GEN2 stumble during takeoff

[kt4vq]

I posted this question on Facebook and forgot here is where the most knowledgeable folks hang out. Sigh....

I have an 07 (my 2nd FJR, 1st one was 05) that I bought two years ago that had 4k miles. It now has 26k +- miles and until now has run like a champ except for an occasional slight stumble at idle hot or cold.

When I first got this bike I did all of the fluids, TBS, battery, and plugs. Cleaned air filter, etc.... (Upgraded suspension and added electronic cruise control which has nothing to do with the stumble.) I also removed the PAIR.

Recently, I developed an obvious consistent stumble when taking off hot or cold. It is consistent between 1.5 and 2k rpm but only under load. After 2k it is the typical FJR. No load throttle is fine, no stumble when working the throttle.

I noted the battery was a bit weak so I replaced the battery. Still have the same issue.

I did a TBS. It was just about perfect. #4 needed a slight adjustment.

I did notice on the most recent TBS that the occasional slight stumble appeared to be on #4 but did see it once on #1 as indicated on the vacuum gages by a dip. Being that this is the same coil pack I am beginning to wonder about the health of that coil.

I have carefully inspected the vacuum lines.

Based on Lumberg's post on his issue with his 14 made me run a diagnostics.

I ran a diagnostic test on

01: Throttle position sensor (throttle angle)
30: Cylinders-#1/#4 ignition coil

31: Cylinders-#2/#3 ignition coil

36: Injector #1
37: Injector #2

38: Injector #3

39: Injector #4

48: Air induction system solenoid

No error codes were noted.

Since mine is not a GEN3 and the suggestions you folks made to Lumberg do not exactly match up with a GEN2 I felt like a question to the group was in order. I searched GEN2 stumbles on the site but none match up with my concern.

I don't think the diagnostic test can measure the continuity/resistance of the plug wires so my next "guess" is to check/replace plugs and check plug wire continuity (I hope to but I think the plug wire is molded into the coils??)

Do any of you have other areas to investigate?

 

[RossKean]

I don't think the wire can be removed from the coil but it can from the plug cap. It more-or-less unscrews - the cap has sort of a threaded spike that screws into the wire. Sometimes, it helps to unscrew, trim a 1/4" or so and screw it back. More would be better but there is not much excess wire length.

Check/replace spark plugs.
I wouldn't try to check wire continuity. This is high voltage stuff and whatever you measured would be meaningless anyway.

Injectors - dirty or bad. You can get them cleaned and tested for fairly reasonable cost. If your issue seems to be confined to one cylinder, you can try swapping injectors.

Where is your idle set? 1100 or even 1150 might help...

 

[kt4vq]

Hey Ross the idle is at what looks like 1150 - 1200. Hard to tell precisely though. Most likely closer to 1200 - 1250.

 

[BigOgre]

Might this be of any help? I've never dealt with it but have read a few who've cleaned and/or replaced the resistors under the cap.

https://www.fjrowners.com/threads/2...ing-idle-low-rpm-acceleration-misfire.155071/

 

[RossKean]

Hey Ross the idle is at what looks like 1150 - 1200. Hard to tell precisely though. Most likely closer to 1200 - 1250.

Higher than necessary but shouldn't cause a stumble. I run my (2011) at around 1100 or a touch higher (warm idle).

Might this be of any help? I've never dealt with it but have read a few who've cleaned and/or replaced the resistors under the cap.

https://www.fjrowners.com/threads/2...ing-idle-low-rpm-acceleration-misfire.155071/

I read your attached thread. I have heard of an improvement after snipping a quarter inch off the lead to the plug cap but never anything about the resistors in the caps being a problem. I guess it wouldn't hurt to have a look if you are dressing up the ends of the plug wires anyway.

I think maybe I would change the plugs, especially of they are old, and run a few tanks of gas through with some fuel injector cleaner before doing much else. I like Yamaha Ring Free. Techron is decent stuff. Not a big fan of Seafoam, although some people like it.

 

[kt4vq]

I agree. I ordered plugs which should be here Thursday. I will check the coils and plug caps per page 8-226 in the service manual. I have dumped a lot of fuel cleaner through this bike of the last few years. Every third tank or so gets a bit of cleaner and definitely at oil change.

 

[torch]

Try bumping the CO values +5 across the board and see if that has an effect.

When my 06 was my brother's 06 he had a similar stumble which was cured by the above. I have since had the Ivan's flash, which is another option if playing with the CO settings seems to help.

 

[Mihalis fjr]

Sounds to me like a defective TPS.In the most cases of defective TPS the diagnostic test didn't find that it was defective..

 

[Paul Land (Balrockus)]

What is your battery voltage when running?

 

[Diablo1]

Your spark plugs have 22,000 miles on them, change them before you overthink this.

 

[redneckj]

Sounds to me like a defective TPS.In the most cases of defective TPS the diagnostic test didn't find that it was defective..

This

 

[RossKean]

This

Both Gen I and early GenIII seem to suffer more from TPS issues compared to Gen II. Still, it is a good possibility but hard to test without replacement. I would do plugs and other stuff first.

 

[ALFJR]

I seem to recall that Yamaha issued a TPS recall for Gen II bikes quite a while ago. Not sure Yamaha would still perform such a recall if your bike was missed. However like others have said, I would certainly suspect the TPS in your situation. Just my two cents.

 

[RossKean]

I seem to recall that Yamaha issued a TPS recall for Gen II bikes quite a while ago. Not sure Yamaha would still perform such a recall if your bike was missed. However like others have said, I would certainly suspect the TPS in your situation. Just my two cents.

Nothing that I remember.
S4 spider for early Gen II, instrument cluster on very early '06, ignition switch, ECU on some '06/'07 (altitude sickness), front brake switch.
These are the only ones that come to mind.

Edit: Had to look it up. Gen I had a TPS safety recall and/or a TPS "Factory Modification" - I assume the latter is voluntary but directed by the factory for dealers to make the replacements.
No TPS recalls for Gen II or Gen III+.

 

[ALFJR]

Nothing that I remember.
S4 spider for early Gen II, instrument cluster on very early '06, ignition switch, ECU on some '06/'07 (altitude sickness), front brake switch.
These are the only ones that come to mind.

Edit: Had to look it up. Gen I had a TPS safety recall and/or a TPS "Factory Modification" - I assume the latter is voluntary but directed by the factory for dealers to make the replacements.
No TPS recalls for Gen II or Gen III+.

I found the work order/receipt for the TPS replacement performed in 2008 on my 2005 FJR. It had labor charges as Recall and parts charges listed as Warranty. The dealer also placed a punch mark above the VIN plate to indicate the recall was complete. I had typed Gen II in my above post instead of Gen I.

Either way, given the above stumble symptoms, I would consider a TPS replacement.

 

[RossKean]

I found the work order/receipt for the TPS replacement performed in 2008 on my 2005 FJR. It had labor charges as Recall and parts charges listed as Warranty. The dealer also placed a punch mark above the VIN plate to indicate the recall was complete. I had typed Gen II in my above post instead of Gen I.

Either way, given the above stumble symptoms, I would consider a TPS replacement.

Understood, but the OP has a 2007, Gen II - the recall only applied to Gen I. Still, I don't disagree that the TPS is a possibility but replacing it is probably not the first thing I would do - especially given the $200 cost.

 

[kt4vq]

Okay The battery is new (one week). I replaced the plugs today. I checked the plug cap resistance.

What is your battery voltage when running?

new battery (one week old).

 

[kt4vq]

Just to update. I replaced plugs, checked plug caps, went for test ride.

Still has stumbles at 1.5-2k and just after 2k it runs perfectly.

I failed to provide one other symptom, for the last 20k miles at warm or cold idle the bike would (miss a lick) once every minute or so. It was not consistent just once in a while. Since plug change that is not happening. Just the stumble on take off. No load throttle twist there is no stumble, just under load does it stumble.

 

[RossKean]

Do a search for Barbarian Jumper Mod and try adjusting the CO settings as @torch suggested, above. Does the wire look OK where the "spike" from the plug cap screws into it?

See if anyone local does fuel injector test/clean/service. If not, there are places you can send them.
TPS is still a possibility.

 

[kt4vq]

What is your battery voltage when running?

Brand new battery one week ago.