KDX 200 engine rebuild

Building a KDX 220 hybrid engine HERE.

Apparently I can screw up a simple 2 stroke pressure test. After riding around the yard for the initial Rekluse EXP testing, this is what dripped out of the silencer:

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I pulled off the pipe and let it site upside down for a little bit and this is what came out:

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With the jets I’m running, this much oil can’t be from the carb being jetted too rich. Time to rebuild the engine.

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Day 1 – Engine removal

After an hour and 15 minutes, this is where I’m at:

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Day 2 – teardown

Yes – everything is dirty. If I weren’t doing a complete rebuild, I would have spent some time cleaning the bike up before taking it apart.

Jamming a soft metal, like aluminum or a penny, is the easiest way (that is if you don’t have a impact gun) to lock the engine so you can loosen the flywheel, crank and clutch nuts.

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I noticed that my crank was not centered at all. It was shifted towards the clutch side by quite a bit:

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Clutch side:

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Flywheel side:

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The crank on the junk motor was better, but still not perfectly centered:

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Flywheel side seal was leaking and there was some play in the clutch side crank bearing. Looks like I was overdue for a rebuild:

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And just like magic the crank is free. There was some areas with surface rust. I noticed that several years ago when I did a topend on the engine. Previous owner must have got some water in the engine and didn’t dry it out. I’m also sending the crank out of the junk engine to the rebuilder so he can decide which crank is the best for the rebuild.

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The end of day 2:

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I wish I knew how much of this was related to the Lucas pre-mix or burning ATF:

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Day 3 – Cleaning

I used a variety of methods to clean all the parts, it really depended on how dirty they were. The cases sat in diesel for a while:

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Then sat for a while with Shout on them:

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And finally they got cleaned with this:

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Most other parts got cleaned in old pre-mix. Everything all cleaned and stored in the basement:

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I also cleaned up the cylinder head. KIPS main valve before:

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KIPS main valve after:

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Then assembled the KIPS.

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End of Day 3:

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Day 4

All I got done today was install all the bearings, except the left crank bearing, and a few other small pieces:

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Day 5

Got the cases put together today. Pulling the crank into the right / clutch side bearing:

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Something I did a little differently was to leave out the bearing on the left / flywheel side. This allowed me to bolt the left / flywheel side case to the other side so that I could check the centering of the crank and make sure the transmission was installed correctly:

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Still not centered:

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Once everything checked out, cleaned the mating surfaces, applied the Yamabond and then pulled the crank into the left / flywheel side case. This is where I’ve left things:

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Things on hold due to this and this.

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Day 6

With the crank back from RB Designs, time to put the cases back together – AGAIN.

Starting with new crank seals and bearings:

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Bearings and seals installed:

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Getting it all back together:

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Day 7

Several project have gotten in the way of making progress on this, but I had a chance to work on the engine today. Got the piston installed. Wiseco calls for a minimum of .01 ring end gap. Both of mine were .014, so no need for filing.