|Posted on Wednesday, February 16, 2011 - 10:00 am: ||
Back in June 2010 I posted about the noise my í05 Buell XB12R was making. I was led to believe that it was the conrod bearings so I decided to strip the engine to check while I waited for a replacement engine to appear on ebay, this being the cheaper, quicker and more definite option. Pulling up and down on the conrods revealed no play and a replacement engine has yet to show up on Japanese Ebay (Yahoo auctions). So the bike sits there in pieces with spring approaching.
I donít have the time, tools or skills to measure every other part with a micro meter.
So my plan now is to replace the rocker arm shafts, rocker arms and piston rings, zip it back up and hope for the best. Before I do Iím looking for a last opinion.
Considering the Harley push-rod lump is so common and much loved, IĒm sure there are plenty of people out there who could take one listen to my video and tell me exactly what the problem is. Maybe I hoping for too much but its worth a shot.
Below is a description of how the bike was performing before I pulled it apart and a link to the Youtube video. Iíll be posting this on a few different forums so apologies if you see it again. I hope you guys can help before Iím forced to by a Honda or something like that. Cheers, Paul.
The bike (Buell has 38,000km on it (23,000 mikes) The bike was running great, except for the new noise, with smooth idle and acceleration. The noise has a rhythm that gets faster with engine speed. At idle it sounds like someone shaking some toothpicks in a tin about once every second, chic ka(pause)chic ka(pause)chic ka etc. At 3000rpm its up to four times a second. The noise speeds up as the engine speed increases but it is still slow enough to count the individual 'pulses' right up until about 5000rpm. I had the primary chain checked at the dealer and he said its fine and to ride it and see what happens. The bike was running fine and didnít make the noise while rolling with the engine off. The noise appears to be coming from the top of the front cylinder as you can hear in the video. In hindsight I should have ridden it a bit more before stripping it down but at the time I was worried about it leaving me stranded or worse.
Link to you tube Video.
Link to original post:
|Posted on Wednesday, February 16, 2011 - 10:36 am: ||
Damn Paul don't sound good does it.
Sorry I'm no help.
Isn't there a huge Buell following in Japan?
Hope you're fixed up soon.
Please keep us up to date.
Your BadWeB link is broken
|Posted on Wednesday, February 16, 2011 - 10:37 am: ||
|Posted on Wednesday, February 16, 2011 - 10:50 am: ||
it doesn't sound healthy, if it were still together, you could take a screw driver and put the handle end to your ear and the other end to spots on the engine and listen, kinda like a red neck stethoscope,
|Posted on Wednesday, February 16, 2011 - 11:35 am: ||
From the video the noise sounds more pronounced in the top at the heads. Possible pushrod or rocker going out maybe. If it's the pushrod I would think that one of your hydrolic lifters went out or is going out and not staying pumped up.
(Message edited by cataract2 on February 16, 2011)
|Posted on Wednesday, February 16, 2011 - 12:29 pm: ||
One thing to check (haven't deeply listened to the video, sorry) that I experienced on my 1995 S2 (hey, it's an air head too!) is the pushrods and rocker arms. It should be easier to visually check the pushrods. Look at the area of the pushrod that interfaces with the rocker arm and it should be nice and spherical. If they are cone-shaped (from the rockers hammering on them) they need to be replaced- along with the rockers for good measure. I'd probably replace the lifters at the same time as well.
Keep us posted with what you find,
|Posted on Wednesday, February 16, 2011 - 01:09 pm: ||
Since you will be replacing the rings, might as well pull the valve train apart and look at each piece. I would pull the lifters while you are doing things and take a look at the cam lobes. While doing it you might want to look at the oil pump gears.
If you haven't, check the piston skirts for wear marks, that might tell you about a bent con-rod, bad pin, or just whacked piston.
You can get used crank/rods on ebay for $100 or less, I'm sure someone would be willing to ship to you and the shipping shouldn't be too much. Have it lightened and balanced and a new big end bearing installed while they have it apart.
I need to start tearing into mine to find the tapping noise, pretty sure it is a lifter gone bad.
|Posted on Wednesday, February 16, 2011 - 05:15 pm: ||
My wager is that the problem will be found in the cam cover somewhere.
Sounds to me like a bad bearing rotating.
Perhaps cam-follower needle bearing or a cam bearing itself.
I say this because that's what happened to my 1979 sportster engine.
Little bearing chunks went into the oil pump
|Posted on Wednesday, February 16, 2011 - 09:42 pm: ||
The rhythm doesn't sound right to be valvetrain; it doesn't "match". Think music - if the engine is making regular 4-beat time...the noise you're hearing is like a waltz, a 3 count. Doesn't match up. The (pause) that you mention...shouldn't be there.
You say you pulled it apart? What did the piston skirts look like? Did it look like they were scarred up from sliding up and down the cylinder bores 'crooked'? The only part of the piston that should touch (and show any wear) is the rings; if the piston itself is touching and showing marks, you have an alignment problem, either at the wrist pin or at the flywheel.
Do the pistons "twist" on the end of the rods any? Or can you wobble the piston on its wrist pin at all?
Do the rods move SIDE TO SIDE at all?
If it were me...I'd check the primary chain, tension, and adjuster shoe. Could be just the chain slapping the inside of the primary case. That (pause) in the tic-toc is what gets me....
|Posted on Thursday, February 17, 2011 - 06:03 pm: ||
A roller bearing's rollers make a lap at 1/2 the RPM of the shaft, right?
Let's say one is bad, shaped wrong.
It's not going to make noise until it's under load. The cams are really only under load when pushing a valve open.
That's my train of thought.
|Posted on Friday, February 18, 2011 - 11:46 am: ||
Based purely on the nature of the sound, I'm with Rat on this one. The sound the way it echoes and reverberates appears to be coming from a hollow area with some air volume not a tight spot like where the cams live. Also, if I heard it correctly, it seemed like the "tapping" frequency did not go up as the engine speed was raised. Just my 2 cents.