CT90 Front Fork Rebuild and Install - Honda Trail 90 1971 K3

[@DevinGrigsby]

Came back to the video for another 90...almost a year later. Glad the video is still here. Very easy to follow and make sure done right. Appreciate it man!

[@bottomupbuilds]

glad it helped!

[@MsJhook]

really nice man

[@randyeasley8138]

A very nice informative video. The one thing that I noticed though that at 9:30 in the video when you installed the spring you had the coarse pitch of the spring up. The Honda manual says that the narrow pitch (the spring coils are closer together) should be up. Thank you for taking the time to make the video.

[@bottomupbuilds]

Good catch you are correct. I had it set up correctly prior to that point, but must have accidentally flipped it for the demonstration of sliding it down the dust cover.

[@magstrikefjerstad3192]

@@bottomupbuilds hey when you rebuilt the hi and low speed transmission did you put some type of grease in the casing?

[@bottomupbuilds]

@@magstrikefjerstad3192 no, grease would be bad. You can't really see it, but check the motor build video at 2:50 and you'll see a small hole just to the left of the gear selector shaft. I'm not sure if that hole supplies or drains the oil (or both maybe) from the crank case, but no additional oil is needed. Just fill the crank case as usual and oil will make it to the sub transmission.

[@magstrikefjerstad3192]

@@bottomupbuilds oh ok. Will do thanks

[@DevinGrigsby]

Great video! Thank you.

[@steveswann8448]

So what was your final decision on the rusty fork pistons? Did you clean up the rust (describe please) or replace with new?

[@bottomupbuilds]

@@steveswann8448 yes, the rust pitting was too bad. The seals wouldn't hold the oil so I had to get new forks. I order the heavy duty fork kit from dratv.com

[@opinion4246]

Thanks for viedo 👍

[@DaBombDotCom77]

MORE CT90

[@AshHalls]

Yes

[@gonearoundthebendPNW]

Are there washers behind the axle bolt and another behind the castle nut? I came out with an extra washer, but fear that if I install 2 of them I won't be able to install the cotter pin through the castle nut.I can't find an assembly parts diagram for my 74 k5 and all the videos I can find go to time lapse and make it impossible to see.

[@bottomupbuilds]

There should be a washer on both sides, on the outside of the forks.

[@kewkew2]

Couple of questions. Is that the original engine or aftermarket engine and I'm trying to figure out how you relocated the air filter. Thank you

[@bottomupbuilds]

It is the original engine. I did not have the factory air filter and intake that routes it up to the back rack, so I purcahsed a general use filter on Amazon or Ebay and just attached it directly to the carb.

[@AB-ku3fu]

Were your forks cleaned up re the pitting or do you just figure you will get a fair run out of the new seals.

[@bottomupbuilds]

The pitting was too bad so I ended up buying new forks to stop the leaking. Even with new seals they leaked too bad. If you watch closely, when I put the spring and boot on, you'll notice they were changed.

[@rhuemulhollen2496]

Mind sharing where you got your new forks? Just pulled mine off of my 73’ and the tubes are shot. Everything else is good.

[@jcowen2670]

Was putting in 4.4 oz & it over filled. I did bounce it empty before adding.So how far from top should oli be? .

[@bottomupbuilds]

Was that after a complete disassembly, or just a fluid change? Honestly, these forks are really basic and I don't know if you'd even notice if you had under filled or over filled the fork just a little.

[@jcowen2670]

@@bottomupbuilds it was a fluid change. I pumped all the fluid out & attempted a 4.4 refill. Got about 3.5 in it when overfilled. Now I need to know where to set the level & then I'll pull so much out to that level. So, what is the high level?

[@bottomupbuilds]

@@jcowen2670 The manual says 4.1-4.4 oz on a fluid change. I don't know what level to set them at from a visual standpoint. if you can 't get 4.1 oz into them it's possible all the fluid isn't draining as it should. Sorry I can't be more help.

[@justinpeters6013]

This is a well done video. I actually did this to my 1969 Ct 90 11 years ago. Seals leaking for the first time since. I looked this up to remind me. You did a great job filming and explaining everything. I hate when everything is paused then comes back to no explanation 👍🏼 thanks!

[@justinpeters6013]

I am curious where you found new fork tubes 11 years ago mine were shot! I remember taking jb weld and filling in all the craters. I then filed and sanded smooth. It’s worked without a drop all these years. Today we were using the bike to place hooks on our flat bed. We bottomed forks out with tie down, and here came the fluid. 🤦🏼‍♂️ Knew better but did it anyway…

[@CH-xu7rl]

im building a 1971 ct90 , i purchased a 1978 transmission, do you know what cylinders i can use for that. any suggestions.

[@bottomupbuilds]

I would recommend anything that is recommended for the year the case was made, just make sure your piston size matches your cylinder bore and it should work.