XR500 Diesel Bike Farymann 43F

[pietenpol2002]

Congrats on a remarkable achievement. Both for meeting your goal and winning the bet, but also that you did so with a very unconventional approach to a diesel bike build. I commend you also for identifying early on the areas needing attention and now the fun of conquering them each as a part of the refinement process. And finally, I hope by now you've caught up on your sleep.

[focodiesel]

Congrats on a remarkable achievement. Both for meeting your goal and winning the bet, but also that you did so with a very unconventional approach to a diesel bike build. I commend you also for identifying early on the areas needing attention and now the fun of conquering them each as a part of the refinement process. And finally, I hope by now you've caught up on your sleep.

Thank you for your compliments, I knew I wanted to use this engine, and the xr500 parts to create a bike...The rest was a whole lot of staring at the parts, Drawing lots of design sketches, and researching for parts that would work. The project has evolved through the process as do all projects. Originally I was thinking of trying to use the stock Honda transmission, due to uncertainty of feasibility of this I decided to go with the harley transmission, and I'm happy I did. Also, in the early stages of the build I was planning on mounting the engine above the transmission. Thanks to some healthy criticism on this site, I started pondering flipping the design to have the trans on top, again, this worked well, keeps the weight low, I was able to keep the top portion of the frame and the stock gas tank/seat.

[coachgeo]

....decided to go with the harley transmission, and I'm happy I did. Also, in the early stages of the build I was planning on mounting the engine above the transmission. Thanks to some healthy criticism on this site, I started pondering flipping the design to have the trans on top, again, this worked well, keeps the weight low, I was able to keep the top portion of the frame and the stock gas tank/seat.

Im curious to see where chain and sprockets lie with your high transmission. Just wondering how you did it? Assume you used an extra chain dropping down from Tranny to spin the two typical sprockets of a motorcycle that allow for movement of chain along same arch of rear swing arm.

[focodiesel]

Im curious to see where chain and sprockets lie with your high transmission. Just wondering how you did it? Assume you used an extra chain dropping down from Tranny to spin the two typical sprockets of a motorcycle that allow for movement of chain along same arch of rear swing arm.

Not exactly, I moved the swing-arm bolt location higher to keep the drive sprocket in line with the rear wheel axle. I have a chain driving a cone clutch on a jack-shaft above the engine in front, then the output of the clutch (v-belt for now) runs to the transmission input shaft, which I had to cut off shorter and mill a key-way into it. I will post some more detailed images as soon as I can.

[focodiesel]

[coachgeo]

ahhhhh... see what you've done there better now. The layout of that diesel does make for a neat package.

[garett0439]

Awesome build man, now that is a machine!
I am going to use this engine/ trans combination on my diesel bike build.
I found the farymann 43f's for 550$ used!
I have a couple of questions-
Have you got a stator going yet? I plan to use a flywheel&stator from the dirtbike junkyard and mount the flywheel onto the output shaft and somehow mount the stator stationary inside it around the shaft. But, I don't have the engine in front of me yet so these could be just pipe dreams.
How common/cheap are the harley transmissions? Is that what I should use?
My aim is purely towards economy- as many MPG as possible, I can sacrifice wheelbase and width to make things fit. I would like to use the clutch off of the harley trans. How much wider is it, and is that the only reason why you didn't use it?

[garett0439]

I am building solely for the purpose of traversing statewide distances while towing my bike, to save as much money as I can. That is why I think I would need the strong and reliable harley clutch. What are your guys thoughts?
Check out the attachment-that guy is my hero!

[garett0439]

Oh and by the way, sorry to hijack your thread... keep the pictures coming! And we have been waiting a while for your next video as well!

[focodiesel]

Awesome build man, now that is a machine!
I am going to use this engine/ trans combination on my diesel bike build.
I found the farymann 43f's for 550$ used!
I have a couple of questions-
Have you got a stator going yet? I plan to use a flywheel&stator from the dirtbike junkyard and mount the flywheel onto the output shaft and somehow mount the stator stationary inside it around the shaft. But, I don't have the engine in front of me yet so these could be just pipe dreams.
How common/cheap are the harley transmissions? Is that what I should use?
My aim is purely towards economy- as many MPG as possible, I can sacrifice wheelbase and width to make things fit. I would like to use the clutch off of the harley trans. How much wider is it, and is that the only reason why you didn't use it?

The farymann 43f is a wonderful engine congrats on finding one for $550, The downsides to it (for a motorcycle) are that it has a massive flywheel, it has no manual decompression lever (automatic decompression based on rpm), it is somewhat rare compared to yanmars/clones, most come with 24v starters and it is a horizontal engine-which means getting creative to fit in a motorcycle, like I did, stacking the trans over-head (no pun) or super-stretch the frame. I like them because they are slow speed (3000rpm max), undersquare, direct injected, German design/made, a good size (700cc), and relatively light 100lbs. They only put out 15hp at max rpm, which as mentioned before in this thread should limit top speed to about 60 mph, I have not tested this as I need to lower my gearing, way too tall initially.

As for stator, My engine did not come with a stator either, this is because they were military mep units which drove a 28v dc generator, hence the 24v starter. Farymann was or is owned by Briggs and Stratton. After removing the Flywheel there is 4 cast bosses in the crank bearing plate, mine were not drilled and tapped yet I assume yours wont be either. I had a hunch that a B&S stator would line up with these bosses, after ordering a B&S stator, I can confirm the four mounting points are the same, so I will be drilling and tapping the holes to mount the stator under the flywheel, and the more tricky part will be mounting the magnets onto the farymann flywheel I havent quite worked that out yet. When I do that I will post it up. Of course if money is no object the easier solution would be to contact a farymann dealer and buy a crankbearing plate, with the stator, and a flywheel with the factory magnet setup, I just assume that would be incredibly expensive that is why I am using B&S parts.

The reason I modified the harley shaft and did the clutch the way I did was mainly for width reasons, yes the stock harley trans/clutch is very wide, but it all depends on your seat position, if it will be like a harley cruiser style position, than the clutch will stick out behind your left leg, no prob. If you use the harley clutch they are wet, and therefore you would have to build a custom primary cover to seal it up. I used the harley trans because it is cheap ($800 shipped I believe) , new, six speed, strong, correct side shafts, and huge aftermarket support, just do an ebay search and you can many vendors selling them.

Hope that helps.

-Focodiesel

[focodiesel]

FYI, I have added a list of my build videos with links on my first post.

[gearhead1951]

A "wet" clutch is wet because of the perceived need for running the chain in an oil bath , If you don't see the need for the oil bath (running a belt or just letting the chain run dry ) Then the clutch will operate actually better than if oil soaked !