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1997 R850R Solving Vibration and Cat Code Plug Change
- Thread starter senseamidmadness
- Start date
senseamidmadness
Neglected Bike Adopter
Since you are recoiling in collective horror, I would like to emphasize that the original repair was a temporary solution just to get the bike running for a while, with known-improper materials. I promise my solder joints look much better than the outside would suggest. My soldering experience is far more in the area of printed circuit boards and I'm still learning proper finishing work on automotive wiring harnesses.
This is the improved repair with the correct PTFE-jacketed wire and heat shrink tubing. I just reinstalled it and the bike started up fine. I made one mistake during the reassembly and am not 100 percent sure that the waterproofing of this repair is perfect, but it is certainly much better than it was.
Unrelated, but when I went to put the sensor back in a squirrel had stuffed a half-eaten piece of pepperoni pizza between the Telelever and the engine case! Wish I had gotten a picture of that.
This is the improved repair with the correct PTFE-jacketed wire and heat shrink tubing. I just reinstalled it and the bike started up fine. I made one mistake during the reassembly and am not 100 percent sure that the waterproofing of this repair is perfect, but it is certainly much better than it was.
Unrelated, but when I went to put the sensor back in a squirrel had stuffed a half-eaten piece of pepperoni pizza between the Telelever and the engine case! Wish I had gotten a picture of that.
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Squirrels can be problematic- this shot, see the orange glow of the fire, was from the this morning. For the third time this year, a squirrel wanted to see if it was faster than the speed of light. 4400v leaves them wishing they had skipped trying-
OM
OM
senseamidmadness
Neglected Bike Adopter
I think by tossing the pizza just a few feet away instead of throwing it in the trash I may have evaded the squirrel's wrath.
Helps that I fled the scene before it showed up.
On a non-squirrel related topic, the new spark plug wires and Hall sensor repair didn't do anything for my bike's vibration. It was okay when it first started up, but it's back to as buzzy as ever. I think the Motronic started out richer and then leaned out again.
At this point I'm thinking it could be a wonky O2 sensor making the bike run just a bit too lean, or maybe my particular bike is just this way. When I buy an AF-XIED it should smooth it out, and just to be safe I'm going to buy a new oxygen sensor at the same time.
I suppose I could still check diligently for vacuum leaks on either intake side but I'm not sure I'll find anything, since I replaced all the rubber parts. I'll spray a bit of something volatile near the intakes while it's running and see what happens.
Helps that I fled the scene before it showed up.
On a non-squirrel related topic, the new spark plug wires and Hall sensor repair didn't do anything for my bike's vibration. It was okay when it first started up, but it's back to as buzzy as ever. I think the Motronic started out richer and then leaned out again.
At this point I'm thinking it could be a wonky O2 sensor making the bike run just a bit too lean, or maybe my particular bike is just this way. When I buy an AF-XIED it should smooth it out, and just to be safe I'm going to buy a new oxygen sensor at the same time.
I suppose I could still check diligently for vacuum leaks on either intake side but I'm not sure I'll find anything, since I replaced all the rubber parts. I'll spray a bit of something volatile near the intakes while it's running and see what happens.
pglaves
#13338
OK Back in my Bench Wrenching column I wrote about imbalance and vibration and made a big distinction between "combustion imbalance" and "mechanical imbalance.:
At this, point having followed this thread, I am convinced you have a mechanical imbalance: probably an improperly installed clutch pack.
Combustion imbalance will ONLY cause a vibration when one cylinder is affected and the other is not. So the Motronic, and any other fuel related cause other than a bad injector ought to cause the problem in both; not just one cylinder.
Valves? Throttle bodies? Plugs? Wires? Coils?
If all OK it is not combustion related. So is it a mechanical imbalance?? I have my suspicions!
senseamidmadness
Neglected Bike Adopter
Well the trouble is that when I pulled my cat code plug entirely, and the fueling actually went open-loop, the engine was significantly smoothed out. Exactly as people describe what it's supposed to be like -- it was so smooth I could no longer tell what RPM the engine was at by feel and had to tell by sound.
If I had a clutch pack imbalance, I still would've been able to feel vibration at that point, right?
If I had a clutch pack imbalance, I still would've been able to feel vibration at that point, right?
senseamidmadness
Neglected Bike Adopter
BIG UPDATE: I now have a prime suspect.
Sprayed starting fluid all over the intake side -- and got a slight uptick in idle when spraying it right at the Big Brass Screw on the right throttle body. Hmm.
Pulled the screw out, and the O-ring on it was mangled. I can't entirely remember if I replaced them when I cleaned out the throttle bodies or not. Checked the left one and it, too, has seen better days, plus the screws were almost a full turn off from each other! I had set the idle sync perfectly on my Carbtune but didn't notice how differently I had to set the screws to do it. D'oh!
Regardless, I now strongly suspect that my throttle body sync is totally off because I synchronized with an active vacuum leak!
Where do I order new O-rings and possibly new Big Brass Screws?
Edit: Here's some comedy for you folks. I slapped a new pair of close-sized Imperial NBR O-rings onto the brass screws just to get me home and seal off the vacuum leak, and the vibration got better at idle but worse while actually riding! How's that for proof of a flawed throttle sync?
Sprayed starting fluid all over the intake side -- and got a slight uptick in idle when spraying it right at the Big Brass Screw on the right throttle body. Hmm.
Pulled the screw out, and the O-ring on it was mangled. I can't entirely remember if I replaced them when I cleaned out the throttle bodies or not. Checked the left one and it, too, has seen better days, plus the screws were almost a full turn off from each other! I had set the idle sync perfectly on my Carbtune but didn't notice how differently I had to set the screws to do it. D'oh!
Regardless, I now strongly suspect that my throttle body sync is totally off because I synchronized with an active vacuum leak!
Where do I order new O-rings and possibly new Big Brass Screws?
Edit: Here's some comedy for you folks. I slapped a new pair of close-sized Imperial NBR O-rings onto the brass screws just to get me home and seal off the vacuum leak, and the vibration got better at idle but worse while actually riding! How's that for proof of a flawed throttle sync?
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pglaves
#13338
Yes.
Now, as to that vacuum leak at the BBS. I think it now makes some sense. With the leak you had one cylinder too lean and the other presumably OK. Pulling the cat code plug enriched the mixture in both cylinders. That then gave you one cylinder OK but the other too rich. But the engine can tolerate a mixture that is a little rich better than one a little lean.
So seal things up and synch the TBs and let us know.
senseamidmadness
Neglected Bike Adopter
The squirrel?
Yes, I've been called a smartass before.
I did refer to the O-rings as "chewed up" in my maintenance log, so...
Maybe I need to leave another piece of pizza outside as a peace offering, to dispel the Curse of the Squirrel!
A new pair of Big Brass Screws have been ordered and I will update after the sync.
senseamidmadness
Neglected Bike Adopter
Did a quick-and-dirty parking-lot throttle body sync today with the Carbtune and the existing BBS/O-rings, and I'm happy to report it did make a difference!
What used to be a vibration that got uniformly worse with higher RPM's now comes and goes as I vary speeds and revs, and there are even a couple "sweet spots" in the rpm range. The bike is shaking less at idle, and the overall intensity of the buzzing while riding above a few thousand rpm has roughly been cut in half. It might be even better once I replace both screws and rings with new OEM parts and do a more careful sync with a tachometer installed.
There are spots in the rev range and at some engine loads where the footpegs vibrate more, some where the handlebars vibrate more, and some where both smooth out, and there's just a tickle of vibration at idle. I believe this is referred to as "character".
As of right now it's a whole lot better and I'm going to keep riding it like this until I hit 36k miles within the next few weeks. At that point I'm going to pull the battery box off to replace my battery cables, and do another more careful sync.
I still find myself thinking about how incredibly smooth it felt when running open-loop, so at some point I'll probably still buy an enrichment device, but as of now it's a smoother bike than any previous one I've owned. That's exactly what I was hoping for.
Edit after a 20-mile highway ride: Riding on the interstate is still buzzy, but definitely better than before. I got my tach installed and at typical interstate speeds just above 60MPH the engine is turning about 4,000 RPM in 5th gear. The vibration is more pronounced in the handlebars than the footpegs at that speed so I might still get some HVMP bar ends before I go any longer distances.
What used to be a vibration that got uniformly worse with higher RPM's now comes and goes as I vary speeds and revs, and there are even a couple "sweet spots" in the rpm range. The bike is shaking less at idle, and the overall intensity of the buzzing while riding above a few thousand rpm has roughly been cut in half. It might be even better once I replace both screws and rings with new OEM parts and do a more careful sync with a tachometer installed.
There are spots in the rev range and at some engine loads where the footpegs vibrate more, some where the handlebars vibrate more, and some where both smooth out, and there's just a tickle of vibration at idle. I believe this is referred to as "character".
As of right now it's a whole lot better and I'm going to keep riding it like this until I hit 36k miles within the next few weeks. At that point I'm going to pull the battery box off to replace my battery cables, and do another more careful sync.
I still find myself thinking about how incredibly smooth it felt when running open-loop, so at some point I'll probably still buy an enrichment device, but as of now it's a smoother bike than any previous one I've owned. That's exactly what I was hoping for.
Edit after a 20-mile highway ride: Riding on the interstate is still buzzy, but definitely better than before. I got my tach installed and at typical interstate speeds just above 60MPH the engine is turning about 4,000 RPM in 5th gear. The vibration is more pronounced in the handlebars than the footpegs at that speed so I might still get some HVMP bar ends before I go any longer distances.
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senseamidmadness
Neglected Bike Adopter
Minor update: Bike's still going strong, and today I rode over 20 miles on absolutely soaked roads with zero issues or hesitation. So my improved Hall Sensor repair seems to be totally waterproof. The vibration in the bars and pegs at 60mph is still the same, just a tickle of buzzing.
m_stock10506
Well-known member
You know that almost all of the “older” R bikes, including the Airheads, have a natural buzz at some of the rpm range. The big pistons, going in and out at the same time, with no offset balancer. It’s not like riding a triple or four cylinder motor. You should find a friend with another oilhead and swap rides. Compare the experience. You might be chasing ghosts.
senseamidmadness
Neglected Bike Adopter
Oh, I should've mentioned m_stock that the buzzing I've been feeling today seems exactly like what you're describing. It's a lot better than it was and is no longer terribly annoying. Feels like the engine humming to itself.
I don't expect that it'll get much smoother than this unless I buy an enrichment device. It's tolerable as it is. It may still get a smidge better when I put the new pair of Big Brass Screws in and do an even more careful throttle body sync.
It's currently worlds better than it first was before I did all my fixes.
Hilariously enough, my last bike was an inline four, a 2002 Kawasaki Concours 1000, and that was the most vibrational bike I've ever ridden...would make my hands go numb in minutes at high rpm's.
I don't expect that it'll get much smoother than this unless I buy an enrichment device. It's tolerable as it is. It may still get a smidge better when I put the new pair of Big Brass Screws in and do an even more careful throttle body sync.
It's currently worlds better than it first was before I did all my fixes.
Hilariously enough, my last bike was an inline four, a 2002 Kawasaki Concours 1000, and that was the most vibrational bike I've ever ridden...would make my hands go numb in minutes at high rpm's.
senseamidmadness
Neglected Bike Adopter
Minor update to this for future reference:
I've been riding my R1100RT pretty much exclusively for the past several months and the R850R sat in the garage. Weather, temperature, etc. You know how it is. Most importantly I've gotten used to how that bike vibrates, which is typical Oilhead vibration...with one more recent caveat listed below.
I swapped the upgraded EV14 injector set I had in the R850R to the R1100RT, reconditioned and cleaned the original EV1 injectors from the RT, and put those in the R850R.
Now the R850R is significantly, noticeably smoother. Didn't touch the valves or the throttle body sync and forgot to reset the Motronic too. It's just a tickle of vibration now and is even tolerable at interstate speeds around 4000 RPM. The R1100RT? Now has more vibration than it did. I'm mildly annoyed at this.
That certainly means I've got a set of imbalanced Tills injectors, right out of the box! All that fretting and this whole thread over that! I think I'm going to send them out for a professional cleaning and flow test, and order another set of parts to clean and recondition the original EV1 injectors from the 850 in the meantime to pop into the RT.
I've been riding my R1100RT pretty much exclusively for the past several months and the R850R sat in the garage. Weather, temperature, etc. You know how it is. Most importantly I've gotten used to how that bike vibrates, which is typical Oilhead vibration...with one more recent caveat listed below.
I swapped the upgraded EV14 injector set I had in the R850R to the R1100RT, reconditioned and cleaned the original EV1 injectors from the RT, and put those in the R850R.
Now the R850R is significantly, noticeably smoother. Didn't touch the valves or the throttle body sync and forgot to reset the Motronic too. It's just a tickle of vibration now and is even tolerable at interstate speeds around 4000 RPM. The R1100RT? Now has more vibration than it did. I'm mildly annoyed at this.
That certainly means I've got a set of imbalanced Tills injectors, right out of the box! All that fretting and this whole thread over that! I think I'm going to send them out for a professional cleaning and flow test, and order another set of parts to clean and recondition the original EV1 injectors from the 850 in the meantime to pop into the RT.
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