Author Topic: Bike runs terribly. Any suggestions?  (Read 3780 times)

Offline YankeeInTX

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Bike runs terribly. Any suggestions?
« on: January 01, 2014, 10:37:02 pm »
Hello All,
  I'm running out of ideas and hope that someone can help.  At this point any idea on what to do next would really be appreciated.  I have a 2001 Concours C10 with about 18,000 miles on it that I bought about a year ago.  For the first 5000 miles the bike ran great, and got very consistent fuel economy (38-40 mpg).  Then i decided that it was due for a valve adjustment.  Honestly, i wasnt looking forward to doing it the first time, and the bike sat for about 3 months while i procrastinated.  Then i finally got around to it, and the bike has run very poorly across the whole rev range ever since.  Since the valve adjustment I've chased after anything I could think of and have done the following:
1) I had someone pull and clean the carbs, thinking that they were gunked up from my procrastination.  They definitely had some gunk, but the bike did not run much better after the carb clean.  It started much easier, and continues to start easily.
2). I've ridden only about 100 miles or so, because I'm really not sure if I'm doing damage to something because I don't know what's wrong.  But in that time I've noticed that i get about 15mpg, and very reduced power.  I can completely open  the throttle on the highway in top gear and get to a max speed of 75 mph on level ground.  I need to slip the clutch coming away from a stop sign or I'll stall.  The idle is pretty rough, like what I'd expect to hear if 3 cylinders (or 2) were firing.  Come to think of it, the power it's making is like only 2 or 3 cylinders are firing.
3) I rechecked the valves today.  They were fine. I realized that I had reversed the polarity on the coils when i put stuff back together last time, though.  For some reason on my bike the red wire leading to the coil is negative but i had assumed that it was positive.  I put it back correctly this time (used a multimeter on the wires to ensure that I had it right) but it didn't make a difference. Still very low power and 15 mpg on the highway.
4) I changed the spark plugs.  The old ones were very blackened (all 4, equally), which makes sense because the bike is definetly running very rich right now.  I don't know why, it didn't when it was running well, but you can smell strong raw gas in the exhaust.  The bike ran 5% better with new plugs, and still runs terribly.
5) My left exhaust can used to be shiny chrome.  In the last 100 miles it was turned blueish.  The right muffler still is shiny chrome.  Any idea why one can turned and the other didn't?  I feel strong and equal exhaust flow from both mufflers.
6) At the time of valve adjustment i also added an inline fuel filter.  I don't think that this is a fuel starvation issue, though.  The bike is running rich, and it runs terribly from the time that i start it.  "Prime" for 15 seconds doesn't change anything.  I'm assuming that if the fuel filter wasn't flowing enough fuel the bike would run fine for the first minute, and it wouldn't make the bike run rich.
7) I checked my air box and filter.  Nothing out of the ordinary.  No family of mice, gerbils, or deer have decided to move in and choke the air flow.  Previous owner put in a K&N, but I don't think it's related to the problem because the bike was previously running great with it.
8) While the tank was off I tested for damage from hydrolock using the methods posted by Steve In Sunny Florida (Shoodaben Engineering) on YouTube.  The pistons are right where they should be, no bent rods.

So, does anyone have any ideas on what to do next?  I'm thinking that since all 4 spark plugs were black that helps narrow it down (it's not one bad coil or one carb that's resistant to cleaning).  This is the only time that I was actually hoping to find a family of 12 mice in my airbox....  Thanks for any suggestions.

 - Adam

Offline Furbo

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Re: Bike runs terribly. Any suggestions?
« Reply #1 on: January 02, 2014, 03:47:59 am »
Adam,

I have 3 guesses....

1 - you've botched the valve adjustment and their too tight

2 - you've got the plug wires mixed up - have done it myself. One coil fires cyl 1&4, the other 2&3. Additionally, sometimes they dont go on all the way.

3- as a result of the pieces removed and replaced somethings either blocking hte air intake, or the chokes been permanently turned on.

It's something simple - but those type of things are often hard to spot.
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Offline alanjw

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Re: Bike runs terribly. Any suggestions?
« Reply #2 on: January 02, 2014, 07:05:51 am »
do all the exhaust pipes get hot ? if not i think i d go with the carbs again ,also i d take off the fuel filter as they can rot inside and their innards go into the carbs also they sometimes dont flow enough fuel ,
just go back over whats been done and check things

a friend of mine has a gpz900 (zx900) he went onto reserve ,sucked a load of c**p through and managed 67 miles to the TANKFUL ,cleaned his carbs out and no problem

Offline Steve in Sunny Fla

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Re: Bike runs terribly. Any suggestions?
« Reply #3 on: January 02, 2014, 07:37:26 am »
I think the plug wires are in the wrong order. the left coil goes to cyl 1 - furthest left, and cyl 4 - furthest right. the right coil wires go to the 2 middle cyl, 2 and 3.

BTW the black plugs could also be from water in the gas.  Steve

Offline YankeeInTX

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Re: Bike runs terribly. Any suggestions?
« Reply #4 on: January 02, 2014, 12:30:30 pm »
WOW!!!!  Thank you all so much for the quick and accurate replies.  I gave you a long rambling story of EVERYTHING that I thought might be relevant, and you nailed it.  Here's the conclusion:

I woke up this morning and looked online, fully expecting that I probably would not have any replies from overnight.  3 replies.  So far 2014 is looking pretty good, right?  Upon reading them I realized that I'm pretty sure that I had plug wires #1 and #2 on the left coil, with #3 and #4 on the right coil.  Went out this morning (it was 42 degrees out, I was motivated) and tore into the bike one more time.  Furbo and Steve were absolutely correct, and alanjw's suggestion to go back over what I did before also counts as the right solution.  I don't know if I ever would have solved this without you guys.  My bike was running on 2 cylinders getting spark at the right time.   Immediately after making things right the bike ran more beautifully than it has since I got it.  I suspect that has to do with the new spark plugs and carb cleaning in the last 100 miles, or it might just be that it is so much more incredibly powerful than the 499cc twin cylinder Concours that I had yesterday.  That being said, when I got it I remember that there was nothing that I could do to get the front wheel in the air.  5 minutes ago a healthy whack open of the throttle was getting the front tire skimming off the pavement.  I'm not looking to start stunting a 670lb bike, but this engine really feels stronger than I've ever felt it before.  Mystery solved!  The blackened spark plugs I'm chalking up to anything that happened in the last 18,000 miles.  It's possible they're the original plugs.  Unless I run into more problems I'm going with Steve's thoughts about water in the gas, and thinking that whenever it happened it's not relevant to right now.

Thank you.  Thank you for being right.  Thank you for solving in one day what I found impossible to solve for the last few months.  No joke - a week ago when I was ripping my hair out my wife actually said to me, "You know honey, maybe you just got a lousy bike.  It's ok.  Can you sell it?"  I'm still cringing.  Air, fuel, compression, spark, right?  Not an infinite list of things that could go wrong... 

I don't know how I can repay you.  My useful skills include being a high school Math teacher for a dozen years (everything from Algebra I up to AP Statistics), and I'm 1 semester away from completing a Master's in Statistics.  If my set of skills can be as useful to you as your set of skills was to me I would feel great about it.

Offline Steve in Sunny Fla

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Re: Bike runs terribly. Any suggestions?
« Reply #5 on: January 02, 2014, 12:36:06 pm »
do yourself a favor and Join COG.

BTW, the blue muffler was the giveaway... Steve

Offline Ron Dawg

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Re: Bike runs terribly. Any suggestions?
« Reply #6 on: January 02, 2014, 03:34:12 pm »
Awesome.

Steve, you're da' man (again).

To the OP: welcome to the C-10 world. These guys are great. Glad your problem is done. (Listen to Steve).

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Offline SteveJ.

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Re: Bike runs terribly. Any suggestions?
« Reply #7 on: January 02, 2014, 03:36:43 pm »
Quote
I don't know how I can repay you.  My useful skills include being a high school Math teacher for a dozen years (everything from Algebra I up to AP Statistics), and I'm 1 semester away from completing a Master's in Statistics.  If my set of skills can be as useful to you as your set of skills was to me I would feel great about it.

You could host a tech session or Ride To Eat somewhere.  :thumbs:
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Offline 2fast

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Re: Bike runs terribly. Any suggestions?
« Reply #8 on: January 02, 2014, 05:59:25 pm »
You can always "count" on COG! :nuts:
Brian in Minnesota
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Offline Nosmo

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Re: Bike runs terribly. Any suggestions?
« Reply #9 on: January 02, 2014, 07:35:35 pm »

I don't know how I can repay you.  My useful skills include being a high school Math teacher for a dozen years (everything from Algebra I up to AP Statistics), and I'm 1 semester away from completing a Master's in Statistics.  If my set of skills can be as useful to you as your set of skills was to me I would feel great about it.

Perfect!  67.8 % of us love to argue about statistics and the other 39 % can't do math.
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Offline cmoore

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Re: Bike runs terribly. Any suggestions?
« Reply #10 on: January 03, 2014, 05:34:25 am »
Yep, join COG. This forum has been helping me keep my '02 rolling for almost 10 years now. Never been in the shop for anything mechanical. Good people here. 8)
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