[phpbiker]

Hi Guys,

A friend lent me his 96 Daytona 900 for a couple of days to try out before buying one one myself.

I love the bike, but this one has developed an intermittant fault.
I was wondering if this was a common problem amongst these bikes. And perhaps if you guys knew what it might be if it was a common fault.

Basically at speed the bike is 100%. However, in traffic at low RPM's the bike will die at times for no apparent reason. The rev counter can even drop from like 2 to 3K like a stone ...you get nothing, go on the button and it will swing over quickly and occassionally bang and pop, then..for no reason with no change (clutch in or out) it will just start and run..till the next traffic lights where it may fail it may not. Some times it actually dies at low speed when running in gear with low revs.

THe only solution is to keep the bike above 3K all the time.

Any ideas? Anyone seen anything like this?..and now how to fix it? LOL

 

[bradtx]

phpbiker, Sounds like your frind needs a tune-up which includes sync'g the carbs and a check of the shims. Routine maintenance on any motorcycle.

Brad

 

[phpbiker]

Nah man.

Its not a misfire or a gentle decline. Its complete ignition electrical death. The rev counter drops like a stone and the motor dies completely, misfires on the thumb and then comes back to live for no reason.

Besides that its meticulously serviced by a long standing local dealer. Shims done and carbs balanced on last service done early I beleive.

so far from searches and research I'd put money on it being the ignition pickup. I had one go once on Honda with very similar symptoms. Are they known to fail on these bikes when they are warm?

 

[bradtx]

phpbiker, That's different from what I was thinking. I don't know about the earlier Daytonas, but with the '97-'01 the CPS can cause similar problems when hot, primarily failure to start.

Brad

 

[phpbiker]

Crank Position Sensor..is this effectively a CDI pickup in the modern world? LOL

 

[djw]

Doubtful it is a crank sensor (ignition pick-up coil). When these go out, it's off like a plug was pulled.

Take the question to the T3 Sport Touring forum where all the original T3 900 drivers reside.

 

[phpbiker]

Yes thats what its like.

It drops like a stone like you hit the kill switch, but its rev dependant. Anything under 3K and it may go at any minute, over 3K its rock solid no performance loss at all.

You go to start it on the thumb and it spins over no ignition at all with occassional "wumphs" and then will just run up as if you turned the kill button back on. (or is that off ? LOL)

If it was the button itself then it would be dying at whatever revs at least some of the time. Same with any other switch or connection.

Cant be carbs because there are no misfires or bad running AT ALL.. Its total death.

Is it true they have a rep for knocking these sensors out in high temperatures? Like heavy traffic on a 28 plus degree days?

Thanks for your suggestion about the forum, I am still getting used to the layout

 

[djw]

I have never heard of a ignition crank sensor (pick-up coil) being rpm intermittent when working. My only experience is they go bad when they are hot and work when not. It is an easy fix and if it has not been replaced since new it will go bad someday soon, so it can't hurt to change it out. Just make sure it is gapped correctly, and it might not hurt to check that the one on their now is gapped right.

I have also never heard of 3 ignition coils being bad at the same time.

 

[daytona 750]

the pickup coil will be fine when cold, then drop out of action when it gets up to temp, and only start 10 20 minutes later when the engine has cooled.
it does sound electrical to me, but as said previously, you wont get 3 coils all failing at the same time repeatedly.
it sounds more like a short circuit, that is made(or broken) at certain revs when it causes a specific vibration to the effected part of the loom.
just a guess, but start at the kill switch and work through all the wiring, then move onto the ignition switch and safety switches.
good luck in sorting this one out, and please keep us up to date with any progress

 

[djw]

As D750 says, make sure all the safety switches and such are not sticking if it truly is cutting off like you say. More than one has been bitten by a side stand switch not working properly.

It also make sense to verify your vacuum petcock is working properly and the hose from the carb top does not leak - this is what opens the petcock, and a lack of vac closes the petcock. If the petcock is working (knob not knackered on the inside and truly turns the valve) you can validate it is not the problem setting it temporarily on the prime position. Even still the petcock is not like a kill switch thrown, it is like running out of fuel when you run the bowls dry, it poops out over few seconds.

 

[phpbiker]

Yeah thanks DJW.

All the wiring and relevant switches are being checked.

Although at this point I ought to tell you I spoke to a Triumph Specialist (independant..like they are the guys that know right?) and he sells two CPS's a week for fitment to mid 90's T3's.

So it seems they might be coming to the end of their natural life around this period..perhaps..

Anyway, definately a good idea to rule out any other interconnected problems before trying the sensor. I've had more than one thing wrong at the same time before on other bikes.

 

[djw]

Although at this point I ought to tell you I spoke to a Triumph Specialist (independant..like they are the guys that know right?) and he sells two CPS's a week for fitment to mid 90's T3's.

So it seems they might be coming to the end of their natural life around this period..perhaps..

I agree this part is a very common failure for this age bike. One of mine died last month. However, I have never heard of one acting like yours, they quit working when hot and work for a few minutes when cold. You would get a prize for the strangest failure being RPM related. If he can bum a Triumph Ignition Tester tool it is also apparent to verify it, and if you heat it up a little you can put an ohm meter on it and watch it go out of spec when hot, back in when cold (at least on mine).

$60 bucks to replace the part and it is an easy install.

And don't toast your sprag trying to start it to death, you won't like that repair at all.