Honda CT90 Engine Reassembly

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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...
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More 3D Printed Parts for Use on Honda CT90 & CT200 - Hard to Find K1 Parts and Others

I'm continuing to find and endless number of opportunities to utilize my 3D printer to make useful parts for my CT90 project bikes, my fishing float tube, and other hobbies that I have.  I thought I would share a few of the latest CT90 parts that I have designed/modeled and printed.

All of the designs I share below, I first modeled using my ViaCad 2D/3D modeling program.

Related Posts:

A New Batch of Honda CT90 and CT200 3D Printed Parts

More 3D Printed Honda CT90 Part Designs

3D Printed CT90 K1 Rear Airbox Snorkel

CT90 K1 3D Printed Carb to Air Filter Boot

A 3D Printed Valve Spring Compression Tool


CT90 K1 Front Fork Cover Side Reflector Base

On almost every older CT90 I work on (I guess they are all old...) the little rubber caps on that cover and help hold in the bulbs on the base of the speedo are cracked, disintegrating before my eyes or are just missing.

I modeled up both a short cap that has a hole for one wire and a taller cap that has a slot in its base that allows two wires to pass through as shown in the pictures below.




When I modeled the reflector base I took into account the taper of the fork cover and added a small raised dot for the end of the reflector base that should point up.  The 3D printed part is on the left in the picture above and the stock Honda part is on the right.


I printed these reflector bases using SainSmart TPU and PETG and I think that both materials work well for this application. 

Here is the link to the .stl files at Prusaprints for the reflector base.


CT90 K1 Upper Triple Tree Turn Signal Mounting Hole Plugs

Someone had asked after I did an earlier post on plugs I had made for the rear fender for the turn signal holes if I could make plugs for the turn signal mounting holes in the CT90 K1 upper triple tree, so I did and here they are. That are similar to the original plugs and will functionally fill the holes.  

I made the design of the features that fit into the holes slightly different than the original Honda plug designs as I printed these parts using SainSmart TPU which is significantly stiffer, but again still functional.

I have included links to .stl files below, but if you don't have a 3d printer I also sell a set of these plugs on eBay here at this link.






Here is the link to the .stl file at Prusaprints for the plug.


CT200 and CT90 K0 & K1 Battery Compartment Bumper

I've noticed on some of my older K0 & K1 CT90's and also on my CT200's that they have a round bumper on the back wall of the battery compartment.  I still had one of these rubber bumpers so I decided to create a model of the part so that I could print copies on my 3D printer.

Here is a shot of the original bumper.


Here is a shot of the part I modeled and then printed next to the original rubber bumper.


Here is the 3D printed bumper printed in TPU installed is a CT200 frame


Because the TPU is not near as stretchy as rubber, it is a little tough pulling the stub of the bumper through the hole in the frame, but with a little grease, twisting and the help of a small screwdriver, the bumper was installed.  Using a lower durometer filament would make this part easier to install.

Here is the link to the .stl file at Thingiverse

Here is the link to the .stl file at Prusaprinters


CT90 K1 Front Fender Reflector Holder - A Work in Progress

I've been working off and on on this part as I have been finding it difficult to come up with a model of this part that prints well.  

In the picture below the stock reflector holder with the metal band is on the left and the three on the right are different 3D printed designs I have tried with varying degrees of success.  The two right most designs are made from PETG and have a split on the lower edge to allow for installation of the reflector.  The one 3D printed design in the lower center with the reflector installed is made from TPU and the reflector snaps into place.

In the end I think I will have a design that is almost identical to the stock part in that it will accept the metal band that wraps around the stock reflector holder. I also think I will have an all plastic design out of TPU or PETG that won't use the metal band.

I'll update this post in the future when I get a final design I like figured out.



I hope you found this information useful.


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


Comments

  1. UnknownJuly 6, 2021 at 12:23 AM

    Very much thanks i would like to buy when your final design is complete thanks

    ReplyDelete

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