Land Speed Racing

[HondaJohn]

So.....this happened! The KZ400 is in print! Cafe Racer Magazine October/November issue

[coachgeo]

Sweet..... it is much sweeter when someone not trying nor wanting fame at all..... gets a little of it.

[HondaJohn]

Many of you have asked me about the reliability of my Yanmar clone after all of the modifications that I made. I can now answer that. After 7 years of development, as well as:

-4 certified land speed records
-2500 miles of riding.
-Disabled speed governor
-Supercharged to 5psi
-Upgraded valve springs

...the crankcase split in half directly below the cylinder, nearly blowing the top end clear off...

RIP to the first engine, and time to start looking for a new Yanmar L70 clone. Onward and upward!

[HondaJohn]

After careful examination, I am confident that the guts of the engine are fine, and the damage was limited to the crankcase. So, rather than simply swap engines, I've decided to purchase a replacement crankcase and transplant as much as possible out of the blown motor

(yes I'm aware this is the more difficult option, but I'm stubborn )

I registered an account with AliExpress, and hopefully I will be in possession of a fresh crankcase within the month

[HondaJohn]

It has arrived

[pietenpol2002]

Wow! That's amazing to have it from China in 2 weeks. Good luck John. And keep us posted on the progress.

[coachgeo]

John have you considered the need for storing some air from blower like is recommended for turbo charging to see if this helps? 2014 study said 5x the engine capacity..... another person in here did ok with 3x. See last couple post in below thread to info on reasons.

https://www.dieselbikeforum.com/view ... f=32&t=962

[HondaJohn]

I finally worked through my backlog of other projects, and the KZ400 diesel is now back on the bench for a rebuild. The first step was to disassemble the drivetrain, clean the frame, and improve some of the mounting hardware and wiring.

[HondaJohn]

I finished stripping the engine, and was able to examine the inner assembly for the first time. Overall, the components are in excellent condition, the only major issues being excessive carbon buildup in the combustion chamber, and wear on the output-side plain bearing.

I also inspected the camshaft, and found no evidence that the stronger valve springs had caused any damage to the lobes.

[HondaJohn]

Progress! I've refurbished the original engine internals, deburred the new crankcase, and installed everything with fresh bearings and seals.

[HondaJohn]

Engine reassembled and tuned!

[HondaJohn]

I brewed up some caffeine and locked myself in the garage for a marathon reassembly session last night

[HondaJohn]

Finished reassembly and received a fresh NYS inspection. Finally ready to ride again!