Throttle body sync/balanced cylinders

[steve'o']

Ok....so I did a throttle body sync with a Motion Pro tool, with a friends help, who btw has much more knowledge than I do when it comes to mechanical things.

So I started by going to the forum and printing off the directions on how to do the sync.

I brought the directions out to my friend and he said "what about balancing the cylinders"?

I said I have no idea what you mean, the TBS directions are right here.

He said the cylinders should be balanced out. At this point I trusted that he knew more than I, so I tagged along.

He took a baseline reading from #3 cylinder and then proceeded to turn a set screw that brought up #4 to the same reading as #3.

He then did the same with #1 & #2 cylinders, balancing those two together.

He then said there had to be a third screw to balance #1 & #2 with #3 & #4.

We finally found that screw and balanced #1 & #2 with #3 & #4.

Theses screws are not the fuel/air mixture screws on each cylinder, they are larger phillips head screws.

After we balanced the two banks we then tweaked the fuel/air screws from 0 out to 2 1/2 turns, and did a test ride.....Well I have only one thing to say......Holy Crap!!!!

It's like having a new bike. The power is unbelievable. The bike pulls like a freight train right to 9000 rpm and is so smooth.

Previous to this I had some bar vibration, but now it's next to nothing, and before my tach needle would jump at 1100 rpm idle and the bike seemed to surge, now it's as steady as a rock at 1100 rpm.

Is this blind luck, or has anyone performed this on their bike, and is this something that can be done another way? ie: computer?

 

[Fred W]

Your friend just performed the Really Definitely Completely UnAuthorized TBS. You can read the procedure here:

RDCUA TBS Procedure

 

[steve'o']

So is that a good thing or a bad thing? I know the bike works better and is smoother.

 

[mcatrophy]

So is that a good thing or a bad thing? I know the bike works better and is smoother.

I think you've just answered your own question.

 

[Fred W]

It has been a very good thing for a whole lot of folks who have adopted my method of sync.

I may have identified a weakness in the process on my own bike recently, and that may be that when the throttle plates get really grungy, as they are wont to, the adjustment of the throttle butterflies may not be optimum due to the grunge. My last RDCUA TBS resulted in better vacuum balance when done, but more vibration at upper rpms. I am going to revisit the procedure soon as I get a chance and see if there is a better way to skin that cat, but my engine has 80k miles on it and the throttle plates have never been cleaned. For those with clean throttle plates the procedure works very well.

 

[SoCalFJR1300]

I was told by a fellow FJR rider that that is the ONLY way to do a proper TBS.

 

[scootman286]

Thank you Fred, just did your procedure and that worked great. I will get it out for a ride but it seems a lot smoother.

I was not aware I could run the air screws all the way in and do any tuning at all, great bit of info there. I am sure it work on the Warrior as well, thanks again.

 

[bluesdog]

I did the RDCUA TBS last year, and was pleased with the results. I especially noticed much improved smoothness at slow speed/low gear -- as when inching along in slow traffic.

Over the winter I installed some Staintunes & a PC-V, but never bothered looking at the TBS until just yesterday. I typically revisit the TBS following an oil/filter change, so had ridden more than 5000Km since installing the cans.

I was pleased to discover that it was still almost spot on. I made very small adjustments to #2 and #3; maybe 1 or two degrees turn on the air screws.

Note I did the PAIR/Wynpro thing last year, which I think has some impact on keeping the butterflies clean.

IMO, the RDCUA TBS is far superior to the standard method.

 

[scootman286]

Okay, that was awesome. Took it for a ride today and the smoothness is AMAZING. Throttle response seems likes it is new. I rode without gloves and felt the smoothness at 4k, used to be quite a bit of vibration there.

BY FAR, THE BEST TB SYNC I HAVE DONE...THANKS FRED

 

[Donal]

Just wanted to add my 2p worth. I carried out the RDCUA TBS Procedure a couple of days ago. Took it out today and what a difference!

It's amazing how you get used to increasing vibration if it happens gradually. The only thing I had become aware of was 'tiredness' in my right hand to the point where I would need to focus occasionally on relaxing that hand.

Now there is almost zero vibration particularly above 4K RPM. Interestingly it seems even smoother on deceleration...................

So a huge thanks Fred, this is without doubt the single best, most effective thing I have done on this bike.............

 

[Auron]

I was going to sell my FJR if I couldn't do something about the vibration, it was the buzziest bike I've owned of 20 at 75mph. Now it's the smoothest bike I've owned.

For anyone that hasn't done it that thinks their FJR is smooth makes me laugh.

 

[FJRMGM]

I was going to sell my FJR if I couldn't do something about the vibration, it was the buzziest bike I've owned of 20 at 75mph. Now it's the smoothest bike I've owned.
For anyone that hasn't done it that thinks their FJR is smooth makes me laugh.

Interesting - just last night as I was running at 75 mph I was thinking how smooth my FJR runs at that speed!

but I am still going to try this adjustment in the next couple of weeks to see if it makes a difference.

 

[steve'o']

If it needs any adjustment, I'm sure you'll notice a difference. I will say I wish I would have done this 2-3 yrs ago. Didn't know what I was missing.

 

[FJRMGM]

Well I did the Really Definitely Completely UnAuthorized TBS on my '05 FJR with 96k miles before heading to EOM and I have to say it does feel smoother at 70 mph so it was worth the effort for sure.

So thanks.

 

[FJRTom]

OK, I am probably a pathetic loser who's blind, but...

This weekend I was doing a bunch of maintenance on my 2013 FJR -- after doing a combination Three Flags Classic and USA Four Corners Tour (13,628 miles in 23 riding days) -- and while changing plugs and removing the pulse air system I decided to do a TBS. Unlike my past 2005 and 2008 FJRs, I don't see any air adjustment screws! Do the '13s still have them? Are they relocated? Will the RDCUTBS work?

Thanks for the help.

 

[steve'o']

Hmmm...not sure FJRTom, but I'm sure one of the wiser more experienced ones on the forum can answer your question.

 

[FJRTom]

Bump.

I am still waiting for some input / help, Gang. See the question two posts above. Any insight will be greatly appreciated!

 

[Fred W]

OK, I am probably a pathetic loser who's blind, but...
This weekend I was doing a bunch of maintenance on my 2013 FJR -- after doing a combination Three Flags Classic and USA Four Corners Tour (13,628 miles in 23 riding days) -- and while changing plugs and removing the pulse air system I decided to do a TBS. Unlike my past 2005 and 2008 FJRs, I don't see any air adjustment screws! Do the '13s still have them? Are they relocated? Will the RDCUTBS work?

Thanks for the help.

Bump.
I am still waiting for some input / help, Gang. See the question two posts above. Any insight will be greatly appreciated!

You may be waiting for quite a while.

You are in uncharted territory as not many folks have a 2013 to play with.

I can't answer your question and I am the originator of the RDCUA TBS.

 

[08FJR4ME]

If you look at some of the OEM parts fiche from 2010 to 2013 you may be able to compare them to see if they have the same part numbers. If they do then I would ASUME your O.K.

Dave