Am I running too lean? Why?
Club Member
Joined: May 2007
Posts: 145,895
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From: 40 miles Northeast of Indy..
If you've changed pipes/mufflers AND air cleaner, you need a stage 1 tune or flash. Changing one or the other isn't a big deal, but once you open up both ends with more air, it needs the ECM set to the proper levels for the air/fuel mixture.
At least, that's how it's been explained to me.
At least, that's how it's been explained to me.
Please read the OP a little better...
Stellar HDF Member
Joined: Feb 2010
Posts: 3,395
Likes: 266
From: Southern California
Well let's see . . . the problem didn't exist before the Air Cleaner and the Spark Plug changes. The Air Cleaner correction/repair, if it did anything at all would have made the mixture ever so slightly richer. Therefore, I suspect that the Autolite Spark Plugs you installed probably have too high of a heat range. I would suggest that you try a set of original equipment spark plugs and see what that does for you. Before installing the new spark plugs you may also want to closely inspect where the spark plug seats against the cylinder head. Make sure it is perfectly clean and to use a torque wrench when you install the new spark plugs. BTW, the coloration of the spark plugs in your pictures looks pretty good actually. I don't see any splash deposits or glazing that would indicate either a lean or a serious overheating problem. Probably just a couple of heat ranges to high. Sometimes a manufacturer will do that to compensate for what they perceive to be a fouling problem. Since many folks run their bikes way too rich in a search for additional power, I can see why Autolite might do this.
Seasoned HDF Member
Joined: Aug 2007
Posts: 21,732
Likes: 17,569
From: Driftless Area
Nobody else has said this yet......Put a 175 or 180 main jet in that carb. Most bikes came 165 main jet and they were already marginally lean on a stock bike. With the air cleaner and pipes you got, you need to fatten the air/fuel mixture a little.
Ultimate HDF Member
Joined: Jan 2008
Posts: 7,476
Likes: 5
From: Republic of Texas
We have a winner. Rejet to 175 or 180. Quick fix is higher octane gas less wick twist. I am not going to bother commenting on plug brand choice. Maybe you work for ford. Both of my bikes are tuned fat.
Road Master
Joined: Jan 2011
Posts: 893
Likes: 0
From: Knob Noster, MO
+1 one, those plug pics have some light detonation showing. I see the build up of metal ***** on and around the ceramic. Also the ceramic looks to be chiseled somewhat instead of smooth like normal. So to the OP you are right about the pinging I can see it on your plugs. Swap to a bigger main jet and that will fix your problem. Start with the 175 and go from there. But I would do some research and make sure your plugs aren't too hot, are they labeled as stock heat range? If so you are ok, you don't want to hot of a plug or too cold of a plug. For your minimal mods (no motor work) you can stick with the stock heat range.
Tourer
Joined: Nov 2011
Posts: 324
Likes: 1
From: USA
I would check the pilot jet for any obstruction (hold it up to a bright light and look through the hole).
I agree that the main jet should probably be a little fatter, but the main jet has little or nothing to do with lean condition at idle and low rpm.
I agree that the main jet should probably be a little fatter, but the main jet has little or nothing to do with lean condition at idle and low rpm.
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Outstanding HDF Member
Joined: Mar 2010
Posts: 2,965
Likes: 384
From: SoCal hi desert
Thanks for all the input. I think I figured it out tonight.
Someone in the past removed the vapor canister from under the seat but neglected to plug the hose going to the carb. I hadn't noticed this before since it seemed to run ok but it was always a little flat for power and the idle seemed to be too high but wouldn't adjust down so I wrote it off to maybe the VOES or something.
Really poking around with the carb led me to look at all the possible vacuum sources and that's what led to finding the vapor canister line wide open. Plugged it, put it all back together, and rode it around the block. Starting was much better and off idle power seems definitely improved. We'll see what it does when it warms up a bit outside.
Again thanks for all your input.
Someone in the past removed the vapor canister from under the seat but neglected to plug the hose going to the carb. I hadn't noticed this before since it seemed to run ok but it was always a little flat for power and the idle seemed to be too high but wouldn't adjust down so I wrote it off to maybe the VOES or something.
Really poking around with the carb led me to look at all the possible vacuum sources and that's what led to finding the vapor canister line wide open. Plugged it, put it all back together, and rode it around the block. Starting was much better and off idle power seems definitely improved. We'll see what it does when it warms up a bit outside.
Again thanks for all your input.
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Outstanding HDF Member
Joined: Mar 2010
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From: SoCal hi desert
Update: I put a couple hundred miles on it since I plugged the vacuum leak. Checked the plugs last night and they look pretty much the same. I went back over all the suggestions here re jets and plugs. The Autolites I bought are the wrong number according to the online catalog. It should have 4265's but some how I ended up with 65's. I don't know the difference. the heat range should be the same but they aren't the right # so I'm going to get some new ones today fr the dealer. I bought a 180 main but haven't put it in yet-going to change one thing at a time.
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