Honda CT90 Engine Reassembly

Image
I have one 1971 CT90 where I was going to rebuild the clutch because the kickstarter just wasn't turning over the engine like it used too,  and I also had a Big Bore kit from DrATV that I wanted to install. My intent was to just do the top end and rebuild the clutch with new disks, but when I opened up the cases to rebuild the clutch pack I found a slick black slime in the bottom of the case.  I didn't like the idea that there could be black slime in the rest of the engine, so I decided to disassemble the entire engine to make sure I cleaned everything out.  Since I was tearing everything apart I thought I would document step by step how everything goes back together in this post in case others were interested in knowing what the inner workings of a CT90 engine look like. Links to Related Posts: My Honda CT90 Clutch and Headset Nut Tool Cut Away of a CT90 Engine - CT90 Engine Exposed! Repairing Damaged CT90 Spark Plug Threads Using a Time-Sert Thread Insert CT90 Cl...

Essential Oils for Working on Your CT90 Project

The picture below are the three penetrating oils/lubricants that I keep handy when restoring an old CT90.





When I am first tearing down a CT90 I like to completely disassemble the area I am working on to see what I am up against and much of the time the bike doesn't want to come apart due to corrosion or oxidation, so I turn to my three favorites WD-40, CRC Power Lube and Kroil.

I use the WD-40 as my low end penetrating oil and as a general lubricant. In general it does a good job and is relatively cheap.

When things get more serious I usually turn to the CRC Power Lube as I think it work better than WD-40 both as a penetrating oil and as a lubricant and is my favorite all around spray lubricant.

When I am faced with potentially breaking off a screw that I can't afford to have break off or some other critical application where I really need all the help I can from a penetrating oil I turn to the Kroil. While not cheap or as readily available as WD-40 or CRC Power Lube, nothing comes close to Kroil from a penetrating oil perspective and it can be worth its weight in gold when you need to free up a corroded in screw. Just apply a few drops and let set overnight and Kroil finds its way down into just about any threaded joint and really helps free up difficult screws.


Helpful Links (Shop Manuals, Wire Diagram, Model Information, etc.)

Comments