Forum

[vill98]

Has anyone done the carb conversion on there efi and what was the results

[RayBeech]

Yep, I did. I had gone the PCV route but an too old/not interested in computers so never really got it set up right, so I bit the bullet and took all the fuel injection off and replaced it with Hitchcocks mk1 concentric kit. The bike now runs a treat - no stuttering (which I found very disconcerting mid corner if you hit a bump and your hand moved the throttle slightly) The only thing that needs getting used to is the ammount of time to leave the choke on but that is the same with any machine. Basically I am very happy with mine.

Ray

[Jerseyplym]

Out of interest, how does the ignition work with the Carb kit?

[RayBeech]

There is just a small plug that fits into the injector connector and the ingition becomes , well, just electronic ignition. The old kit that Hitchcocks supplied came with a lot of extra bits, new ignition unit flywheel etc. for the ingition, but now the kit is a couple of hundred quid cheaper and only needs the supplied plug to work perfectly. I Emailed them and they explained that a lot of work had gone into developing the system so I assume the plug (which is about the size of a sugar cube) has some electronics inside it to adapt the original ignition mapping.

Ray

[jefrs]

If the kit had been available when I went down the PCV rabbit hole, I too would have given the carb conversion serious consideration. I did look into it but only found systems involving swapping out the alternator and sensors etc etc then; too complicated. I found the (oem ecu) either on or off, all or nothing, stuttering of the injector amid a slow corner/tight bend to be disquieting (actually the ditch is more worrying), and although the PCV helps, the 0% and 2% columns of the Fuel Table are not mapped (default ECU values there, closed loop). It can be fixed, I am gradually fixing it, but it is a lot more complicated with laptop and tables of numbers doing your head in than playing with jets and needle tuning a carb. You can probably get more power and torque out of the injector but you may well make it run better with a carb. What you can't do with the carb kit is alter the ignition table like you can with the PCV.

[jefrs]

There are three connections to the injector and throttle body. The Throttle Position (TPS), the Air Pressure (APS, MAP-like but not) , and the Injector itself. Is the entire throttle body removed? The ECU uses the throttle body TPS to alter the ignition A/R as well as injector pulse duration, does one lose the auto- (acceleration/deceleration) advance/retard and only use engine rpm speed? What happens there with the kit, the injector gets a dongle but the other two are left unterminated?

[RayBeech]

Hi Jefrs, yes the whole lot comes off, there is a manifold extension/adaptor to fit the carb and a K&N type filter that fits neatly into the remaining space before the airbox. The oxygen sensor was already removed from the Exhaust as I had fitted our hosts free flowing item with a gold star pattern "silencer" and the other plugs are, as you suggest just left disconnected and tie wrapped up under the rear of the Tank. Also I removed all the original filter and stuff, put a round blanking plate over the hole in the rear of the airbox and use it to keep extra tools and bits and bobs in.

[enfield_trials]

Check this out ..

royal enfield 500 classic efi 2012 kit conversion injection carburateur.avi

https://youtu.be/m_z1L3HeESQ

[jefrs]

enfield_trials - that is one of the videos I watched that put me off going to carb conversion, the modifications to the engine are quite extensive. See around 5:00 there is a blur of tools and the engine is in bits. Doable but well complicated.

[jefrs]

RayBeech - I can see from the PCV data on the laptop that the oem ecu uses the throttle position and the engine rpm speed to not only control the injector pulse duration but also the ignition advance/retard. By removing the TPS on the carb conversion how then does the ecu control the A/R, on the engine rpm speed alone or does it go to static timing, and if so how does one adjust it?