinder (front) is being scalped. It is scored badly, and the sound is apparently piston slap. Honda would not cover the damage as I am out of warrenty, but since taking the bike in, several more shadows and VTXs have reported the same problem. I think a recall is in order and would like to know if others have run into this problem.

Thanks.
 

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Heard a clunk coming home from town just last week. Took me quite a while to figure out it was a bottle of wine in my gearsak hitting my lunchbox when I went round a corner.
 

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noise

I think you should do what Bubba 1800 suggested increase your idle and see if the noise goes away. Back five years ago mine was making a "ticking" sound from the front cyl. carried it to the stealers that didn't have a clue and come to find out on my own my idle was set to low and it went away. I would least try it before i started thinking i needed a engine over haul.
 

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Have you changed the spark plugs? Don't bother with the Iridium. They foul just as fast as anything else and Honda is super proud of them. Try BKR5EIX-11. You should be able to get them at the Honda shop or a parts store.
Basically this is a bad idea (not bothering with Iridium), the Iridiums have been proven to be a better plug.
You can get the recommended plugs at an auto parts store much cheaper than at a Honda dealer, but you should stick with the Iridiums.
 

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I've seen a few posts that reference engine noise. Took my 06 VTX 1800 in to adjust the valves so that my noise would stop. Turns out the cylinder (front) is being scalped. It is scored badly, and the sound is apparently piston slap. Honda would not cover the damage as I am out of warrenty, but since taking the bike in, several more shadows and VTXs have reported the same problem. I think a recall is in order and would like to know if others have run into this problem.

Thanks.
First I've torn down a few motors. They all have gailing and piston scoring. I thinking this is common in all vtxs. The effected area is the exhaust side of the pistons in all cases that I've seen.

Now to the problem with the chug or irregular rhythm. I have seen this before and it's been plugs or a plug that is fouling. Pull your plugs and check them or replace them with new ones. Your bike will run better I sure. If you have an after market fuel management system like the Cobra 2000...take it out and through is away.
 

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The book says the idle should be set beteen 700 and 900 rpms. I have mine set at around 950. It runs at 1,000 or a little over when it's cold. The good thing is that I have a tach so at least I know I'm in the ball park.
 
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