# BMW conversion,

### Help Support Homebuilt Aircraft & Kit Plane Forum:

#### WindHorseRookie

##### Well-Known Member
Can we revive the BMW conversion engine threads?
I am just curious, what is the best parts combination and where to find them ?

Engine
PRSU
Exhaust
Intake box
Harness ECU

for application let’s say a Kitfox.

#### WindHorseRookie

##### Well-Known Member
I have found a 2011 R1200 for a decent price with harness ECU starter maybe some misc parts.
I know I’ll have to make the intake box and exhaust.
what would have to be done to the harness and ECU?
will a Rotax E gearbox work on this.
I am searching the web, not finding anything definitive.

#### Will Aldridge

##### Well-Known Member
Log Member
I have found a 2011 R1200 for a decent price with harness ECU starter maybe some misc parts.
I know I’ll have to make the intake box and exhaust.
what would have to be done to the harness and ECU?
will a Rotax E gearbox work on this.
I am searching the web, not finding anything definitive.
I'm not an electrical engineer so honestly don't know the ins and outs of what this means, but when BMW went from the R1150 to the R1200 they made it a CAN bus control system that makes it unsuitable for aircraft as a single fault is enough to shut everything down. Not what you want in an airplane. It is generally agreed that you can preform surgery on a R1150 wiring harness and ecu and have it be fairly reliable, but it doesn't work on the r1200

#### WindHorseRookie

##### Well-Known Member
I'm not an electrical engineer so honestly don't know the ins and outs of what this means, but when BMW went from the R1150 to the R1200 they made it a CAN bus control system that makes it unsuitable for aircraft as a single fault is enough to shut everything down. Not what you want in an airplane. It is generally agreed that you can preform surgery on a R1150 wiring harness and ecu and have it be fairly reliable, but it doesn't work on the r1200
Thank you for that, I will keep searching for the parts.
sounds like I need to find a different bike for a donor.

#### Bart

##### Well-Known Member
How much (if any) of the computer control and wiring harness from an 1150 or 1100 engine would plug and play into the 1200 engine?

I have an 1150 engine, as well as a running 1100 bike, plus a fair amount of experience working on old BMW car of the late-80s to mid-90s vintage, and have found there to be a fair amount of plug&play between various BMW products. From this, I suspect there may be potential for 1100 wiring harness/computer control to be used on the 1200.

If my suspicion is verified, this may be a way to use a proven reliable 1100 electronic control system while taking advantage of the lighter weight and greater power of a 1200 engine.

#### zibi

##### New Member
And what about a redundanty CAN-BUS ?

#### bodex

##### Member
I'm converting a 2006 1200RT engine ATM, I was going to use speeduino which is a DIY EFI brain that can run just about anything. However my 19 reg single seat is simple and the added systems of injector pumps etc have got me looking at a pair of mikuni carbs to slot into the injector bodies. For the psru I purchased the air trikes adaptor from Canada and adapted a C Rotax gearbox. Unfortunately this is to long for my cowl so I adapted a 10mm alloy plate onto the front which holds the gearbox and the drive comes from an alloy disc that bolts to the starter ring gear. Exhaust will remain mostly stock with a shorter muffler, rumour is the balance tube is important on BMW twins.

A good gallery here of someone's conversion..

If anyone wants to buy the air trikes adaptor let me know. Number in picture...

#### turbolium

##### Member
Grab the exhaust headers as well, need those.
For the wiring I would go with Take off wiring harness, for $300 euros cant go wrong. Prsu you have some options, if your a bit handy you can just use a rotax c with a built in clutch and starter and just make an adapter plate for the engine, or bolt on a kit which will run you about$3000 theres a few companys that make them.
But to get more info you have to check the euro sites, these guys have been flying these engines for the past 20 years.

#### Air Trikes

##### Well-Known Member
Are you sure Takeoff harness is 300 euro? Yes, I have built BMW R1150 with flat plate adapter but it was 2.5 ratio SPG-3 gearbox and light carbon prop. I don't think this variant will work for R1200 and 3.0 ratio Rotax C box.

#### Attachments

• 84.7 KB Views: 17
• 73 KB Views: 17

#### Bill-Higdon

##### Well-Known Member
I have some documentation on the 1000 including electrical, but I doubt it would work on a 1200

Last edited: