07, 17K miles, 3K RPM Surging...

[jeremybhm]

My bike just rolled over 17K miles this week on the way to Florence, AL. I've noticed a surge that developed a few thousand miles ago. I figured it just needed a TBS and was going to take care of it at the next oil change. Well, it started to get annoying, so I tore it down this afternoon and hooked up my mercury carb tuner. I don't think the sound on the video captures what I was trying to, but I attached it anyway. What should I check next? The TBS is hard to nail down the way it's acting, because it won't stay at a stable level. As you roll through the RPM range, the cylinders change in relation to each other in addition to the normal vaccuum change. Sometimes, around 3-4K, the mercury will be even all the way across, sometimes, pistons 1 and 4 are higher than 2 and 3. In the higher range, it runs great. It's just when cruising in traffic that it seems to miss or stutter.

I've ordered a new air filter to put on at my next oil change, but it wasn't that dirty the last change(around 15K).

I have the 'fixed' 07 ECU

Barbarian Mod +7

What should I check/change next?

 

[jeremybhm]

for some reason the photobucket link doesn't work, so here's the direct link

video link

 

[Subcritical]

My bike just rolled over 17K miles this week on the way to Florence, AL. I've noticed a surge that developed a few thousand miles ago. I figured it just needed a TBS and was going to take care of it at the next oil change. Well, it started to get annoying, so I tore it down this afternoon and hooked up my mercury carb tuner. I don't think the sound on the video captures what I was trying to, but I attached it anyway. What should I check next? The TBS is hard to nail down the way it's acting, because it won't stay at a stable level. As you roll through the RPM range, the cylinders change in relation to each other in addition to the normal vaccuum change. Sometimes, around 3-4K, the mercury will be even all the way across, sometimes, pistons 1 and 4 are higher than 2 and 3. In the higher range, it runs great. It's just when cruising in traffic that it seems to miss or stutter.
I've ordered a new air filter to put on at my next oil change, but it wasn't that dirty the last change(around 15K).

I have the 'fixed' 07 ECU

Barbarian Mod +7

What should I check/change next?

Hi Jeremy. Quite a few people have the same problem that you are describing. I'm new to all this, and just picked up a brand new 08 FJR last Friday. It ran as smooth as glass at low RPM when I first got it. At about 300mi, it started surging and running uneven at low RPM's (below 4000rpm).

I ordered a carbtune and I'm going to check out the sync when it arrives.

Hopefully that smooths out the uneasiness in the low rpm.

I don't have any advice, but hope you get it ironed out. The FJR is a great bike other than this issue

 

[jeremybhm]

Hi Jeremy. Quite a few people have the same problem that you are describing. I'm new to all this, and just picked up a brand new 08 FJR last Friday. It ran as smooth as glass at low RPM when I first got it. At about 300mi, it started surging and running uneven at low RPM's (below 4000rpm).
I ordered a carbtune and I'm going to check out the sync when it arrives.

Hopefully that smooths out the uneasiness in the low rpm.

I don't have any advice, but hope you get it ironed out. The FJR is a great bike other than this issue

Well, mine went 15K miles without this issue, so something has to have changed. Either a spark plug, spark plug wire, fuel injection, or air flow, but I'm not sure what to do first.

I have considered getting a PC3 anyway, to smooth out the off-idle response in the twisties, but I'd rather get this resolved first before I add in something else.

I think I'll undo my +7 on the barbarian mod when I get home and see if that makes a difference.

 

[jeremybhm]

OK CO settings don't seem to make it better. Going down makes it worse, going up, doesn't make any difference.

Ideas? SkooterG, somebody???

 

[CHRIS_D]

I would first check your spark plug condition. Maybe this way you can get it down to which cylinder is a problem.

If the plug and wires look good check for any vacuum leaks, including around the map sensor.

 

[gr8eyes]

Spark plug wires or fouled plug in 1 cylinder?

 

[7xray]

My '07, 5000 miles, has done this since the beginning. At 3000 rpm it feels a little like a wind buffet. Had TBS done at 4000 without any change in the "surge". I'll be interested in what you find out.

7X

 

[jeremybhm]

I just put a set of new NGK plugs in and verified that each plug is firing. No change. I hooked up my sync tool, and it just floats all over the place. It won't hold a steady vaccuum for anything.

What's the best way to check for vaccuum leaks?

I ran by Big #1 in Homewood to get the plugs and got one of their service guys to listen to it. He said they'd have to hook it up to the computer to try and diagnose it and it would be the end of next week before they could get to that.

 

[jeremybhm]

Ok. I went through the service manual diagnostic tests and all the sensors, fuel injectors, etc check out fine. I'm back at my factory CO settings as well.

I've been doing some reading about vacuum leaks and some articles suggest using carb cleaner/starter fluid or some other flamable liquid to try to find a vacuum leak. I'm not sure I just want to spray that stuff down into my engine compartment while the engine is running. The idea is that if there is a vacuum leak, it will siphon the fluid in, and smooth out the idle as it gets additional combustible material...

Any thoughts on this?

 

[03HiYoSilver]

Jeremy,

You may want to check this out...same symptoms happened to me:

https://www.fjrforum.com/forum//index.php?s...st&p=267606

and if you have not checked out your air filter, take a look at it as well.

Good Luck.

 

[jeremybhm]

Jeremy,
You may want to check this out...same symptoms happened to me:

https://www.fjrforum.com/forum//index.php?s...st&p=267606

and if you have not checked out your air filter, take a look at it as well.

Good Luck.

No change after replacing air filter. I'm going to have to find that wiring harness and check it I guess.

 

[jeremybhm]

03HiYoSilver , the connector that you had issues with doesn't seem to exist on the GenII's. The wires come out of the coil packs and go straight into the bundle that goes back to the ECU...

 

[03HiYoSilver]

Jeremy,

Thanks for the reply...No Main Connector on GenII's, well if that is the case, this would solve some intermittent problems folks were having on the GenI's.

Best Wishes on your fix and sorry I can not think of anything else to help you with.

 

[jeremybhm]

Update on this issue:

I replaced spark plugs and air filter, checked for vaccuum leaks(w/ starter fluid), and ran a bottle of fuel injector cleaner through it. I've ran two more tanks of super through it since then.

I think I can narrow it down to hot and humid days making it run worse. It seems to run smoothest on cool nights or early in the morning before it gets hot.

Does that trigger anything for anyone?

 

[radman]

Well, after watching the video, I would suggest putting oil in the motor. It doesn't sound very happy there. :blink:

 

[jeremybhm]

Well, after watching the video, I would suggest putting oil in the motor. It doesn't sound very happy there. :blink:

nice

As much as I can sometimes be mechanically retarded, it has plenty of oil and this has persisted across multiple oil changes. Also the bike has never used a drop of oil as far as I can tell between oil changes.

 

[Silent]

Are you running a Power Comander?

 

[charon76]

hot and humid days

You've tried the vaccuum check. Try a running plug wire check. mist the wires with water while running. Connect a test light to ground and run poin along wires checking for arcing. It's a longshot but possible.