Without going into a long backstory, I had a custom ‘85 K100 built a couple years back. The custom work was very well done, but the bike engine was very high and now I find myself needing to replace the engine because it would need a complete rebuild and I happen to have a low-mile K1100 parts bike I can use.

I’ve never done an engine swap and looking for any knowledge, wisdom, or key content to reference (video, blog, notes on a napkin) before I do anything else.

Will I need other/special parts to accomplish this and if so what are they and or where do I learn what they are.

Any help guidance, direction would be a life saver. I have been unable to go for a ride in over a year and my soul is dying.

Thank you

Thomas

You are going to need a lot of wiring [I suggest you get the K1100 loom as well] as there are many subtle differences. The 85 K has an ignition control unit and a fuel injection control unit. The 16v engines have a single motronic unit. You could swap in the complete intake side, motronic unit, injectors etc but you should have all those.

The extent of all this is going to dend on what your custom K100 is like so you need to pop up some information on this.

You will have to make some modifications on the fuel tank side as the connectors etc differ if you have a bolted on fuel tank found on the early 85 K100.

Your clocks will differ.

As an aside you can swap the engine, gearbox and complete drive train with the rear disc, caliper, shock, stand assembly, intakes, air box, etc etc! Or just the engine.

Watch out for engine mountings and shims.

tjh1985 wrote:I find myself needing to replace the engine because it would need a complete rebuild . . .

Without going into a long backstory, what's wrong with the 2V engine—crank, piston, valve or bearing failure; hole in the case?

Olaf has pretty much laid out the challenges facing you. The two bikes' frames differ so measuring and comparing mounting points and clearances is essential unless a hero who has done this conversion appears, cape and all, to deliver the specs; however, verify that the hero isn't a precocious 13-year old hypothesizing from a backyard treehouse via wi-fi.

92KK 84WW Olaf wrote:You are going to need a lot of wiring [I suggest you get the K1100 loom as well] as there are many subtle differences. The 85 K has an ignition control unit and a fuel injection control unit. The 16v engines have a single motronic unit. You could swap in the complete intake side, motronic unit, injectors etc but you should have all those.

The extent of all this is going to dend on what your custom K100 is like so you need to pop up some information on this.

You will have to make some modifications on the fuel tank side as the connectors etc differ if you have a bolted on fuel tank found on the early 85 K100.

Your clocks will differ.

As an aside you can swap the engine, gearbox and complete drive train with the rear disc, caliper, shock, stand assembly, intakes, air box, etc etc! Or just the engine.

Watch out for engine mountings and shims.

here is the good question: what the references point are? My experience tells me that engine should be right that means shims have to stay with the frame.

The flat plate at the bottom of the oil sump can be swapped. It is my understanding that the box part of the oil sump is matched at the factory to the engine block - which is why it is not sold as a separate part.