Ignition coils

Aprilia Futura – Coil failure and replacement

Ignition coils on the Aprilia RST Futura have been known to fail, particularly in the UK where salt is used to treat icy roads.

The four coils are integral to the HT leads and like the ECU, are made by French electronics company Sagem.

Some riders have got through a fair few coils. The rear pair of coils are also vulnerable in the event of a drive chain snapping.

Rough running and a lack of power is usually the first symptom of a coil breaking down. It may also only happen when the bike is fully warmed up, as the coils become hot in use and connections will break down due to corrosion. The Futura’s self diagnostics are pretty good at picking up a coil error and the EFI warning light will flash.

If this happens, put the bike in diagnostic mode and see what error codes come up. There’s an error code for each coil. See EFI error codes for a full list and how to put the bike in diagnostic mode.

Coil numbering and error codes

Coil #1
front cylinder – centre plug
wires – brn/red and orange/white
EFI code – 33

Coil #2
rear cylinder – centre plug
wires – brn/red and yellow/blue
EFI code – 34

Coil #3
front cylinder – side plug
wires – brn/red and gr/lt blue
EFI code – 35

Coil #4
rear cylinder – side plug
wires – brn/red and orange/lt blue
EFI code – 36

Coils are not repairable, and by all accounts they are a pain to get on and off. Once you’ve replaced the offending coil(s) the EFI light will stop flashing. If it doesn’t stop then you’ll need to go through the diagnostic process again.

Replacements

Aprilia’s replacements aren’t cheap, but owners have experimented with a couple of cheaper alternatives.

However, the coils are the same as those used in some fuel-injected Renaults (particularly the Clio and Megane), and with a little modification of the plastic casing, using your old coils, can be made to fit. Renault coils are generally cheaper than those Aprilia will sell you, and they are more widely available.

Some owners in the US have experimented with GSXR coils but I don’t have much information on this.

There are several aftermarket options in 2011. The latest info is available on the following thread on the Apriliaforum: Alternative coils

If you’re thinking of going the Renault route, be aware there have been some bad reports of Renault coils. Some swear by Renault, others who have tried them went back to Aprilia and paid the £80-odd each for OE replacements.

How to fit Renault coils

Here’s Ib12′s guide:

  • Remove sleeve on Renault coil. Mark on coil body with white marker where cap connector plug sits.
  • Remove cap – doesn’t matter if you destroy as it’s not needed.
  • Mark Aprilia coil cap where connector exits so you can marry up with the mark on Renault coil.
  • Using a ring spanner slide up the Aprilia body and whack the cap off, it will come off after a couple of whacks.
  • Cut Renault coil to same length as OEM (grey plastic bit at bottom).
  • Fit cap aligning pins with marks made earlier. I used silicon to seal it. I also cut down some of the spring from the Renault coil and put a self tapper in to make the connection with the HT lead. I also used a cable tie to hold the HT lead just in case.
  • It’s not a too difficult job. Takes longer to fit the damn things back on the bike.

There’s also plenty more information on this on the Apriliaforum: