Project 1976 Yamaha YZ400

[craydds]

Originally Posted by Scootern29

Hey Ray, for cleaning up gunky, icky stuff, go to a dollar store and get some LA's Awesome cleaner it works great. I actually said icky.

Thanks for the tip. I am always looking for some magic formula. A HUGE amount of time is spent on cleaning up icky - there, I said it, too - parts. I will try that LA's Awesome stuff. So timely, I have been cleaning dirty parts all evening. The good thang is that all is in fairly good condition - just dirty!
p.s. I like my KLX, it is a really good all-around bike. I could use a bit more power sometimes. Maybe that's why I've been wanting for a monster 2-stroke. I was looking at CR500's - they are asking high $$$ for those bikes. Found this OLD YZ400 on CL and bought it. I knew it was going to be some work. Turns out, it's going to be a big chore, but that's the way I roll:

Occasionally I will see an old monster 2-stroke on CL - KTM, Suzook, Yamaha, CR500, etc., - makes me drool. I think Supershaft has a thread in 2-smokers about old Maico's; those bikes had SCARY power. Too much fun...

[Scootern29]

Jack!

[craydds]

Years (decades) of dirt:


Hours and hours of hard labor:


Shock shipped off to Race Tech:


Parts all over the house:

[craydds]

Piece by piece, clean and paint:


I make lots of photos, mostly so I know what parts are what and how to put it all back together:


Need that shop manual. Found some parts diagrams online that help:


Baked on grease is the hardest to remove:


Several hours later and a few coats of paint:

[craydds]

Silencer:


Expansion chamber:


Frame:


and:

[craydds]

When I first brought the bike home I found the clutch very stiff. After a few can of Berryman's and penetrating oil I cleaned out years of rust and dirt inside the clutch cable. Seems to slide smoothly now::


Front brake. Oh, joy:


More work to be done:


In a few more months I might get it all put back together. Stay tuned.

[craydds]

Any tips on how to polish up the old plastic?

[Scootern29]

Use some fine steel wool to take of the oxidation. Then use a heat gun to melt the plastic. You have to be real careful as you do this. You will see the color come back out of the plastic. The downside is I did a Yamaha tank and I think with the new fuels and the heat gun it made it brittle and it cracked big time.

[craydds]

Originally Posted by Scootern29

Use some fine steel wool to take of the oxidation. Then use a heat gun to melt the plastic. You have to be real careful as you do this. You will see the color come back out of the plastic.

I will work on it... tomorrow. Thanks!

[craydds]

Just messin' around cleaning stuff:


Brand new old parts:


Seems like the old YZ is complete, not missing any original parts, just encrusted with decades of grease, dirt, and corrosion. Broken throttle:


If you can't fix it with JB Weld:


it can't be fixed:

[craydds]

JB Weld sanded smooth:


Coat of paint:

[D.T.]

Looks like fun! Glad it's all there.

Pics when done!

[Scootern29]

I just noticed something. The head on your bike is not stock. Is it a Webco or?

[craydds]

Originally Posted by Scootern29

I just noticed something. The head on your bike is not stock. Is it a Webco or?

You must know more about that than me, I did not even notice. Guess I'll have to do some research.

[craydds]

Theses are AIR forks! Actually held air pressure:


Time for fresh fork oil and seals, too:




These are the upper, high pressure air chambers: