BMW R1200R R1150R/T F800 K1200R R1100R/T R1250R RnineT Message Board

I just read this on a user page,and don't necessarily agree with it without any explanation provided. What are your experiences ?


"Valve adjustment requires rebalancing of the throttle bodies."

I replaced /upgraded my chain tensioner ,set my valves, and have had no issues.

Any help appreciated.

That's news to me. Maybe that's part of a 'regular' service interval?

You may not have to but, to really have the bike run at it's best it is recommended that the TB's be synched after valve adjustment. I think a lot of the bikes that did have a surge issue really did benefit from an accurate adjustment of both and are both part of the "regular" service interval as noted above.

Last summer I did a thorough maintenance including a valve adjustment and fresh spark plugs; the one thing I didn't do - since I didn't have the gizmo - was the throttle body balance. Before this work, I thought the bike ran well; after - it was a very subtle change - the bike ran really well. That continues till today. Therefore I didn't bother with the throttle body sync. At some point, I should buy/construct/borrow the necessary tool. But for now......if it ain't broke...you know the rest.

Buckster wrote:You may not have to but, to really have the bike run at it's best it is recommended that the TB's be synched after valve adjustment. I think a lot of the bikes that did have a surge issue really did benefit from an accurate adjustment of both and are both part of the "regular" service interval as noted above.

+1

Thanks,Photoguy,Buckster,Bogdan,and BadToTheBown.

Bogdan, I did just as you did,including the new plugs. It runs great, better even, and the cam chain noise being gone is nice.I haven't read that it's recommended after valve setting, but after thinking about it a few days, I think I will anyway.
Purged and refilled brakes and clutch last fall after I rebuilt the calipers and new pads on my '02 with 26000 miles.Put some aux lights on,too .
I think it's more about my having a good baseline for troubleshooting if I should have any problems. So far I haven't any issues since I've owned it,. :-)

Frequent, What tool do you intend to use to synchronize the throttle bodies ? BTW....What does Frequent refer to - sex, alcohol consumption or maybe daydreaming ?

Mr.Frequent wrote:I just read this on a user page,and don't necessarily agree with it without any explanation provided. What are your experiences ?


"Valve adjustment requires rebalancing of the throttle bodies."

I replaced /upgraded my chain tensioner ,set my valves, and have had no issues.

Any help appreciated.

It depends on the amount of adjustment. The only way to know if it’s needed is to connect a TB balance tool. Once connected to check it, correction only takes a few minutes.

Bogdan, frequent is a play on words .Frequent = freak went.
I've left the wild salad days of my 70's youth :-)

As for the adjustment, I'm five minutes away from a mechanic who has the equipment. Very reliable and noted bike mechanic.

No, I think throttle body balancing is not required after valve adjustments, but it probably will make your bike run smoother since if the valve lash on either cylinder was out of spec, then bringing it back to spec probably changed the air inspired by that cylinder, and if both cylinders are not inspiring the same volumes of air, then your engine is going to run like a Harley.

OTH, I would think a better statement would be,"You shouldn't balance your throttle bodies without first adjusting your valves".

What tool to use...

I balance them twice. I have a set of commercial metal differential gauges that I use but I then have a DIY manometer that uses water. Water is less than 10% as dense as mercury and provides the sensitivity for a much finer balance. There are different takes on how to balance but my preference is to:

• 1 - Clean and balance TB big brass screws at idle. Then leave them alone.
  2 - Make sure you have the proper amount of slack in the left side throttle cable.
  3 - Raise the revs to 2000 rpm and adjust the right side throttle body using only the throttle cable. The cable will go out of adjustment when you tighten the lock nut. Play with it until you get the TBs to balance AS YOU TIGHTEN the lock nut.

If you have done this and something weird happens and it all goes out of balance...Check that the metal cuff on the end of the cable is 100% seated in the collar on the throttle body. It can jump up and get caught on the edge. I have absolutely seen a BMW mechanic with the "Master Mechanic" certificate on the wall get caught out by this. If I didn't have a great deal of respect for his skill (and the fact he's getting old too) I would have laughed my lungs up. You know when it has happened but it has tripped me up many times.

Rs,

Sol

Thank you, Soliton.
Making the water manometer is an idea I've considered many times.It's reliable and affordable;cheap in fact for such a valuable tool.
I've also read to run it up to 4000 rpm and check at the higher rpm, too. Some note using a fan to prevent overheating. I may just do that.

Also read and noted your Monza cap idea.

I do it.

changing a valve gap will change the intake timing/pressure slightly. keep all things equal.

way overdue for both.