Going to try to complete a project this weekend of going through my whole bike and cleaning/de-oxidizing all electrical contacts. This would include contacts at the devices as well as any cable disconnects. The bike has been running rough and also having some issues with the speedo not working intermittently. I'm pretty sure the speedo is a connection issue so I should be able to fix that, but I'm hoping that by cleaning all connections (for example FI computer connections) I might just solve the other issue as well. At least I'll be able to rule it out...

Any advice, thoughts or suggestions for other stuff that should be done at the same time?

best,
Brad

Remove the speedo sensor from the rear drive and clean the face of it, a build up of crud often plays havoc with a good reading.

Just wait a few minutes and someone will come along and mention that you should use DeoxIT (please note correct spelling...are you reading this TWB?) for your electrical connections. Proven beyond doubt to work.

About speedometer, don`t forget the connector under right side battery cover.

Inge K.

Wasn`t it Deodorant it.

Inge K.

C'mon guys...we have a new member. Try and make this place look a little bit professional, or are we too late?

Well, my advice is: yes, good idea. I had a low-speed uneaveness problem that went entirely away by cleaning the throttle position switch sensor just behind the engine.

It's actually in the manual to do this either once a year or once every 6 months, I forget which. When I have a day when I'm not working and where it is not actually raining I will be doing it myself.

Keep an eye out for cracked or worn hoses, leaking gaskets, you know: Everything that isn't clean and nice and new-looking. At the very least, make a list for future maintenance.

@blakey - Yep, well aware of the magical properties of DeoxIT. One of the many hats I've worn over the years is electronics technician and Wurlitzer Electronic Piano doctor. Restoring a 50 to 60 year old electric piano typically requires multiple treatments on all the pots Good stuff!

Brad

great start brad .....keep at it mate !!!



lols @ blakey & inge

I think I need some Detox my self. Don't start making a list of things to do cause you will go mad.(see most of my posts and you will understand).
Save yourself.
RT.

omg ....rt you dont have deoxIT yet ???



if you cant find any ....ill import it with me on the trip south .



give us a hoy !! eh ?

@ Blakey, I cnduo't bvleiee taht I culod aulaclty uesdtannrd waht I was rdnaieg.
Unisg the icndeblire pweor of the hmuan mnid, aocdcrnig to rseecrah at
Cmabrigde Uinervtisy, it dseno't mttaer in waht oderr the lterets in a
wrod are, the olny irpoamtnt tihng is taht the frsit and lsat ltteer be
in the rhgit pclae. The rset can be a taotl mses and you can sitll raed
it whoutit a pboerlm. Tihs is bucseae the huamn mnid deos not raed ervey
ltteer by istlef, but the wrod as a wlohe. Aaznmig, huh? Yaeh and I
awlyas tghhuot slelinpg was ipmorantt! See if yuor fdreins can raed tihs
too. So, yes, since most of us manage to get it wrong a time or two,
I understand almost everything that's written here.

I have some Charlie, but just can't seem to ever spell it good enough to pass the examiners. I nearly need some more, those little spray packs are too small for a dirty old bike.
RT

Two Wheels Better wrote:@ Blakey, I cnduo't bvleiee taht I culod aulaclty uesdtannrd waht I was rdnaieg.
Unisg the icndeblire pweor of the hmuan mnid, aocdcrnig to rseecrah at
Cmabrigde Uinervtisy, it dseno't mttaer in waht oderr the lterets in a
wrod are, the olny irpoamtnt tihng is taht the frsit and lsat ltteer be
in the rhgit pclae. The rset can be a taotl mses and you can sitll raed
it whoutit a pboerlm. Tihs is bucseae the huamn mnid deos not raed ervey
ltteer by istlef, but the wrod as a wlohe. Aaznmig, huh? Yaeh and I
awlyas tghhuot slelinpg was ipmorantt! See if yuor fdreins can raed tihs
too. So, yes, since most of us manage to get it wrong a time or two,
I understand almost everything that's written here.

Jsut as weel yuo dinni hvae a soccts acecnt ar wood nay heave a sheet sohw en hell of udnresatndin ya.

Purkolator, pay no attention to the riff raff.
I believe they have been taste-testing the DeoxIT again...

Well, I got my chance for a little taste test today. Sunny day with several hours free and I was able to tear the bike apart and do the cleaning.

SUCCESS!!

I realize I didn't mention the issue I was having in the first post, but I've been dealing with crappy low RPM performance since I bought this bike about 6 months ago. For some reason, I didn't feel it on the test ride, but as soon as I got it home seemed to lug at low RPMs. Taking off from stop lights was not fun and typically meant goosing the throttle and being very careful with the clutch. I'd usually feel something "kick in" right about 2500-3500 RPM in 2nd gear or so. Things seemed to get slightly better once she warmed up (10-15 minutes of riding) but still not right. I also had a problem with her wanting to stall at idle once she got nice and warm (like 30+ minutes of riding typically including 10-15 minutes at freeway speeds). She would idle kind of OK for about 20-30 seconds and then start to sputter and eventually die. She would always start right up again though.

So... after the cleaning today... which involved removing the tank, FI computer and battery and then basically following wires until I found a disconnect and cleaning it. Many of the big multi-pin connnctors had globs of di-electric grease on them. I've always read that you are supposed to apply a "thin layer" of that stuff, so I wonder if some of those globs might have been causing erratic current flow. I ended up wiping away as much of the grease as possible, applying DeoxIT, working the connection and then reconnecting. For some of the smaller 1 and 2 wire disconnects, it took some serious elbow grease (and in some cases some needle nose pliers) to pull them apart and then I was greeted with cloud of dusty white corrosion when it did finally pull apart. My guess is that one or more of those corroded connections was causing my problem, but who knows... it could have been that grease too.

Anyhoo, after putting her all back together I took her for a quick spin around the neighborhood and.... YES!! for the first time since I bought this bike... SHE IS FUN TO RIDE!!!!!!

I am jazzed! Thanks for the support and advice (especially JHepburn, your response made me think that I just might be on the right track). I'm excited to continue contributing to this great community!

Ride safe all!
Brad

Nice work Brad!

OG

yay ....nice result brad ...



cheers

Okay, well, maybe not total success.....

Took it for a longer ride today and got her on the freeway for 10 minutes or so. After getting off the freeway and getting her fully warm (note that it was a pretty warm 80 degrees or so today), I noticed some of the old problem cropping up again. Most noticeably wanting to stall at idle (stop at a light and it will idle ok for 5-8 seconds and then start to falter). Interestingly, in the 10 minutes or so of riding before the freeway stint, the engine seemed to idle very nicely (better than ever, in fact) when stopped at a stop light. I also noticed erratic acceleration again after the freeway stint. Might even go so far to say that it might have felt like it was running on 3 cylinders or out of sync... or something. Then it would do that "kick in" thing while accellerating, although much less reliably than before the electrical cleanings. So, it seems that maybe I have fixed at least part of the problem, but still have something discover...

Some observations -
-the "stall at idle" phenomenon may be related to the fan kicking in. It was hard to hear for sure when the fan was on or not, but at one stop light after the freeway, I thought I heard the fan kick on and pretty quickly after the stalling issue started.

-the power loss on acceleration issue has definitely changed in character since the electrical cleaning. Before it was fairly reliable, with power loss at low RPMs and power "kicking in" about 2500-3000 RPM. Now it seems erratic, but somewhat related to engine temp. Starts off pretty smooth with good acceleration from stopped and then seems to generally degrade as engine temp increases. Once warm, however, performance was erratic with some accelerations being smooth, some rough at start and some rough through the band.

-I should mention that I also hear a knock/clunk of sorts that I can recreate pretty reliably by holding the bike at idle in neutral at about 1500-2000 RPM. I don't think it's coming from the fuel return valve on the left front of the tank and after removing the tank it seems that someone has already removed the spring and bearing (pulled the hose and it start spewing fuel, so I had to drain the tank first). It may be coming from somewhere in the airbox or possibly from below in the engine itself. If I get a chance in the next day or two I'll post a video.

So.... Sorry for the lengthy post, but I'm hoping the detail may help in diagnosing the issue. I've gotten a taste of the potential of this bike now and I'm hooked into getting her sorted!

purk....did you do the temp sensor connections ?



the cable connects to the sensor at the verticle stub ,,,,which sits behind the radiator .....sort of in front/adjacent to the start of the plenum chamber . by removing the right hand air intake you can see it from that side with a torch

its a tricky little devil with 2 sensors inside ...the body connects to the tube (stub riser) so make sure that is good also ......



secondly did you do the airbox connections to the afm (air flow meter) there are a number of sensors in that lot ,,,air intake temp and flow ....its in the top cover of the air box and again accessable from the right hand side .



hope that helps



i

Quick update...

First off, Charlie99... I had missed that multi pin connection on the afm, pulled it off and cleaned up those connections. I had done the temp sensor connection you described. After doing the afm connections I decided to check the adjustment of the throttle position sensor and found it to be not quite clicking when the throttle closed. Adjusted that for correct operation.

After putting it back together again I took it for a quick spin and the rough running was still there, but now right from get go and she wanted to stall at long stop lights sooner than before. Still seem to kick in a bit after enough throttle. Before kicking in it was kind of feeling/sounding like it was running on 3 cylinders.

So... Today I started playing with the plugs. At first couldn't find the right spark plug wrench so just pulled plug wires to see if i could figure what was up. If I pulled either 2 or 3, she would sputter and die. Pulling either 1 or 4, she would falter but keep running (a bit worse when pulling 4). Ran to the store for the right wrench and pulled the plugs to find 1 black and sooty. I should note at this point that injector o rings were replaced recently due to visible leak on injector 1. While I'm at it, i'll let you know that intake manifolds were also replaced recently as well (although rubber boots on top of throttle bodies have not yet been renewed). So... Cleaned up the offending plug with some sandpaper and reinstalled. Took her for a quick test ride and she seemed to be running quite a bit better. After lunch took her for a bit longer test ride and stopped at the store to pickup some new NGK plugs. After installing those, she seems to run a bit better yet, although still not quite right. Throttle response, power and idle seems better (no dying at stop lights yet) but she's not as smooth as i'd hope. For example low speed parking lot maneuvers are pretty hard to perform smoothly. Throttle seems touchy when trying to apply a bit of power and kind of inconsistent when holding steady (cruising down a road at a steady 30mph for example). Maybe I'm spoiled by the super smooth throttle of my last bike (2000 ST1100) but I think she should be capable of better. She is running much better now but I ache to eek the best out of her

Going to try to take her for a longer ride tomorrow and then take a look at the plugs again. Any thoughts as to what's was and/or is going on?

Thanks
Bra

If you haven't already done it put new plug leads in and check the connectors where the leads go into the coils for corosion.

I just use the blue silicon leads available from just about any auto store and a resistor type plug. An NGK plug with a R in the code is a resistor plug.

hmm theres a couple of points that should be addressesd there purk ...as k freak said replace the leads ...

i think youll find that number 1 like mine is only partially working ...which really affects things ...

secondly the top rubbers could well be affecting the mix ...

thirdly ...i have suspision that the number 1 plug being black may be pointing to an injector/valve issue ....but could just be the lead is past it ...

i have measured the plug lead lengths ...and found that ...if you can get the same right angle connections onto the plugs they should measure 310 mm for number 3 .. 370 mm for number 2 and number 4 (number 4 folds back on itself ) and 385 mm for number 1 ....

but if you can only get the standard type straight connections add about 40 mm to the lengths ...(probably wont be able to get them that close to measurement ....but you get the idea ( the standard types are really cheap ...about $5.00 each out here so it shouldnt cost much to see some differences .)

good work replacing the plugs thats a good start


mentioned above was also the breather from the crankcase to the plenum .....its hard to get at ...but definatly worth checking again and if need be, get a new one ....

good luck mate ....these babys purr when going right ...and im a bit mystified that you cant get a nice idle .....but work at it mate youll get there ..


hey im no expert ...but would like to see you appreciating the awesomeness of the k100 real soon


cheers

Maybe this is wron topic but I have quite same problem, but I can't say that my K100RT -85 has rough runnin, more like twitching and coughin randomly.
-The engine fire normally
-Acceleration is good
-Idle running is good (exept randomly coughing)
-Fuel consumption is 5.3l/100km.
But when I drive slow speed, engine do some annoying coughing and that same I can feel also in higher speed like twitching.
What is new:

-New injectors
-New coils
-New pressure regulator
-New plugs
-New plugs leads
-New temp sensor
-New throttle body switch

What is checked:
-Ignition timing
-Fuel pump
-Fuel filter
-Fuel return valve
-Throttle body cleaned
-Throtle body balance
-ECU changed
-No air leak
-Air sensor changed
-All cable connectors and earth point under tank is checked

Next I'll try to chage ICU which will be in my mail box today, wish me luck
Luckily I got ECU and ICU sekond hand parts from Motorworks UK for reasonable price.

5.3 liters per kilometer ....wow ...that s thing must be breathing fire out the back ........crikey !!!!



good luck with the icu .....that may help !!!!


but sounds like the computer (under the seat ) icu .....might be getting poor signals ...to me




cheers

could be a slight air leak with the engine breather hose had similar issue old hose looked fine till I took it off

Well, I have changed parts more than I can remember.
Lets add engine breather hose as well in my previous lists.

With new(second hand) ICU and after about 70km test drive, first feeling is that my K100RT -85 coughing and twitching problem is solved.

Need more test drive to be sure.

Now she run smoothly in slow/idle speed and my joy to drive is back.

good result towu......... lets hope purkolator ahs some success soon .....

Well, the 16 mile commute to work this morning revealed a much better performing bike. The surging (that "kicking in" I was describing) is probably 80-90% gone and I can only really feel it at low speeds (like getting on the freeway onramp in traffic this morning).

Also, the stalling at stop lights is gone. Idle was nice and strong after my ride in. So here is my relatively uneducated guess about that. I'm thinking that at idle, the fouled plug wasn't producing as much spark as it should and would slowly get overwhelmed by the spray of fuel, eventually bringing idle down and dying. Am I way off?

I'm interested to see what the plugs look like after another ride or two. I'm thinking if plug 1 doesn't start fouling up within a few days, I might just get a full tune up done and see if that does the trick to get rid of the rest of the strangeness. I haven't had a full service, per se, since I bought the bike so it's probably a good time.

Brad

Oh yeah, forgot to mention that I put about 1/3 bottle of Seafoam in the tank (nearly full) this morning to see if that helps anything. Just FYI...

did you use ngk d7ea purk ?



i would be changing its brother in number 4 as well (wasted spark affects both )

If you go to a shop to get a 'service' they'll only do what anyone would do, and that is change the spark plugs, check or change the air cleaner, point a strobe light at the timing marks, change the fuel filter, and most importantly, check the valve clearances. If not only to change them but inspect them to know for certain they're not causing your initial troubles. If you're chasing a running gremlin in your motor all of these basic things should be a part of that pursuit as well as cleaning contacts and tightening connections. As you well know it's a process of elimination and note-taking until you identify and corner (and kill) the little bastard that's ruining your day.

@Charlie99 - yes, NGK D7ea. Replaced all 4.

@TWB - indeed, that's basically what I'm hoping is to rule out any deeper issues. Will likely get a compression test as well to make sure all is well there (Once was done a few years back according to the service records, but a lot can change in a few years). Don't have the tools or time to do all that stuff so it's worth a bit of change to make sure I'm not chasing my tail.

Try that bloke in Ballard. The Pom. I forget his name. Used to work from his house in Fremont.

Mick Vallantine. Good guy and good mechanic. He's did the steering head bearings for me when I first got the bike.

http://vallantinemotorworks.com/

Don't think he's a Brit, though. In fact, I think he hails from your neck of the woods TWB. Regardless, he is the guy for Beemer work here in Seattle if your not into paying dealer prices. Good indicator of his quality of work is that all the local bike cops with Beemers use him.

seeing that you have found corrosion in all the likely places brad ...i wonder if youv checked all the low voltage coil wires ,,,

their just a push on arangement behind the coil cover ...at the bottom

if you have a multi meter try and measure them there are 3 terminals earth of corse ...then the 2 primarys ...should be 2.4 ohms around about .....take off the secondays (high tension leads ) and measure the output ...should be about 10-11k between the two posts ..(may have to get paper clip jammed in there to measure it)



might be worth a look mate .....takes me time to have a brain storm .... at work we say "the impossible we can do immediatly ....but miracles take longer "...



way too tired here ...wake me up when "married with children" is on ...i need a laugh ........zzzzzzzz

Mick, that's it, but he's not Aussie. English midlands if I correctly recall our convo of ten, eleven years ago, back when he was still working in his basement. He's come a long way.

OK, time for another update. I've done the commute a couple times this week and have some new behavior to report post spark plug change. Now when I start up in the morning, the bike sputters a bit idles pretty low (600 or so w/out choke, 900 or so with choke). I typically have to use a bit of throttle to keep it running for the first minute or so. I'll leave her to warm up for 2 or 3 minutes while I don my gear and then take off. For the first 2 or 3 miles I get pretty erratic throttle response. That surging is back. Taking off from a stop sign takes a bit more throttle and clutch feathering than it should. After a few minutes though, things seem to clear up almost entirely. I say almost because there is still the slightest bit of surging that I can feel when cruising at steady speed. It's not enough to really cause any real issues but I can just kind of feel it in the throttle.

Another new issue is some occasional backfiring on hard decellerations with downshifts. Never heard that before the spark plug change. Interesting.

I'm out of town next week so holding off on that tune-up/service until I get back, but I am going to go grab a compression tester and do that before I head out just to be sure I don't have deeper issues brewing.

With erratic running at low revs check for air leaks with butane or propane or inflammable carb cleaner applied to all the potential leak spots. Check the electrical connections to the fuel pump at the small plug under the tank,that can prove to have contact sockets which are stretched and not making good contact. Then I would take a look at the air flow meter to check there are no wear points which are interfering with the smooth resistance change.
Regards,
K-BIKE

Maybe I'm getting this wrong, but are you starting the bike and running her whilst the idle is at 600?? The idle should be 950 (+/-50) rpm, so if to low you would use the choke (rev increaser) to ensure the idle is right before setting off.
During starting the bike fueling is controlled to the temp sensor in the AMM and only after reaching 700/750 rpm takes the normal management over.

thinking its an hall sensor or ecu issue ...(under tank )

OK, another update. I ran down to Sears, grabbed a compression gauge and did a compression test today. All seems good with right about 175psi in all cylinders. I did, however, notice that all my plugs are starting to look a bit black. Not the nice tan color that they should be. This is after only about 60-80 miles since putting brand new plugs in. Considering that, plus the fact that I am getting some backfiring on hard engine braking (TPS seems to be set correctly with a click just as throttle opens) it seems to me that at this point that my big problem is that I am running rich.

I'm trying to recreate the sequence of events in my mind and correlate the changes in performance...

1. I buy the bike. Runs "ok" but a bit rough. Seller says he thinks the intake boots need replaced (parts included).
2. I discover that the head bearings need replaced as well so I take it into the shop and have both the head bearings and intake boots replaced (I SO should have had him do the throttle body /air collector rubber at the same time, doh!). Throttles are synced on reassembly.
3. After that, the bike runs better but still not right.
4. I discover the fuel injector O-ring issue at injector 1 and replace all 4 sets of those. Throttle bodies are synced again. Still doesn't run quite right.
5. I do the full electrical cleaning and things seem to run better for a short test ride.
6. Next day on another test ride, things seem worse again, but not as bad.
7. I pull the plugs and discover plug 1 is fouled black.
8. Replace all plugs and she runs quite a bit better, but still has some hesitation/lack of power at low RPMs while warming up. Typically after 10 minutes of riding, she runs pretty darn well with just a hint of something wrong that I can feel in the throttle response (very slight surging).

and that is about where I'm at now. So, I'm a bit confused because if I'm running rich, shouldn't it run relatively well at startup. I mean, isn't that basically what a choke does, make it run a bit rich?

Anyhoo, I am off for a few days for a family vacation (I'm going to Disneyland!!) so I won't have any more updates for another week or so, but I'll be eagerly following the thread and making myself a list of stuff to try next weekend.

thanks all!
Brad

Back from vacation today and had time to double check air flow meter operation. I metered the pins of the unit and saw the expected impedances. Vane seems to be in good operating condition and not sticking. Reinstalled AFM, cleaned off sooty plugs and took her for a test ride. Still some surging, even after warming up. Pretty sure the AFM is good, although I do hear a strange sound....

At idle, if I hold the RPM about 2k or so, I can hear the AFM vane snap shut every so often. I wasn't sure what it was for a long time (suspected the fuel return valve for a while but it was on the wrong side) but after taking the AFM out a couple times it sounds just the same as when I open the vane and let it snap shut when it's out of the bike.

So, what might be causing that behavior? I opened up the AFM bypass screw a bit in hopes of leaning things up since I have carbon fouled plugs. We'll see how that goes, but I'm still hearing that sound and still having that surging. Hmmm....

Thanks in advance for any additional advice you might proffer....
Brad

purk.....i think the spinging in the vane could be the issue ....the wiper of the afm as you said would keep the same impedences ....but the vane springing (read as resistance to flow) could well be the issue ...i havent seen a bad vane spring myself ...but by your description sounds ominously like it could be the issue .



there are a few links around the place to performing richness adjustments through the position ....tension and preset of the afm mechanics/electronics ...and a few pics as well .



pity you couldnt borrow one to try for a couple of days ....is this possibly an option ?



good luck !!

might be off track but whats the air filter like?? is it original or a foam K&N you could try running without it see if it improves . Else try a plug chop basically put in new plugs and whilst doing a high speed run turn off motor then stop and take plugs out see if still running rich . Also what is the spray from the injectors like or is it just dribbling

cheers Tony

i am sorry for not caring about your issues purkolator but i wanted to ask you guys about how to check the impendances in the air-flow meter? do i have to take it out to do it? i have some similar issues with my K but what i am guessing is the air leak. thanks for any suggestions.

cheers

pajonk wrote:i wanted to ask you guys about how to check the impendances in the air-flow meter

Here you got it.

Inge K.