Surge scourge

[motojoe]

The surge scourge has finally infected my bike. 2004 R 24K miles on it. It started just before the 24K maint and I was really hoping that it was just a symptom of needing the normal maint.
So I did the following: Fluids, Valve adjust, spark plugs, TBS, reset motronic, plus I went ahead and changed the fuel filter, QDs this winter and installed new coils last month. I was wondering about checking the voltage of the tps? is that right? and would that have any influence in a surging bike and how would I do such a thing. Also when doing my TBS with my home made manometer, when I throttle up just from off idle I notice there is an immediate pull that then evens out at higher rpms. I am not even sure if that makes sense. I was thinking an air leak, but where do I look and how does one fix that? So any ideas or helpful links to things that have worked for others would be appreciated. By the way all the things I have been able to do on this bike came from knowlege attained on this site. Thanks to all who contribute.

[boxermania]

You have done all one can expect and assuming everything is in order the only other thing that comes tro mind is a leak at the o-ring between the TB's and the head. A minor leak there will cause the surging you have be experiencing.

Good luck

[keithbw]

Replacing those two flimsy little rings did wonders for mine.
I forgot who posted it, but if your idle screws are not fairly even in turns out from seated, it's a good indication that
at least one of the rings is leaking also.
Mine were 3/4 of a turn apart, now they are dead even, and the sycnching was a snap.
Surge is now barely detectable on my '02

[motojoe]

Thanks for your replys. I have been leaning twards the air leak idea as well. Is there a handy post perhaps with instructions on how to change those "flimsy O-rings"? I have found that info followed from this site is better written and comes with nice little hints so that your don't end up with bigger problems later. Also any specific O ring part numbers or sources for after market would also be helpful. Thanks again!

I also wanted to re inquire about instructions for checking voltage of tps. Thanks

[Xdot]

You have done all one can expect and assuming everything is in order the only other thing that comes tro mind is a leak at the o-ring between the TB's and the head. A minor leak there will cause the surging you have be experiencing.Good luck

I've had this cause problems in automobiles and other motorcycles as well. I know in a carbureted vehicle and induction leak will also cause hard starting. This may not be the case with EFI.

[jfslater98]

Also any specific O ring part numbers or sources for after market would also be helpful.

Yes, this thread held particular interest to me as well, although the problem is just about gone now (more on that later). While I'm here, which O-rings are we talking about?

Boxermania seems to be referring to #2 below


Is keithbw talking about the same thing? Or #11 below?


And Motojoe: not to sound like a wisea** but... make sure you've reconnected the air hoses back up to the throttle bodies after you've done the sync. From VERY recent (15 min ago) personal experience I can tell you that leaving the nipples unplugged will cause significant surging.

[keithbw]

I was referring to #11, far as I can tell, my '02 only has o-rings between the throttle bodies and the air inlet pipes that come out of the air-box,

Just loosened my tb's to check, no o-rings between the tb's and the head on my '02, just the rubber boot connector.
I did not unbolt the connector from the head however. If there are two more there, they are not affecting the operation of my RR at this time.....

I swapped the clamps some time back so I all I needed to get to the o-rings was a 2.5 mm allen head wrench.
After loosening the the hose clamps on each end of the air inlet pipe, just twist and shove the inlet pipe
into the air-box. Easy to swap the o-rings, just need to get the inlet pipe about an inch into the air-box.
If you want to check the connection to the head, it's just one more hose clamp. Loosen said clamp then work
the tb back and forth while you pull it away from the head. You do not have to loosen/remove anything else, just the
hose clamps.

I used dielectric grease on the o-rings and a McGuire's spray-on product on the boots connecting the tb to the head.
Don't know if it's good/bad in the long run, but the bike runs good, and it's much easier to disconnect those parts.
The boots are very pliable now, and as far as I can tell, well sealed.

[boxermania]

Air leaks that can potentially disrupt engine operation are the ones that occur downstream of the butterfly as they are not "measured" by the TPS. That being said, the source could be where the TB attaches to the intermediate piece or adapter and between the adapter and the head. (see the lower illustration two posts above, item #4)

The following post might help with both the understanding and adjustment of theTPS voltage.

viewtopic.php?f=2&t=20780&sid=b79b42309 ... 1d#p183261

[motojoe]

Thanks to all who contributed to my questions. I will let you know if the o-rings were the problem.

[jcridge]

No spraying and looking for RPM change to narrow cause?

[motojoe]

Also I wondered, could too small a spark plug gap cause surging issues?

[motojoe]

Spraying and checking for rmp changes? Please expand.

[jcridge]

Spraying and checking for rmp changes? Please expand.

Using a combustible spray such as a throttle body or carb cleaner, brake kleen,etc... quick sprays, one or two seconds using the straw that came with the can around the suspected areas. If you see or hear an RPM change, then you located the leak. This needs to be done carefully as you don't want to spray too much and get fumes up to the air intake, then you will get a false RPM change. If you direct the spray at the parts in question and wrap a towel close by at prevent the spray from getting where you don't want it and you will be fine. Mechanics have been doing this since the invention of the spray can. We used to use propane, but that get a little tricky now a days. I remember using freon (R12) as a leak detector way back when, problem with that is it created a deadly gas when combined with hydrocarbons.

John