TBS Issue

[Richouse]

I have synced the Throttle Body's on my old FJR and have synced them once at the 600mi check on my new FJR. I have no question on how to do it, my question is how to set the #3 cylinder. All the directions have you syncing to the #3 but don't say (that I can find) how to set that one. I have the home made TBS sync tool listed HERE so I can't set it to a specific setting.

Reason I'm asking is after I bought it and rode it a while I noticed a 200 to 300 rpm pulse at idle, only when warmed up though. I didn't worry much since I would sync the TB at the 600mi. check. Well after I synced them it is still pulsing. Idle is set 1100rpm and it pulses up to about 1400rpm. I can just barley crack open the throttle (off idle) and make it stop.

I just figure that the #3 is not set right and when synced to it they are all not right.

Bike is a 2010 model with approx 1400 miles, The thought of the TPS is not right or bad has crossed my mind but being new I figure it just needs to be synced right?

So how do I set #3???

Thanks,

 

[seventyss]

Cylinder 3 is not adjustable, set cylinders 1,2 and 4 so they are in sync with cylinder 3.

 

[Fred W]

Cylinder 3 is not adjustable, set cylinders 1,2 and 4 so they are in sync with cylinder 3.

It most certainly is. Has the exact same air screw as the other three.

All of this "syncing to #3" is complete BS. There is no real reason to use #3 as the gold standard.

The objective of syncing the throttle bodies is just to get them all the same, at the correct idle speed, and with whatever vacuum value they have.

You have no control over what that will be. You can't adjust the #3 vacuum without effecting the other three and the idle speed.

You may want to read through the Really, Definitely, Completely UnAuthorized TBS thread here. Lot's of good food for the grey matter. That procedure seems to come up with the best results of any found to date.

FWIW - Your 300 rpm surges at idle are probably not at all related to the TBS. More likely to be a slight vacuum leak or lean condition.

 

[03HiYoSilver]

Rich,

Easily Bottom out the #3 Screw (Clockwise) and then Back it out about 1- 1 1/2 Turns to establish a Baseline.

Then try the 3-4k RPM balancing if you do not want to do the Advanced method.

If it still pulses, then like Fred says...there's a Air Leak or something.

 

[RaYzerman19]

I have learned that if you do use #3 as a baseline, it should be at least one full turn out. Less than that can affect your ability to set a proper idle speed. But, you don't have to use #3, you can use any one of them, just set it first and sync all the others to it. Use the procedure Fred mentions.

 

[Richouse]

Wow, that was some fast responses.. gotta love this forum... anyway, I guess it could be a vac leak. I installed a cruise control a while back but I think it was doing that before I installed it. I'll go over the lines again when I get the tank off.

A lean condition very well might be it, if that will cause surging. I pulled a spark plug a week or so ago and noticed that the tip was paper white (they should be the color of a brown paper bag). I did the Barbarian jumper mod and noticed all the cylinders were set to 0. I bumped them up to 7. I'll pull a plug again and check the color and might bump them up some more...

I do have a set of 2 bro's. slip on's. but I think the conscious here is that they won't cause a lean condition.

If I understand it right, making the mixture richer via the Barbarian Jumper mod only effects it at idle????

Thanks,

 

[Niehart]

My 2010 does the same thing and like you, I did a TBS.

Still have the same condition, it sounds & lopes like a cammed up big block engine.

 

[Fred W]

Make sure the idle is high enough. One of the locals w/ a 2010 was having stalling issues (as soon as he gave it any gas it would stall) and a rough idle.

We bumped his idle up to ~1150 and it's all better now.

I'm running my 1st gen idle up at ~1200 rpm as I think it helps some with the off to on throttle transition.

 

[Niehart]

Fred, I was at 1100, bumped it to 1200 and it did help. Still there but not as bad. Thanks.

Also printed out your un-authorized TBS and will try that.