1981 4,500 mile time capsule project

[scorchnoma]

I stumbled upon this forum while looking for some parts a few days ago, and thank God something like this exists.

I am about to start on a project bike that has been sitting approximately 25 years, maybe more. 100% original, as far as I know, the two previous owners are family friends. The first owner bought it new, realized it had bad rings from the factory (would run but foul up quickly). For some reason, he never took it back in to have the factory defect fixed, just kept cleaning/replacing the plug that would foul every few rides. After a couple years of barely riding it, he sold it to another friend, who managed to lay it down in a slow speed corner (gravel) and decided he didn't want to ride it again, and as such it began its long storage period where it was stored inside a house and later in a garage for a few years.

About 5 years ago it came into my possession and I haven't gotten a chance to work on it until now. Last summer I took stock of what I had. All of the electrical seems to work and the engine freed right up immediately so nothing is seized. There is absolutely no rust/corrosion aside from some surface stuff on the chrome that wipes right off with some elbow grease. The game plan I have so far is to get it running safely, get comfortable and confident riding it (this is my first motorcycle), and then start doing some cafe style modifications once I feel I know it well enough.

What I assume I will have to replace:
-the bad factory rings
-might as well do the bearings while I am in there
-rebuild carbs
-thoroughly clean the inside of the gas tank
-All hoses/tubes, basically anything rubber.
-tires

I do have some questions though:
-Did I miss anything in the list above in the basic barn find style general get it running again checklist?
-Is there any chance of the forks/shocks surviving the extended storage or should I just plan on rebuilding/replacing them no matter what?
-Are there any good places to start for complete rebuild kits (carb, engine, etc)?

Thanks in advance for any help, and thank you to whoever (or the multiple whoevers) that put this forum up.

Some pictures:





My oldest daughter trying to encourage me to get it running a few years ago back when we moved into our new house.

 

[bcware]

Plan on rebuilding or replacing all components that move and many that come in contact with fuel: steering stem bearings, forks, shocks, chain, the cables, wheel bearings, swing-arm, petcock, etc.

First and foremost focus on things that make it stop, start, or steer. I would honestly recommend tearing it down pretty bare. You don't need to pull the motor or anything, but it should get a good once-over just to make sure all of the nuts and bolts are still tightened to spec! It also makes it MUCH easier to clean.

If you've never really taken something like this apart don't fret. Some of the guys on here have pretty much memorized how everything goes back together and we can help out. I think by the third time I tore mine down I had it back together in 2 8-hour days

 

[Scorpio1963]

Congrads hope the prject goes well for you,just as a note you mentioned replacing the bearings.Just to let you know they are impossible to find because they are no longer made or stocked by the dealer.I would suggest if the engine doesn't knock when you get it running just leaving the bottom end alone and only tearing into it if you have to.Also you might get lucky and find a set on ebay.They also come in different colors fo stock crank or oversize.just a heads up.

 

[xschris]

Good find and welcome to the forum. Ebay is a good place to find a lot of the parts you will need. It don't hurt to try a local yamaha dealer some will have stuff on the self new from back in the day. If you go to yamaha.com and look up the part numbers you can then google the number and come up with more sources.

 

[willem]

nice bike! Haven't seen the front fork oil change mentioned yet. But yes basically you'll have to take it all apart quite far to make sure everything is ok. Stuff like greasing the swingarm bearing.

If you want some reference materials, here you go: click

good luck and keep us posted

oh and I think it's smart to go about it the way you are, get this bike functional and stock before doing any mods. This bike would also make a great restoration project, keeping it bone stock (or at least doing no irreversible mods) usually keeps its value up more than going at it with a hacksaw. But in the end, it's your bike and if you want to cut it in half just go for it

 

[scorchnoma]

Thanks for all the help, looks like I'll be adding rebuilding the forks to that list. Good to know that I can (hopefully) not have to do the bearings. I will be posting updates but it's going to be slow going until it warms up significantly here, it's been the winter that never ends in Minnesota.

 

[willem]

wouldn't skip the wheel bearings and swingarm bearing though but yea my guess is that you can leave at least the bottom end of the engine alone for now

 

[Oskar]

Sorry to have to ask, but are you sure the rings are bad? Was this a known problem with these bikes that I am unaware of? Could it be as simple as bad carb mixture?

Not doubting anybodies word, but Yamaha pretty well had thier act together, and rings surprises me.

Thanks, Geoff

 

[willem]

I had the same thought actually, never heard of rings being bad out of the factory.

How did you diagnose the problem?

 

[bcware]

My friend bought a '75 cb360 with a "bad motor." It turned out the previous owner was just clueless. I cleaned/adjusted the carbs and gas tank and it fired right up. There is always hope with Japanese bikes!