Ive already started a thread about this in knowledge base but I havent been able to get the info I need. and believe it to be a more technical discussion.

I have just done the PAIR removal, TPS adjustment and replaced some vacuum lines and even before those mods I have needed a carb synch.

However I have fried one of the resistors on the circuit board of my tachometer and it doesnt work. I have the 98 cluster and would like it if someone could measure the resistance of R1 on the circuit board (it is labelled)

I know it may seem like Im asking a lot but its only 3 mounting bolts and 2 plugs to get the cluster off the bike, 5 or 6 screws to seperate the backboard from the black cover and 3 small screws to pull the tach out.
Id say not even 10 mins of your time

Please Help me I am in dire need of a carb synch and cant do it as accurately as I would like without seeing my RPMs

Thank you very much for anyone that can help me

 

Get me a picture of what you need measured, and I'll pull my cluster of and get you the resistance. You can usually tell what the resistor is by the stripes on it, and the color, but if it's too fried, the color might not be legible anymore.

 

Well first this is a rather small forum so reposting to a different section usually will not get you any different answers.

Second Tweety already offered his help and when it comes to the electronics\electrical system, you will not find a more knowledgeable member here.

Finally, I my be a bit slow but why do you need a tach to sync the carbs?
I never use the tach to sync and don't understand what the need would be.

 

Well, I haven't had the time to check, unfortunately... Been running around like a headless chicken, moving offices/building at work... So even if I'm still more than willing, if someone else wants to step in, that's fine by me...

 

msethhunter.. I would greatly appreciate the help if you could and yes its too fried to see the color ribbons. I dont have batteries for my camera so taking a picture wont happen. If you pull the cover off of the cluster I believe you wont have to pull the tach assembly off of the back mounting plate in order to check the resistance.. the circuit board attached to the tach assembly is very clearly labelled and im looking for the resistance of R1.

8541Hawk.. I know tweety is the one of the most knowledgeable members on the forum but he has not been able to get back to me with the info I guess hes been crazy busy which is fine.. second I remember reading somewhere on the forum that to accurately synch carbs it should be done at idle and again at 4000rpm.. If synchronizing at idle alone is good enough then its good enough for me it just needs to get done soon..

and Tweety.. Take care of what you need to take care of first.. your work and your life is far more important than my tach.. as for you and everybody else here I appreciate all the help everyone on this forum has been able to provide me with..

 

Alright, stanby.

My DVOM shows 32 (31.9 to 32.2). Colors are orange/black/black/grey

 

msethhunter you are the man... I just checked and I dont have that resistor on me at the moment so once I get my exhaust all wirewheeled and put back together im takin a trip to radio shack...

thank you for taking the time to do that for me ill let you know if it works when I put a new one in.. by the way did you end up having to remove the tach from the back mounting plate?

 

well its a good thing I just checked the color codes (I appreciate both the readings and color codes) because according to them the resistance would be 30 ohms with a tolerance of 10% which would make your readings make sense (27ohms-33ohms) depending on how much power your DVOM is putting to it.

that also explains why i couldnt find a 32ohm resistor anywhere... but I know I can find a 30...

another thought though as I was searching through the bins of resistors at radio shack I noticed they didnt carry much if anything for 10% tolerant resistors mostly 5% and 1%... now I know 5% will be more accurate but at the expense of what if anything?

tweety... any input on that one?

 

well it turns out the resistor wasnt my only problem with the tach...

so whats next?

 

The tolerance makes no difference in terms of usage... The tighter the tolerance the better, but you loose nothing when using "to tight"...

Yeah, well... I haven't had the time yet, still running around like a headless chicken, but when I get the time to look at it, I'll probably be able to give you a few leads to check...

 

Thats what I thought... well Because I couldnt find a 30 ohm resistor I put 2 15 ohm 1/2watt 5% tolerance resistors in series...dont worry it looks near professional and i made sure to not disturb the leads on the circuit board...

On my hour and a half ride to the cape last night I did notice I had no back lighting for my tach so the next time I can get it apart (if i do it here the other half will kill me) Ill see if that back light is burnt or im not getting power at all to the tach which will give me astarting point..

 

Hello everybody,
I just bought my Superhawk. I ran the bike without the battery connecteed because I was trying to find out if my R/R was bad. Anyway I fried some electrical stuff (stupid I know) and one of the components was my tach. I cannot read the resistance value on the one that fried so I was wondering if the resistor that is mentioned in this post is the one that is closest to the 2 capacitors. Your help woud be greatly appreciated. Thanx.

 

scottiemann, did you ever figure out what was wrong with your tach after all?

 

Holy flying shitballs, that's a 7 year old post.

 

Scottieman last logged in here in May 2016...

 

All good gentlemen. Maybe he has the exact problem and is searching for a resolution. I encourage digging up oldies instead of starting a new thread on the same subject.

 

It also has the advantage of putting lots of relevant info in the same thread a future reader will find, what worked,m what did not, new or different solution for the same problem discovered by a different user

 

I have had my bike just for a month now. I bought it with a dead tach. I found out that the R1 resistor on the tach pcb was fried. The bike had a bad R/R and my guess is that the over voltage fried the R1 resistor on my tach. I have not yet tried whether replacing the R1 with a new one will fix my problem. I'm prepared for the fact that there might also be some other component fried after the R1.

 

I replaced the R1 resistor with a fresh 30ohm one. Unfortunately the tach didn't wake up. Next gonna inspect the components after R1.

Is the rpm signal, going to the tach, supposed to be +5V (high state) or something else? Would anyone have the electric schema of the tach PCB (Nippon Seiki)?

 

The Tach signal is generated at the ICU|
The Diag laid out in the service manual seems to show the voltage expected at the Yellow / green signal wire is 10.5vdc

 

Thanks for the quick reply. If I remember correctly the peak level was below 5V when I last checked the signal with an oscilloscope. I'll have to measure the signal again. It might be that the ICU is faulty in my case.

 

I only meant it that I hoped he wasn't looking for a response from Scottiemann. If it helps if you're not able to fix it yourself I've had good experience with DNA Speedometers out of Tampa. They repaired my FZ1 cluster a few years back when part of it stopped working. Wasn't terribly expensive, quick turnaround, and it worked perfect when I got it back. They also reprogram mileage (IIRC they had to do mine as that was part of what stopped working) with a signed waiver if you needed to buy a replacement.

https://dnaspeedometers.com/

 

I did a few measurements according to the service manual (p.19-9, 19-10):
-Continuity between Black/Green and GND => OK
-Battery voltage between Black/Green and Black/Brown => OK
-Battery voltage between Yellow/Green (the wire from the ICU) and Black/Green, IGN ON and engine off => FAIL
-Continuity between front connector in front and the ICU connector (Yellow/Green) => OK

I still have to remeasure the tach (ICU) output pin to see what the signal looks like when the bike is running (step 4. in the "system inspection" above).

I had a bad R/R and I suspect the the bad R/R (and over voltage) might have fried the tach output pin of the ICU, like in this case. I'm now looking for a second hand ICU to see if this is the case. How likely is it that the second hand unit can be a faulty one as well? I don't know. But what I know is that the faulty R/Rs are common in these bikes and if a faulty R/R can cause a dead pin on the ICU I guess that the possibility to find a faulty one is pretty likely.

Just to mention, the bike runs and drives ok.

 

My 98 had an occasional dead speedo .... testing gave no definitive results. Replacement of the cluster did not resolve it...I cold induce the issue most times with spraying water in and around cluster and the issue also happened with rain.

Im reasonable sure the issues was wiring harness, but crashed and parted the bike before I could prove that theory. My next step was to strip the harness from the bike and deconstruct it to test and replace all wiring that fed the cluster. Not a difficult task per say, but time consuming.

If you go that route I have a very good wiring harness loom source now...they huge type and selection of sheathing they have is daunting but the sales folks are really good at making product suggestions from their line up. You can not buy online without a business account, but they will do small sales over the phone and its very reasonably priced.

The company https://www.techflex.com/ is a trusted supplier

 

Thanks E.Marques! I'll keep that in mind if I need to get into harness stripping..

 

scottiemann still have the bike, but he's been busy with family and career to the point that he barely have time at all, I'll have to visit him and get him back on board.

 

I did some measurements with and usb-oscilloscope (laptop was running on battery because of isolation), here are the results:

I started first by measuring the tach signal from the connector, no dash connected (floating pin), the HIGH state of the signal was around 15.2V:


Next I connected the gauge cluster and measured the signal from the Yellow/Green -wire (on the back side of the gauge cluster), HIGH state voltage level around 15.3V:


The image above analyzed: The signal looks pretty nasty. I suspect that the the correct tach signal is the one in violet below (~52Hz, from rising edge to rising edge @ idle speed). The signal contains a lot of spikes around the suspected tach signal and if you look at the signal base there is some regular variation in the base noise (intervals marked with the dotted red line):


To be able to measure the signals directly from the tach pcb I then opened the gauge cluster and removed the tach gauge pcb module from the plastic frame and connected the wires (tach signal, bat +, bat -) directly to the tach PCB (image below). When measuring the signals on the pins of the IC (TB9226AN) the only signal I found was on pin 5 from left on the lower row. On the pin 15 there was 0.75V. Other pins of the IC were at a steady 0V:


pin 5: The HIGH state of the signal was around ~0.9V and the frequency some how matched the 52Hz of the tach signal coming from the ICU (in the image above). There fore I suspect that this is the incoming tach signal after some filtration:


The outcome of these measurements
The signal from the ICU is not clean. It has a lot of extra spikes and noise to it. The HIGH state voltage level is supposed to be around 10.5V (according to the workshop manual) and now its over 15V. The fact that we can see the tach signal pulse in the middle of everything else still makes me wonder if the ICU pin is falty or not. My guess is that if the tach signal output pin on the ICU was dead we wouldn't see any modulation on the outcoming signal. Is the output pin on the ICU working partially now? Don't know.

The fact that there is nothing happening at the tach pcb module IC pins (besides pin 5 and 15, above) makes me wonder if 1) something from the power circuit has fried -> No operating voltage to the IC 2) The IC has completely been fried. The IC is probably not getting a correct operating voltage at the moment as I suspect it to be around 3.3-5.0V, now only 0.75V at pin 15 (don't even know if this is the VCC pin of the IC).

As I earlier mentioned in this thread the R1 on the tach pcb was fried and replaced by me. Measured today: the other side of R1 has battery voltage and the other side 0V (bat -). Could this be a sign of a faulty cictuit which is grounded or is this correct. Hard to say as I don't have the electric schema of the pcb.

At the moment I'm suspecting that the over voltage (bad R/R) has killed the ICU output pin (at least partially) and this has maybe then killed some of the components on the tach pcb.

Next I'm going to investigate if I can get more info out of the tach PCB and hopefully inspect it further. The workshop manual states that if the signal level is above 10.5V (now ~15V) replace the tachometer. I'm gonna next look for a second hand tachometer pcb module. As the signal from the ICU looks so bad my guess is I will also be looking for a second hand ICU.

Would anyone of you know how the tach signal of a fully working system looks like? A image of the signal would be helpful.

 

My O scope is on loan right now or Id check for you...and truth be told it was a used unit bought at auction so not overly trustworthy, and to add....neither is the operator of it when its in my hands...
I can't tell from what you wrote.. did you jumper the ICU pin to the cluster or go though factory wiring? if you are not isolating just the components and using NO factory wiring..
Its an even bet there is an issue in the wiring or ICU>

Any faulty wiring along the circuit could be causing the noise, and even the ovevolt is you have a 12vdc circuit wire in contact with the signal wire.. burned or broken insulation perhaps...

 

I have a spare tach from a later model, might work, not sure. It's all yours for shipping $