first throttle body sync help

[Dr. Strangelove]

I am about to attempt my first TB sync; made my manometer; used red atf.
I will be doing my first valve adj beforehand.

I can find instructions for using the TwinMax, but cannot find instructions (for dummies) using the homebuilt device. 2004 R1150RA. ~~ 18000 miles

I see the Big Brass Screw; I know the engine should be at operating temp; there should be fans blowing on the cylinder heads; connect the manometer to the two TB nipples--should be a closed system. That's it for what I know...

will I be turning BOTH screws? Does the throttle linkage get loosened in the process? etc

any pointers to links describing this is appreciated...

Thanks

JOhn

[Byrdguy]

There should be a thread, the procedure is pretty much the same no matter what instrument you use. You make the adjustment to the TB cables. The brass screws are fine adjustments for the idle and shouldn't need much adjustment. (I think they should be pretty much the same # of turns out.)

[Byrdguy]

After some research, the above post is hardly complete, here is a good link to the procedure. http://www.ibmwr.org/r-tech/oilheads/R1 ... sync.shtml

[Boxer]

This little device from Marc Parnes will make the up-throttle part much easier.

http://www.marcparnes.com/BMW_Throttle_ ... g_Ring.htm

[MikeCam]

BBAS initial setting and adjustment.

1. Keeping count, fully seat the BBAS. Then back off 1.5 turns. Both sides even.

2. At warm idle, with manomometer attached, seek the 1050-1100rpm idle level while keeping both screws aligned equally in their relative position to 12 o'clock and each side of the manomometer equal.

3. When you are finished, both screws should be symetrically aligned and idle should be between 1050-1100 rpm.

[MikeCam]

BUT FIRST!!!!

Confirm your valves' adjustment.

[Dr. Strangelove]

BBAS initial setting and adjustment.

1. Keeping count, fully seat the BBAS. Then back off 1.5 turns. Both sides even.

2. At warm idle, with manomometer attached, seek the 1050-1100rpm idle level while keeping both screws aligned equally in their relative position to 12 o'clock and each side of the manomometer equal.

so I do not fool with the cable adjusters at all? I am using the BBAS to do this, ie adjust the idle to 1050-1100, and both screws are in the same alignment with respect to 12 o'clock?
Will adjusting to idle speed with the BBAS equalize the limbs of the manometer?

3. When you are finished, both screws should be symetrically aligned and idle should be between 1050-1100 rpm.

I just completed the valve adjustment; they were pretty close, but now they are better ( I hope)

Thanks for the responses and sorry for the newbie denseness
John

[MikeCam]

Quote: Will adjusting to idle speed with the BBAS equalize the limbs of the manometer?

There are three items to balance: the BBAS position relative to each other; the idle speed (1100rpm); and the manomometer fluid levels. That's the easy part of throttle body sync -- the idle adjustment.



After you have idle balanced, you still need to use the right side throttle cable adjuster and the manomometer to adjust running rpm (somewhere between 2500-4000 rpm).

With adjusted valves and balanced idle, you slowly increase throttle, watching the fluid levels change. Ideally, both levels will change exactly the same amount at the same rate as you throttle from 1100 rpm up to your selected level (2500 rpm or whatever). Ideals are hard to come by.

Note the difference in the levels at your selected rpm and adjust the right side cable tension to equalize. Follow the instructions at that web link...

You're doing fine.

[Dr. Strangelove]

Thanks, again for the patience
Let me see if I can put this in my own words and if my understanding is correct.

first ride enough to get the engine temp normal that it will maintain an idle speed of 1100 without the so-called "choke."

1 connect the manometer with the engine off
2 close down the bbas counting the turns to close ( I suspect this is in case all goes to hell, I can at least go back to (near) where I was in the beginning, right?)
3. now "open" the bbas 1.5 turns
3a. unlock the barrel adjuster on the right by loosening the 10mm locknut
4 start the engine
5. look at the manometer levels and turn each bbas to get a leveling of manometer levels

Question 1: Is there an idle adjustment as part of this procedure, or is that in the Motronic and not involved in this procedure? Currently my bike idles nicely ~~1100.
Question 2: how do you know which screw to turn? In other words, what do you see with the manometer levels that tells you to turn the R or the L bbas?

6. Get the manometer levels even at idle speed and then...
7. now get the manometer levels even at higher rpms--say 2500-3000 or at multiple levels, by using the barrel adjuster on the right side throttle cable.
8 go back to idle and the BBAS and re - adjust the levels at idle speed if necessary

9 go back up to speed to recheck the levels at higher rpms--adjust again with barrel adjuster if necessary.

10 go back to idle recheck

11. When balance is achieved at idle and at speed, lock down the locknut on the barrel adjuster and you're done.


Is that it? and many thanks again

[MikeCam]

Couple of things to be clear.

The BBAS is your idle adjustment. Both equal each other, manomometer levels equal, idle at 1100 - that's the whole adjustment.

Each time you adjust the hi rpm balance, you will need to tighten the lock nut to hold that particular cable tension... it is a very iterative process.

In all cases, the manomometer levels tell you which side is pulling more vacuum (higher level). Typically you adjust to bring the levels even by backing off one BBAS and adding the other BBAS evenly. It becomes clearer as you do it.

At hi rpm all adjustment is at the right side cable adjuster. Iterative and experience shows you the way....just use very small adjustments (1/8 turns) until you get the feel for it.

[ProductUser]

Let me add this bit of caution as you did not specify this in your posts.

Please be sure to have a couple of box fans, or similar, blowing on the cylindars. This will prevent your engine from overheating during the TB sync.

ProductUser.

[coyofmo]

Oh dear I just went through this (In addition to replacing those horrible fuel quickdisconnects..another thread). First and foremost, valves have to be right...I could get the next higher size feeler gauge in both my exhaust and intake when I opened the covers.
I used a twin max, and chased the needle around for a week before getting it right. First, I made the mistake of adjusting (Trying to adjust) the cables to achieve the low RPM balance...did not work. Fortunatly I did not try to adjust those stops that the bellcrank hits when at rest way in the back... thought about it..then thought better. Finally, I realized I needed to let the bellcrank rest on the stops, set the idle with the BBAS, THEN adjust the high speed balance by adjusting the cables, which I did at about 3800RPM...don't know what the heck I was thinking..trying to use the force or something.
Also, the twin max cables did not have a really good seal on the vacume probes coming off the bike..I tried using clamps on them but they kept falling off and I still don't think they were sealing well...I finally bought new hoses that fit and connectors..making sure to have equal lengths coming off the twinmax. Finally, I found at the highest sensitivity I could not get the twinmax to center with the bike idling...I backed it off just a tad and it was much more easy...then went to max sensitivity for the final precise adjustments at idle and high.
Hope this helps someone to not make the same mistakes I did..all is well now. Coy

[iowabeakster]

Maybe this helps.

You are going to "synch" twice.

1. First the idle "Synch". Use the BBS Screws to do that.
idle done... forget about the screws

2. On throttle "Synch". Say 3500 RPM. Similar to the idle, but use the cable adjustments to balance the difference (ON THROTTLE). You just pick one side (usually right) and match it to the other. It will be a somewhat tedious task. Small adjustments, while tightening down the lock nut. The better you do this, the smoother the ride. Patience will win. This is one of those Zen things.

Read that instruction for the "TWIN MAX" it really gives great info. If you don't absolutely understand it yet, have a drink, read it again. Now with your homemade device, you will not use the "Twin Max" itself. Just remember that your device is doing the same thing as the twin max. Measuring the vacuum difference between the cylinders.

http://www.advrider.com/Wisdom/TBS4Dv1.0.pdf

[awagnon]

The above posts are correct. I would stress that the throttle body sync is actually two synchronizations.

1. First you balance the throttle bodies at idle with the BBS's. Do not try to balance with the throttle cable or you will end up lifting one side (usually the right) off the idle stop. If you need to increase the idle speed, adjust both BBS's equally.

2. Second, balance again with the engine around 3500 RPM. This time balance with the right cable adjuster. Afterwards, turn off the engine and make sure you still can hear the right throttle valve seating on the idle stop. Sometimes you adjust the right cable so much it can lift the right side off the stop.

Some real anal types will strap the TwinMax to the bike and balance the throttle bodies while riding. Actually they stop and make adjustments and then ride some more. Probably over kill.

[Dr. Strangelove]

OK, I think I have it.

I will try it tomorrow am and ost my results.

thanks to all

John

[iowabeakster]

Beat ya Al!

[awagnon]

Beat ya Al!

Yep, you sure did. I'm a slow typer. Amazing how similar our posts were. Must be mental telepathy.

[awagnon]

I have to keep my dog, a boxer named Paisley, balanced. Sometimes one ear will flop up and the other flop down. When that happens she surges terribly.

[CycleRob]

One important caution. Do NOT overtighten the cable barrel's locknuts. The barrels are made of soft materials (brass?) and if you snap it in the threads, it is an expen$ive labor cost for the necessary throttle cable R&R.

To clear up another mystery, the BBAS number of turns out is totally dependent on both of the tamper-proof blue painted throttle stop screws being set perfectly. It is not vital that both BBAS be the same. They exist as a user-safe and convenient fine tuning mechanism for the no touchy blue painted throttle stop screws. Because the calibrated TPS idle voltage setting and precise closed throttle minimum airflow settings will be GONE when the blue painted throttle stop screws are turned, they should NOT be adjusted !!!. If they are adjusted, (Oh NO!!) your bike will run lousy until an informed mechanic, like those at BMW dealers, carefully sets them right again. Even when new and factory set, it's not likely the BBAS will be exactly equally set. After many miles of normal wear and thousands of times at hitting the idle stops (TapTapTapTapTapTapTapTapTapTapTapTapTapTap!), they will most likely be different, as much as a full turn different, when the idle is perfectly synched. If there is a large BBAS difference in turns from seated between the 2 BBAS, it indicates a TPS re-adjustment, high mileage normal wear, a gummed up air bleed passageway or tampering with the blue painted stop screws. Either way, if the BBAS are able to obtain a perfect synch, it's as good as it gets until/if the discrepancy will be fixed (if desired).

I hope I didn't confuse you too much, but that is exactly what the BBAS and blue painted throttle stop screws are all about.

On making the adjustments with the oil manometer - - - If the settings are wacked out (far from good), the oil will be sucked right out of one side of the tubing as soon as you start the engine. Pinch the tubing shut on one side between your fingers as you start the engine , then slowly release it to see what happens. Be ready to pinch it again (and hold it) to prevent it from going out over the top. Let the engine idle while you next do the following. The higher oil column indicates higher vacuum and smaller throttle or BBAS opening. To rectify, back OUT (unscrew) the BBAS on the high oil side a quarter turn -and- screw IN the opposite BBAS a quarter turn to work towards correcting the idle setting so oil isn't sucked out. If you are using small diameter tubing throughout that fits snuggly on the TB spigots, it will be too small for ATF and be VERY sluggish to respond. I know because that happened to me. I improved the response speed by flushing it out and filling it with WD-40. The cure is larger tubing and lighter oil or tinted water.

If the on-throttle setting sucks oil out over the top, shut the throttle and raise the throttle cable (unscrew) a quarter turn for the high oil level side -or- if the minimum cable freeplay goes away when you do that, go to the other TB and screw in the low oil side cable's knurled adjuster a quarter turn and lightly snug up the locknut. Try the throttle again and repeat, using progressively smaller increments, until the oil levels are even.

From there it is just repeat those above steps, by intuitive, minute increments, until idle and on-throttle settings are within a sixteenth inch. The next time you do a TB synch, you'll understand which does what and how much - - - a lot better. Oh yes - - - - read and remember my 1st sentence above.

[mad1150]

Thx awagnon & iowabeakster,

I have been having issues with the Sync instructions I downloaded too. It seem they overcomplicated them. 22 pages of precise and detailed info that confuses the $#!* out of me every time I read it.

Your simple explanation of this 2-step process clears it all up. Amazing!


and Cyclerob - thx for your added warnings and insight too!