Triumph Rat Motorcycle Forums banner

1 - 15 of 15 Posts

·
Registered
Joined
·
9 Posts
Discussion Starter #1
Hi Guys, I have an 07 Bonneville (Last of Carbi model) I'm having trouble with it dying mid ride, no sputtering just stops, when I flick the petcock over to reserve, she fires back up and runs fine, this happens intermittently. We have cleaned the petcock, no dirt all really apart from a few specs, looked at electrical, thought perhaps the breather on petrol tank cap was not working and causing a vacuum, so I am stumped, I taken to 2 bike shops for repair but to no avail. Any suggestions would be appreciated, thanks and cheers. Bernie
 

·
Super Moderator
Joined
·
1,766 Posts
Just few items to check off the top of my head.
1. Engine Speed sensor.
2. Coils
3' Fuel related - Vent line blockage on the vent to atmosphere hose that runs from the aluminum balance tube down the back of the frame out the left side. Tendency to get clogged or pinched by the holding bracket.
4. Also fuel related - The fuel supply line from petcock to carbs inlet and the very small inline fuel filter at that point.
 

·
Registered
Joined
·
549 Posts
Just few items to check off the top of my head.
1. Engine Speed sensor.
2. Coils
3' Fuel related - Vent line blockage on the vent to atmosphere hose that runs from the aluminum balance tube down the back of the frame out the left side. Tendency to get clogged or pinched by the holding bracket.
4. Also fuel related - The fuel supply line from petcock to carbs inlet and the very small inline fuel filter at that point.
 

·
Registered
Joined
·
549 Posts
Does this occur after riding a while? Engine warm/hot? When the coil is going bad you will get this behavior. Maybe the petcock helping is just a coincidence.
 

·
Super Moderator
Joined
·
1,766 Posts
Yes all those items can occur after riding and warming up. Yes, if you inspected the petcock and it is clear and flows freely I would call that just a coincidence and more likely just the amount of time to let whatever is failing regroup.
If you are certain your fuel system is not restricted head to the two electrical items. Either have been know to give people problems. Intermittent problems that are tough to track down.
 

·
Registered
Joined
·
549 Posts
Usually when the coil is going it won't start back up until it cools down a spell. The fact that his fires back up right away suggests something else. However, I would bet dollars to doughnuts it's one of the 2 electrical items you have highlighted.
 

·
Registered
Joined
·
1,621 Posts
There were a few posts quite a while ago with similar issue, although the cure might just apply to efi models. The problem was caused by the seat base pressing on the electronic components under the seat, rider gets off and problem goes away for a while. Like I say, maybe just efi as there is more under there but thought I'd mention it.
 

·
Registered
Joined
·
9 Posts
Discussion Starter #8
Just few items to check off the top of my head.
1. Engine Speed sensor.
2. Coils
3' Fuel related - Vent line blockage on the vent to atmosphere hose that runs from the aluminum balance tube down the back of the frame out the left side. Tendency to get clogged or pinched by the holding bracket.
4. Also fuel related - The fuel supply line from petcock to carbs inlet and the very small inline fuel filter at that point.
[/QUOT
 

·
Registered
Joined
·
9 Posts
Discussion Starter #9
After thinking a little more over night, its not coughing and spluttering as if is short on fuel, therefore that leads me to electrical, any tips to checking the Coil and Engine speed Sensor?
 

·
Super Moderator
Joined
·
1,766 Posts
Sometimes fuel issue is just running out of fuel and the engine just slowly dies.
As for the two electrical items which is my guess where you should be looking a service manual gives the instructions to trouble shoot. The coils and speed sensor are just a resistance check. Preferably hot and cold conditions.
A good point was brought up a couple posts ago. There were some issues on bikes having the computer under the seat have wires that due to the seat rubbing on them would go open on the carb bikes. Seemed due to the rider or riders weight and or seat position the seat base could hit the connector. Definitely worth a look into. Maybe just the connector loosening over time even.
 

·
Super Moderator
Joined
·
1,766 Posts
Here is some notes I had saved.
Coil resistance checks.

If you still have the original GILL coil the specs are as follows

Primary resistance 0.5 ohms nominal
Primary inductance 2.5mH
Turns ratio 85 to 1
Dwell time 2.1ms max
Peak current 10.5A at max dwell
Spark energy >60mJ at max dwell

Secondary voltage 35kV max
Secondary resistance 2.155 Kohms
Connections 6.35mm spade terminals. (LT polarity must be observed)

When you measure such low resistance as in the primary winding, the resistance of the test meter leads has to be taken into consideration. Short the probes together firmly, note the reading and subtract that figure from whatever you get from the primary winding.
A typical figure for test lead resistance is around 0.3 Ohms.
The secondary has a wide tolerance, as much as +-10%, by the way.
The HT wires have no appreciable resistance, they're copper-cored. The plug caps are 5 Kilo Ohm each.

The primary resistance has to be measured at the two FAST-ON tab terminals using a multimeter set to low ohms. Because of the low value the test lead resistance becomes important and has to be determined to be able to correct final reading. Short the test leads together and make a note of their own resistance, this can be as much as 0.3 Ohms. Deduct that figure from the resistance you get on the primary.

Using pointed test probes, insert one each into the plug caps making sure they touch the metal terminals inside. This measures several things at once:
The plug caps with their internal resistors (5 kilo Ohms each)
The soundness of the high tension wires ( made of copper-cored cable with negligible resistance)
The secondary coil winding (around 2.2 Kilo Ohms)
You should get a total resistance of around 12.2 Kilo Ohms.
Note that coil windings have a wide tolerance, as much as +- 10-15% of the theoretical values, so don't worry too much if it's not exact.



Specs from Gill Industries technical sheet:

Primary resistance 0.5-0.6 ohms nominal

Primary inductance 2.5mH
Turns ratio 85 to 1
Dwell time 2.1ms max
Peak current 10.5A at max dwell
Spark energy >60mJ at max dwell
Secondary voltage 35kV max
Secondary resistance 2.155 Kohms
Connections 6.35mm spade terminals. (LT polarity must be observed)

There are alternative, after-market coils available from PVL (also sold as Nology) and their specs differ a bit:

High voltage supply: > 21 kV
Max. spark energy: 30 mJ
Primary resistance: 0.6 ohm
Primary inductance: 1.65 mH
Secondary resistance: 8.7 kOhm
Secondary inductance: 9.2 H
 

·
Super Moderator
Joined
·
1,766 Posts
Some more notes on a general way to check speed sensor output.
Proving signal from the trigger in flywheel

Here is a simple diagram of one that works for those that can read a circuit diagram.
Would recommend a higher voltage capacitor but I was only proving signal from the trigger in flywheel so only a few volts. Spinning the engine is required to produce pulse. Slight amount of oil on the trigger may help.



Input on left and meter plugs in on right.
I used alligator clips to go on bike and separate banana plugs for my digital volt meter to measure the resultant DC voltage.
Buy the 4 diodes and make a full wave model.

The push button is there to discharge the circuit so you won't get back EMF when you move the leads. Can hurt or sit you on your ass when testing the coil input.



 

·
Super Moderator
Joined
·
1,766 Posts
Some more notes on the speed sensor.
Ignition pick-up coil / Crank position sensor :

A cursory trawl through the forums shows this component to be responsible for no end of problems on Bonnies. I can't understand why this should be so. Similar devices have been used on all manner of bikes for donkey's years and they mostly last the life of the engine. It's a relatively simple, passive device with no moving parts. The working principle was worked out by Michael Faraday as long ago as 1821. Another mystery of British electrics...

WHAT IS IT AND HOW DOES IT WORK?

This simple component is just an assembly consisting of a metal bracket holding a plastic housing that encloses the two active elements in it: A coil of very fine enameled wire wound around a magnetized iron core. It is in effect a tiny generator stator.

I have got hold of a spare one and close examination shows a well-built, robust and well epoxy-sealed assembly that should be reliable. I can't see the windings inside though, so this is where the troubles could stem from, cheap enameled wire or faulty soldering or strain-relief of the many turns of very fine wire necessary to obtain the sort of resistance and inductance values required in such a small component.

On carbed models Triumph call it an "Ignition pick-up sensor" and on EFI models it's called a "Crank Position Sensor". Other manufacturers use names such as "Pulse coil" or "Pulse generator".

It's actually the same component on both: Part number T1290131 and costs ($79).

On both models it's positioned inside the triangular cover on the right of the engine and fitted very close to the alternator rotor.

On carbed models the rotor has some metallic strips bonded to it called reluctors that pass very close to the magnetic core as the rotor turns. Everytime they do this a tiny electrical pulse is generated and sent to the igniter. This signal is processed by the program or map loaded into the igniter to work out the moment of ignition and the degree of advance and retard to be applied, depending on engine revs. The advance and retard function is entirely electronic, unlike the old centrifugal weights system. No moving parts, just time-delay circuitry that applies more or less delay to the received signal.

On EFI models it also sits close to the rotor but this is fitted with a toothed wheel. Everytime a tooth passes the sensor it also sends a signal to the Electronic Control Module (ECM) and it's used not only to work out the ignition timing but the moment of fuel injection as well. Between the signals sent by this sensor and the MAP sensor (manifold absolute pressure) the ECM knows exactly in what position the crank, and herefore the pistons, are at any given moment.




DATA, TESTING AND FAULT-FINDING

If the pick-up sensor is on the bench like the one in the photo the resistance can be measured using the multimeters probes. If however it's still fitted to the engine the connector can be difficult to access, being stuck between the right hand seat rail and the top of the airbox. Brilliant bit of engineering this...

Unplugging is often impossible without further dismantling. You can see the two wires that go into the connector though, so you could just use the following method:

Using a couple of pins prick the insulation of red and black wires under seat tube above the airbox. Drive the pins deep enough to pierce the insulation and contact the conductors inside the cable. Connect the multimeters probes to the pins and set the meter to the appropriate Ohms range.

The quoted resistance to be expected is 560 ohms +/-10% at 20ºC .This means you should see somewhere between 504 and 616 Ohms. If you measure it with the engine hot the resistance would be higher, as much as 640 Ohms or so.

You could even measure the voltage output with this method. Just ensure the two pins and meter probes are not short-circuited, set the meter to a low DC volts scale and start the engine. You should see at least 0.6 volts although at idle this would be pulsating and the digital readings difficult to pin down.

This nice drawing I've found shows how the pick up generates two pulses: one positive and another negative, the first one as the reluctor first meets the pick-up coil and the second as it leaves it:




A simple tester can be made using a couple of green LEDs that will detect any pulses above around 2.2 volts, both the positive and the negative pulses will show up as the LEDs light up alternatively as the engine is cranked





The gap for the pick-up coil is quoted in service manuals as 1.0 mm +/-0.20 mm but was changed during production due to warranty issues. The following was sent out as a statement by the Factory in a technical release to dealers:

Affected Models: Bonneville/T100, America, Speedmaster, Thruxton and Scrambler.

Should a bike (see above) demonstrate faulty ignition coil type symptoms (most commonly an engine misfire), please initially check and adjust the ignition pick-up (IPU) air gap (we recommend an air gap of 0.8mm).

Since changing the IPU air gap in production to 0.8mm, we have had no ignition coil warranty claims.


As far as I know this only applies to carbed models with chronic ignition faults, often blamed on the ignition coil.

The 2008 service manual of which I have a copy, only covers bikes up to 2008, including EFI models, and the gap is still quoted there as 1.0 mm so maybe that technical note came out later than 2008.

The pick-up coil to rotor gap is set by positioning the alternator rotor with a reluctor strip facing the magnetized core and measuring the gap with a suitable feeler gauge. If found to be incorrect the fixing screws are loosened slightly, not too much, but enough to enable the component to move a bit, ensuring the feeler gauge is a firm sliding fit between the two points and re-tightening the screws to 10 Nm (7.3 Lbs/Ft). Re-check the gap after tightening.



 
1 - 15 of 15 Posts
Top