Found a local guy on CL selling an engine from a wrecked GSF.  I would like to transplant this engine into my 97 GS500E due to my current engine making terrible knocking noises.  What issues will I run into with using the newer engine?  So far I know I will have to find a way to mount the external oil cooler and do something with the tach.  Will the mounting holes line up?

My current engine is not worth rebuilding.  I'd rather spend ~$250 to get the replacement engine and be done with the bike.

Engine ID is M504-12304.  What year is this engine?

#5004

You can use the 2004 engine. Things you will need to do:

1. Use the intake manifolds you have. The older carbs need that manifold as it is slightly deeper. Replace the o-rings when you move them from old to new engine.

2. Move your timing rotor and pickups to the new motor. New bikes had a single pickup not compatible with 1989-2000 wiring.

3. You will lose the mechanical tachometer. You can swap heads to keep it or get an electronic tach and wire the signal to the input of one of the ignition coils. New heads do not have the gear for the tach cable.

4. You will need to mount the oil cooler. That's easy to do especially if you get the bracket from the crashed bike.

The motors fit exactly the same. I put a 2006 motor into a 1993 frame. however I used the newer carbs and rewired the bike with the 2006 wiring so I did not have to change the timing pickup. I also put in electronic tach as that worked with the 2006 wiring. Rewiring a bike with 2006+ wiring is easy. It does require you to replace your hand controls, too, as the connectors are different.

Thanks for the info adidasguy!

I know the tach on my 97 is driven by a worm gear on the exhaust cam which the 04 doesn't have.  Can I switch the exhaust cam from my 97 into the 04 along with the 97 valve cover or do I need to move the entire valve train including the cylinders?

#5007

The head of the 2004 does not have the hole for the tach cable. Swapping the cam shaft would be pointless since there is no way to get the tach cable to it.

You would need to swap the entire head. (Or the tach)