pebble in a beer can noise at 70 mph . . .help!
#1
pebble in a beer can noise at 70 mph . . .help!
Hey forum,
need some expert advice.
I have a 2000 electraglide classic. I decided to do an upgrade following a bunch of problems with my TC88, namely several headgasket leaks. Rather than spend the money getting the decks and heads milled, I decided to do a full top end rebuild. I used S&S 95' jugs that were re-honed by my local cycle shop; for pistons, I used Screaming Eagle 95' pistons; the build was topped of with a pair of stock heads; and a relatively new CV carburator. The lower end had approximately 60,000 miles on it when I had screaming eagle 203 cams and new tensoner shoes installed on the bike.
Here is the link to the video of the noise
You Tube
The motor went together very well. Most of the equipent went together fine. The only modifications that I mad was to plosh up the ports a little.
Well, I took the bike on 5700 mile treck across the US. From the beginning of the trip I got a pinningin in what appeared the front cylinder at 60 miles per hour. It was very wll pronounced sound. Not the regular valve chatter that is uniform across all normal speeds. Throughout the trip, I adjusted the carb (enriching and leaning it out) nothing worked. It sounded like a pebble in a beer can. Sometimes it would get more pronounced on acceleration. Then at other times, The engine would ping at only 70 mph. I chased this noise for the whole trip.
I dont know what i should do. The bike is carburated. Overall it ran fine no mechanical issues at all. Plenty of accleleration for the whole trip. Although it does have a vibration now at 70mph. Any ideas? I thought it was pre ignition frirng but I really dont know. Any good advice would be greatly appreciated.
Thanks
need some expert advice.
I have a 2000 electraglide classic. I decided to do an upgrade following a bunch of problems with my TC88, namely several headgasket leaks. Rather than spend the money getting the decks and heads milled, I decided to do a full top end rebuild. I used S&S 95' jugs that were re-honed by my local cycle shop; for pistons, I used Screaming Eagle 95' pistons; the build was topped of with a pair of stock heads; and a relatively new CV carburator. The lower end had approximately 60,000 miles on it when I had screaming eagle 203 cams and new tensoner shoes installed on the bike.
Here is the link to the video of the noise
You Tube
The motor went together very well. Most of the equipent went together fine. The only modifications that I mad was to plosh up the ports a little.
Well, I took the bike on 5700 mile treck across the US. From the beginning of the trip I got a pinningin in what appeared the front cylinder at 60 miles per hour. It was very wll pronounced sound. Not the regular valve chatter that is uniform across all normal speeds. Throughout the trip, I adjusted the carb (enriching and leaning it out) nothing worked. It sounded like a pebble in a beer can. Sometimes it would get more pronounced on acceleration. Then at other times, The engine would ping at only 70 mph. I chased this noise for the whole trip.
I dont know what i should do. The bike is carburated. Overall it ran fine no mechanical issues at all. Plenty of accleleration for the whole trip. Although it does have a vibration now at 70mph. Any ideas? I thought it was pre ignition frirng but I really dont know. Any good advice would be greatly appreciated.
Thanks
#2
First, the disclaimer; I am not an expert.
What pistons; cast or forged? flat top or domed? What clearance was used to fit the piston to the cylinders? How does the motor sound on a cold startup?
Detonation under acceleration or load, as in lugging, would indicate that the advance curve was too aggressive but ping at cruise in an unloaded condition would indicate that the initial timing is to advanced. Are you running the stock ignition?
You also mentioned that the heads were milled; how much? Since the last thing you did was a top end rebuild I would start with a compression and leak down test to check the condition of the top end; that will give you a place to start.
What pistons; cast or forged? flat top or domed? What clearance was used to fit the piston to the cylinders? How does the motor sound on a cold startup?
Detonation under acceleration or load, as in lugging, would indicate that the advance curve was too aggressive but ping at cruise in an unloaded condition would indicate that the initial timing is to advanced. Are you running the stock ignition?
You also mentioned that the heads were milled; how much? Since the last thing you did was a top end rebuild I would start with a compression and leak down test to check the condition of the top end; that will give you a place to start.
Last edited by djl; 08-20-2011 at 02:46 PM.
#3
#5
DJL I used cast SE Pistons. The jugs were honed by a highly reputable indy shop. I do have the stock ignition in the bike. The only upgrade I made was the pistons and jugs. I had new cams put in while the timing shoes were being replaced because they were worn out. The strang thing is that the bike never made this sound when I had the 88 jugs on. but that is allI really changed.
Soft 02 Is it the outer linkage or inside the transfer case?
qtrracer. I checked everything. My exhauset pipe was little crooked. I orginally thought that may be the problem.
The strage thing is that it seems to only mae the noise at abot 70 mph and I liitle over. I thouoght it may be a collapsing lifter, but it seems to be comming form the promary side up front.
Soft 02 Is it the outer linkage or inside the transfer case?
qtrracer. I checked everything. My exhauset pipe was little crooked. I orginally thought that may be the problem.
The strage thing is that it seems to only mae the noise at abot 70 mph and I liitle over. I thouoght it may be a collapsing lifter, but it seems to be comming form the promary side up front.
#6
#7
I'd do a chop test on the plugs.
1. find an open road (no cops)
2.do a little drag race
3. wind it up in each gear
3. keep it at top end for a short while
4. Pull in the clutch (after releasing the throttle)
5 Turn off the ignition (Important! engine running will change reading) and spoil the test.
6. Coast to a stop (keep clutch in)
7. Pull the plugs and read them Light choc is the color your looking for.
DO NOT DECELERATE, THE ENGINE MUST BE SHUT OFF!! FOR THIS TO WORK!!
Have an extra set of plus in case you break one (experience)
This will give you a quick assessment of your fuel curve. Lean or Fat.
I would also put a manual read oil gauge on it and check the pressure at this speed. At 70 mph all the oil can't go through the filter and a bypass spring opens up to make sure the oil does starve.
I agree with the rest, it seem like a harmonic issue, something loose.
1. find an open road (no cops)
2.do a little drag race
3. wind it up in each gear
3. keep it at top end for a short while
4. Pull in the clutch (after releasing the throttle)
5 Turn off the ignition (Important! engine running will change reading) and spoil the test.
6. Coast to a stop (keep clutch in)
7. Pull the plugs and read them Light choc is the color your looking for.
DO NOT DECELERATE, THE ENGINE MUST BE SHUT OFF!! FOR THIS TO WORK!!
Have an extra set of plus in case you break one (experience)
This will give you a quick assessment of your fuel curve. Lean or Fat.
I would also put a manual read oil gauge on it and check the pressure at this speed. At 70 mph all the oil can't go through the filter and a bypass spring opens up to make sure the oil does starve.
I agree with the rest, it seem like a harmonic issue, something loose.
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#8
DJL I used cast SE Pistons. The jugs were honed by a highly reputable indy shop. I do have the stock ignition in the bike. The only upgrade I made was the pistons and jugs. I had new cams put in while the timing shoes were being replaced because they were worn out. The strang thing is that the bike never made this sound when I had the 88 jugs on. but that is allI really changed.
I listened to the video/audio again, several times, and what I am hearing when you move the mic toward the front cylinder sure sounds like detonation to me. Get a bottle of octane booster, dump it in and see if the detonation goes away. You could also drop down two heat ranges in plugs; tha helped my situation but did not eliminate the detonation and I had to change cams.
I don't disagree with the suggestions to check all the possibilities of something loose bouncing around but what I hear sounds like detonation.
#9
#10
I agree with djl. The more I listen to it it sounds like classic deto. Are you running the stock needle in the cv carb? If so I would change it out for the sporster needle to richen up that cruising area of the fuel circuit. Also at cruising speed and light throttle settings you are running alot of ignition advance. A 95" big bore with 203 cams I would think would definitely need a little more fuel as the stockers are on the edge of too lean when at light throttle. I'm sure djl or someone else may be able to get you the part number for that jet needle.