Misfire at steady cruise

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I would love the opportunity to compare to another FJR and if I could find one close.

I am considering the PC III option. Like I said, if I spray carb cleaner lightly right in front of the air intake or in the vicinity of the TB's (when I had the air box out) it smooths out a lot. But cranking the CO numbers way up (+50 or more) doesn't affect it much if any. I'm not sure what overall percentage of the fuel air ratio the CO trim actually translates to though.

It's hardly noticeable at warm idle, cold idle much more so until it goes into closed loop operation. I can feel it a low speeds such as idling around a parking lot, and I can hear it in the exhaust ALL the time at light loads, very noticeable driving around the neighborhood, but not imperceptable at highway speeds either. When the Staintune exhaust was on it I could really hear it. Stock exhaust at least makes it less noticeable. The clunk you mentioned happens only in conjunction with a backfire/spit out the TB, noticed that when the air box was out, but I don't hear the backfire when the air box is in place, it gets dampened. This only happens one in blue moon though (>1%) when warming up, not like it backfires constantly. Lean mixtures burn slow and can ignite the incoming charge during overlap causing a backfire out the intake. I've seen this hundreds of times tuning dirt track engines, seemed to fit the symptoms here as well.

It's not un-rideable and it goes like striped ape (will pull the front wheel without effort), it just drives me nutty. I have a habit of obsessively listening to exhaust sounds on the alert for trouble. Flying clapped out Cessna 182's for skydivers does that to you. I may just be over sensitive to an FJR thing. When I bought the bike, it was in KC, 90% of the test riding was on the interstate. I didn't even notice this until after I got it back to Nebraska (200 miles) and started commuting in town with it. Now I can't NOT notice it :(

 
BustanutJoker hasn't been anywhere near your bike, has he?

Kinda sounds like the infamous "BustanutJoker Tailpipe Sodomy Syndrome" if you ask me.

:assassin:

 
Still sounds like the lean surge. Mine does it a lot if I hold the throttle steady, and cruise. So I try not to do that. It seems to happen at a certain light load, so try to up or down shift to change the load. I vary my speed up and down slightly. It also seems not so noticeable at 80 MPH. B)

 
Appears to me you have more smarts and equipment than most Yamaha shops - taking the bike in might be a huge mistake.

When KrZy8 is up running again I'll take some VA so you can see/hear another stock 06 sounds.

 
@Smerkal - Yes, all you say still sounds like "normal" to me. Installing a PCIII (or V) with a good map will smooth out the lean stumble at cruise, but the miss at idle will continue. I've also tried adding to the CO but that still doesn't ever result in a completely smooth idle.

One other "feature" that will add to the exhaust popping noise is the PAIR system. As you may already know, it intentionally injects fresh air into into the exhaust stream under certain circumstances, in an effort to get more complete exhaust vapor ignition in the cats. Most people who have aftermarket exhaust cans will remove the PAIR system and install block off plates to eliminate the (more obvious) popping. I installed the block offs when I did my first valve check (it mostly all had to come out anyway).

 
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I went through the same issue with my '09. It is a lean misfire. I ended up buying a PCV with the Autotune module. Problem solved.

A useful feature of the PCV is the "cell trace" which shows you the affected fuel table cells real time. With the bike on the center stand you can rev the motor to where the stumbling occurs and see the cells affected which then you can adjust accordingly. I had a significant lean spot between 3K-4K rpms, probably due to EPA regulations.

Good luck.

 
On my 3rd FJ. Currently at 70k on a 09. Have never experienced a fart, stumble, or any kind of misfire. My ECU will occasionally **** up on a real cold restart, but other than that, no problem. Nothing special about my unfarkled scoot. Here is the biggie - I live at 4500' alt., and usually ride above that. Can't remember being below 3000' on a FJ. Got to be something there. By the way, I get the good mpg.

 
On my 3rd FJ. Currently at 70k on a 09. Have never experienced a fart, stumble, or any kind of misfire. My ECU will occasionally **** up on a real cold restart, but other than that, no problem. Nothing special about my unfarkled scoot. Here is the biggie - I live at 4500' alt., and usually ride above that. Can't remember being below 3000' on a FJ. Got to be something there. By the way, I get the good mpg.
So, apparently you are one of the people that cannot feel it. It's there, believe me.

I have seen more FJRs than I can count and every one of them has the standard stumble at idle.

Here's a

where the owner recorded the stock mufflers and then the sound after drilling out his baffles (Trooper Mod). This has the standard idle burble and misfires when revved, easiest to hear after the mod.
I could go on all day. I'd like someone to post a video of an FJR that doesn't have the lean stumble, and then tell us what the heck you did to get rid of it. :p

 
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I am very interested in this as well. My 05 has a stumble mostly at idle that drives me batty...

I have considered the steps you have tried but as of yet cannot come up with anything either...

 
Fred,

Thanks for the video links.

BTW, the Two Brothers exhaust in the 2nd video sounds like ***. I can't believe folks actually want their FJRs to sound like that! That's tantamount to putting a Honda Civic Fart-Can exhaust on a BMW 6 series. Me No Likey!

 
I agree. But I've heard the 2 Bros exhaust live and in person and it sounded kind of nice and mellow to me. Not anything like the disgusting audio track in that video. So, I have to assume that the sound pickup for that video was FUBAR. Still, I prefer the stealthy stock sound to any volume enhanced growl. :assassin:

Still, the gauntlet has been thrown down! I want to see a video of any FJR that doesn't have the bumpity bump idle.

I recall a smart guy (from somewhere upstate NY maybe?) who did an exhaust gas analysis on his FJR and concluded that at idle it was actually running too rich. :huh: It never seemed to go anywhere from there, and it sure sounds like lean stumble to me, but I'm willing to listen to any and all theories.

 
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Thank you everyone for the input. Fred, the video links are just what I needed. Mine sounds EXACTLY like the stock bike in the second video. So apparently I'm chasing the infamous lean ghost. Glad to have this info and avoid a trip to the local 'Stick it to you' dealer. I wasn't sure what they were going to do that I hadn't already, short of an 4 or 5 gas (which a friend offered to let me use later). I can literally find nothing wrong other than it misses at light load. I will call them in the AM to be sure all recalls have been taken care of though.

I have a PC3 on order. I'll see what that does for me. Between the existing mappings and monitoring the O2 sensor and 4 gas at different rev's, hopefully I can tweak it out. So far, the best solution is what road runner said, just ride it harder ;)

Y'all are a great resource. This forum alone makes me glad I bought the bike. And yes I say y'all even though I'm a Nebraska native......spent too much time in Arkansas as a kid.

I'll report back on how things go later in the week.

Edit: FYI, I really like the StainTune exhaust sound, other than making the miss more evident, but I think the stock is a little more to my liking. I'm getting old I guess. Perhaps I'll offer the StainTune up for sale at a later date.

 
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I seem to recall someone posted the ECM software was changed in '08. Just one data point..... I rode my buddy's '10 to compare with my '07 with PCV, and it did not have any issues requiring a PC in my opinion.

 
Problem Solved!

Installed the PCV from FuelMoto this morning, what a difference. The guys at FuelMoto were out of them when I called Monday, but as soon as they had one they loaded a map and shipped it out, Saturday Delivery even. Started dis-assembly at 0930 this morning, FedEx showed up at 1000 and I was riding by 1100. I also removed the PAIR system and installed the Wynpro block off plates while I was in there. It's truly a different motorcycle. Runs smooth, throttle snatch is all but gone, no more ping, amazing. I'm going to track the mileage and I may add the auto tune module later (lack of $$ now) but so far I'm very happy.

Thanks for all the ideas and suggestions, I'll update after a bit of riding as to how its doing mileage wise, etc.

 
I hate to be smug, but... I told you so!

:p

Glad that you got it sorted out.

As for the fuel mileage, you should be able to retain good fuel mileage with an accurate map. Getting and installing the Auto Tuning option is one way to get one.

I am currently (still) running with a map borrowed from someone else who got it made up on a Dyno, and I know that I am sacrificing a few mpgs because it smells rich in some conditions. I keep meaning to get the bike over to a local shop that has a Dyno and having my own map made up, but I am too much of a procrastinator when the bike is running so well already. ;)

 
I've always wondered if 10% ethanol in the fuel isn't the cause. The bike was engineered and tested in Japan where there may not be ethanol in the fuel.

 
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