Subaru EX21FI

[Az Shadeguy]

Subaru EX21FI
I have a ridged power washer that has Subaru engine with fuel injection.
It will not run. It will run for a few seconds if I prime it.
It has a pulse pump on the bottom of the throttle body that leaks.
These throttle bodies or parts are no longer available.
Could I just put a regular carb for a ex21 on it?
I know I would have to seal of the gas return line on the tank.
I can buy a complete used engine Ex21FI on ebay for less than the price of a new carb. But it also has fuel injection

[bgsengine]

sounds like you might need the diagnostic software and cable - this is the only place I can find a picture of it . http://www.ebay.com/itm/987190001-Subar ... 1465808159

[bgsengine]

Other than that - I have only ever had 2 of these in the shop for repairs and neither for engine work... (both were in for warranty service for the pressure washer part of it) have not even had a chance to try out the diagnostic software.. However I dont know as it can be changed to carbureted model without also changing your ignition system too...

[KE4AVB]

Unless the engine setup is different than from what I see in the service and part manuals I downloaded you don't need to change the ignition system as it is a simple magneto ignition with only a kill output control from fuel injection system. You would lose low oil shutdown; unless, rewired. The change over would require a new throttle control assy or at least the part numbers are different (probably because of temperature sensor) in addition the new carburetor. You also need to cap off the impulse line as you won't need it for carburetor.

The ECU does receives signals from oil, speed (power coil), and temperature sensors which regulates the injector fuel flow for correct air/fuel ratio. A very basic fuel injection setup. Look like the ECU is picking the rpm from the pulses from the power coil.

To me it looks like an easy conversion; although, it not easy on the wallet. Used carburetor and others parts should be obtainable which would help with the costs.

[Az Shadeguy]

Thanks for the help.
I think I will order a carb and see what happens.
I will report back

[Az Shadeguy]

Okay so I finally got this back together
New carb plugged the ports with vacuum caps
Pulled out the extra wires
It started right up and surges like all get out.
The linkage seems to be the same on the efi or carb engines
Any thoughts

[KE4AVB]

Have you tried add a little choke to see if it smooths out. If does then the carburetor is too lean. If it don't then you may need to redo the static governor adjustment.

[Az Shadeguy]

Okay thanks the carb did not come with a choke lever
I ordered one it will be here next week.
I think I can move it by hand so I will try that and a static adjustment
Thanks

[Az Shadeguy]

Well half choke does not help. The static governor adjustment did not help either
Any other suggestions?

[bajadudes]

Hello all,

My first post. I am reviving this thread in the hopes that additional info might aid anyone attempting a conversion of the Subaru EX21 F1 engine EFI throttle body fuel delivery to standard carbureted delivery.

After a lot of research and talking to the Rigid power tools parts division I decided to order this version off of Amazon

"New Carburetor Subaru Robin EX21 GENUINE Mikuni 278-62301-30"

It should arrive in two days and I will try it out over the weekend and update this thread.

Nice site BTW.