Triumphrat

Can anyone help,My t-bird sport as developed a missfire between 2000-2500revs.I've done the usual things like put new spark plugs in,checked ht leads, plug caps,checked air gap between pick-up coil and rotor,but the missfire is still there.I've even had the carbs off and cleaned them.I did notice when the carbs were off that the float height was a little low,but only by 1mm.
I'am thinking about taking it to a dealer but know that will be expensive, any help would be appreciated.Cheers.

parrycm

Number one - check and reseat the connections to all three coils under the tank.

If you still have a misfire then consider the following:

Do you have access to an ignition timing light with an inductive pickup? I.e. one that has a clamp that fits around the spark plug wire/lead to detect when the cylinder is firing. They are actually quite cheap to buy.

If you fit the timing light to each plug lead in turn, and watch the light flickering - you will be able to identify a misfire due to bad ignition, bacause the strobe will flash irregualrly or even stay off for seconds at a time.

And you'll be able to tell whether the misfire is common to all cylinders or just one. Assuming it's just one, then swap the coil for that cylinder with one of the others and test again. If the light shows the misfire has moved to another cylinder, then you'll be say that it's the coil that is faulty.

If it doesn't move then it's likely to be a bad plug or lead or connection.

__________________
Chris

"Panniers can never hold everything you want, but they CAN hold everything you need."

Cheers Chris,
Think i know a mate with a strobe,so will try that.
Forgot to mention it only missfires when you drop the throttle off from high revs to between 2000-2500 like when you're comin into a corner, then powering out under full throttle,thats when it stumbles but clears by 3500rpm.
Revs clean all the way to 7000.
Do you think the carbs need adjusting and what are the mixture screw settings?

Anyway once more back into the garage.

I am having the same issue - does it happen at operating temp?

I am changing my coils this week to Nology. The rep on the phone stated he sells a lot to Triumph owners.

rambo

hi everyone,
i had the exact same problem,tried everything,checked everything.low rev misfire up to 3000 rpm then ran fine.it was a faulty coil.all electrical tests indicated all coils were fine.buy one coil and replace in sequence until it runs.mines fine now.it was that simple.cheers..geoff :hammer: :hammer: :hammer:

Hi,
Yes it missfires,or stumbles at operating temp.
Does'nt seem to miss when it's cold,but at that temp you can't really tell.
Any idea how much one coil would be?
cheers guys.

shedds

mine did it too, coils twice next time nology

Hi folks,
just checked coils n ht leads out.Bare in mind i'm no electrician,but the readings for the coils were all the same.
With my really cheep multi- meter set to resistance 200 ohms they read .8,this is for the primary windings.I tried to check the secondary windings but got nothing at all.
Then i checked the HT leads on 20k ohms and found the readings were different.
No1 4.95
No2 5.01
No3 4.67
Do you think No3 could be faulty?
Any idea how much HT leads are?
Cheers.

Nology coils are about $73 each...

Nology coils are about $73 each...