Bonneville America Forums Forums Technical Forums General Tech Can I Bump Start My EFI Bike?

I'll start off with my standard disclaimer by saying that I did not do all this work by myself. I have perused some websites, and gathered up this information to put in one place. As with anything, your mileage may vary, but from my research, this is what I've gathered:

This may also be known as a compression or push start. On an EFI bike, you MIGHT be able to bump start succesfully, but not guaranteed. Why the doubt? Well, you still need a battery that has some charge to it.

When the ignition key is turned on, the ECU, and it's various sensors get energized, the headlight and tail light comes on, and the fuel pump primes the fuel system. To do this it takes an 8.5 amp load from the battery. Once the fuel pump has stopped, and the fuel system is at prime, the electrical load is reduced to 5.64 amps. So, your battery can't be completely dead or you'll be calling for help.

Assuming that the battery has enough strength to actually get to priming the fuel system, you can try and bump start the bike. It's pretty much a no-win if the battery is too weak to prime the fuel system. Keep in mind that the headlight and tail light is contributing to a constant current draw. Normally, when the starter button is used, the headlight will cut-out while the engine is cranking. This isn't the case here.

The art of bump-starting a bike is pretty simple.

1. Make sure that you have fuel
2. Ensure that the Kill Switch is in the RUN position
3. Put the transmission in a taller gear like third
4. Pull the fast idle control (choke knob) to the first position unless the motor is hot
5. Turn on the ignition, and hold in the clutch
6. Go for it! Either have some buddies pushing you or go down a hill
7. When you get up to at least 15 km/h (10 mph), quickly release the clutch. Beware of the back wheel locking up, and if the engine doesn't turn over or start, be ready to pull in the clutch to maintain control.
8. If its your lucky day, and the engine fires, apply throttle and pull in the clutch
9. The engine may want to stall as the stator/alternator is pulling a big load trying to charge the battery, so keep the throttle going.
10. It can take approximately 20 minutes to get the battery charged to the point that the bike can idle on its own. Please note that the battery is NOT fully charged at this point and shutting down the engine may repeat a no-start situation.
11. Go for a LONG ride (with backup friends, and/or cell phone) or put the bike on a proper charger.

For those that think that you could generate enough electrical power by simply bump starting the bike to cause the fuel pump to work would be extremely dangerous and the ECU, relays and fuel pump need a constant source of power.

The battery on these EFI bikes needs to have a voltage of more than 12.6 volts to start. Some bikes have required nearly 13.0 volts. Take care of your battery.

You can go around the low battery cut out by shorting the two terminals on the starter solenoid that lives behind the RH side cover. This would work if your battery may be strong enough to prime the fuel system, but be below 12.6 volts. NOTE: that by doing doing, all safety controls are also bypassed . So. kickstand switch, clutch switch, neutral switch, etc are bypassed, so make sure the bike is in neutral first!

Here's a picture of the starter solenoid. Bridging the two terminals with the red arrows will enable the bike to start.



H.

You are sure providing some useful information lately! Nice write up!!

Thanks, Keith

H.

Have been reading your posts with interest Hyates. Has made me a tad nervous having a EFI model. Look after my battery fairly well but after all your info will be making sure that it is kept right up to speed.
Cheers and thanks for the research that you done!

Thanks, I'm glad people are getting informed. I wouldn't be nervous, just be aware Yeah, I know, semantics! But, really, it's just being aware of how your bike is used (city, highway, short trips), and how often it's used, and take the appropriate action in charging it.

I typically only put the bike on the charger if I know it's going to sit for a week or more. My daily trips to work are mostly highway for over 30 km, so it doesn't need daily charging.

If you have a pigtail coming from your battery for your charger, you can put voltmeter leads there and read the battery voltage yourself. It's a quick way to get a 'feel' of the rate of discharge for the riding that you're doing.

Let the battery stabilize for 30 minutes after running or charging before you measure the voltage.

HTH,
H.

Bump starting Triumph EFI bikes is not generally very productive.
The exception might be when the battery has a decent charge, but the issue is the starter interlock from ECM is inhibiting the starter.
(in that case do the 'paper-clip' jumper per this post to bypass the ECM interlock to use the starter)

If battery is truly discharged however you are quite up against it;
the first & main issue is that the ignition needs to be on and thus headlights already sucking whatever power is left in the battery and even robbing any generated current as the engine begins to turn the crank during the attempted bump start. With a 'normal' start, the headlights are cut by the same relay that transfers power to the starter soleonid; this does not happen with a bump start and the headlights will remain on.
So - to give yourself a fighting chance, you need to inhibit the headlights before you even begin.
Simplest way to do that is to remove Fuse 9 - this would also inhibit your normal Start button, however since you are not using that anyway, it's OK to pull it for bump start. Once started (if you're lucky!) you can always re-insert the fuse to get your headlight back.

As a post-script with reference to this part:

Quote:

---

Bridging the two terminals with the red arrows will enable the bike to start....

---

That will involve pulling ALL the starter current through your shorting device (screwdriver or whatever is what is typically used!) - that will generate significant arc!
If I might offer a slight modification to that process, a much gentler approach is to 'short' the large input battery power terminal to the small coil terminal - this will close the solenoid and pass the power internally to the output terminal - difference is you are 'shorting' few hundred mA with your shorting tool, vs 80A or so between the high current terminals.
Again however, if you can access the starter relay, then pull that out & bridge between the two terminals with the white/red wires with a paper-clip and use the start button as per link above.

It's been awesome for D'Ecosse to clarify some of these posts.

However, please note, that my 2010 Speedmaster did not have the lights on a separate fuse. The headlight uses one of the engine 30 amp fuses. You have to physically unplug the headlight from the wiring.

H.

I've had SERIOUS problems with the 09 this winter. Due to the short distance to work I've not been getting enough charge back in to the battery so it's been going flat (I never had the problem with either of the carb'ed bikes....so assuming it's due to the extra charge requirement of the efi and the pump). I have a spare battery at home now, and it's kept charged just in case...

So how to jump start it just in case is handy to know.

And I have started the 06 using the short-out-the-solenoid method...it sparks nicely!