Honda Motorcycles - FireBlades.org banner

1 - 16 of 16 Posts

·
Registered
Joined
·
2,517 Posts
Discussion Starter #1
Where does the ecu get the rpm signal?

Is it from the ignition pulse generator or cam pulse generator? Or something else?
 

·
Premium Member
Joined
·
32,034 Posts
Where does the ecu get the rpm signal?

Is it from the ignition pulse generator or cam pulse generator? Or something else?
At a guess it could be either, but if I were designing it I'd take it from the cams. They're spinning half as fast so the signal should be more precise.
 

·
Premium Member
Joined
·
32,034 Posts

·
Registered
Joined
·
6 Posts
very keen to see the answer to this question.

954 track bike speedo and tacho do not work. I was going to put a Gizzmo shift light on just for shifting on the straights but it definately needs a pulse feed of some description.
 

·
Premium Member
Joined
·
32,034 Posts
very keen to see the answer to this question.

954 track bike speedo and tacho do not work. I was going to put a Gizzmo shift light on just for shifting on the straights but it definately needs a pulse feed of some description.
Why don't they work? Is the speedo dead or it just reads zero all the time?
Is the speed sensor in the top of the transmission and is it connected?
 

·
Registered
Joined
·
6 Posts
sorry to hijack your thread burton

I just bought the bike. Apparently speedo and tacho were working at one stage. It has had a right hand lowside minor damage to fairings only, damaged tip over sensor that will be replaced (Fuel pump wouldnt prime, traced it back to tip over switch, bit of a tap and bike is running fine)

Everything else works on the dash except the speed and tacho. Reads 0 kmph

Speedo sensor looks ok plugged in but havent checked it yet, i get 0v constant at the pink/green wire at the dash even when turning the back wheel by hand

Tacho wire at the dash reads 1.3v no matter how much throttle applied.

I would be happy with just a shift light but need a signal from somewhere

Either ipg, cpg, ecu, tacho wire?

Thanks for your reply
 

·
Premium Member
Joined
·
32,034 Posts
sorry to hijack your thread burton

I just bought the bike. Apparently speedo and tacho were working at one stage. It has had a right hand lowside minor damage to fairings only, damaged tip over sensor that will be replaced

Everything else works on the dash except the speed and tacho. Reads 0 kmph

Speedo sensor looks ok plugged in but have checked it yet, i get 0v constant at the pink/green wire at the dash even when spinning the back wheel

Tacho wire at the dash reads 1.3v no matter how much throttle applied.

I would be happy with just a shift light but need a signal from somewhere

Either ipg, cpg, ecu, tacho wire?

Thanks for your reply
You don't have any error flashing though?
Do you know if it's got stock cams?
If you're not getting a signal to the speedo then you can probably rule out that as the problem.
You might have to pull the speed sensor out of the transmission and test it.
You can just run an aftermarket tach and leave the OEM instrument cluster out. I don't usually run mine on the track.
 

·
Registered
Joined
·
6 Posts
Thanks blade

Dont know about cams, it is a jap spec engine, it is lumpy warming up then evens out once at about 60 degrees celius

yep ill have to check the speedo sender next.

What wire do you hook up the aftermarket tacho to? What brand / model do you use?
 

·
Premium Member
Joined
·
32,034 Posts
Thanks blade

Dont know about cams, it is a jap spec engine, it is lumpy warming up then evens out once at about 60 degrees celius

yep ill have to check the speedo sender next.

What wire do you hook up the aftermarket tacho to? What brand / model do you use?
Was just thinking that if the cams have been replaced they might not have a cam rotor on them. I don't know if that would cause an error code though.

I don't run a tach at all :)
You can get some really tiny LCD instrument clusters which are pretty neat but I'd prefer to run a full size sweep dial as I only watch it periferally.
 

·
Registered
Joined
·
6 Posts
no error codes as yet

I will take it out down the local quarry road this weekend and suss it out.

I was thinking no tach as well after all this, just shift when it bounces :evilaugh:

Thanks for your help i will continue to probe and let you know

Cheers
 

·
Premium Member
Joined
·
32,034 Posts
no error codes as yet

I will take it out down the local quarry road this weekend and suss it out.

I was thinking no tach as well after all this, just shift when it bounces :evilaugh:

Thanks for your help i will continue to probe and let you know

Cheers
If you don't have a tach signal the rev limiter may not work though, I don't rev mine that high to know.
 

·
Registered
Joined
·
6 Posts
ok guys

replaced the dash/gauge cluster with a second hand unit and the speedo now works but still no taco.

anyone out there able to shed some light on the rpm signal.

My next step short of checking the connectors again is replacing the ecu + key (hiss) to try and get a signal
 
1 - 16 of 16 Posts
Top