What to expect...

I just pulled out my fathers old 81 yamaha maxim xj550 and it sat in the garage for 12 years with a 1/2 cup of gas in it and it ceased the carbs up. Other than the obvious carb rebuild, what else would you guys suggest could possibly be wrong with the bike after sitting so long? i did check the compression on the engine and it was pushing what it needed to start, speaking of when i first tried to start it for the test it started for a split second and died because of the left over fuel in the line. Any ideas on things that i should expect when rebuilding it? thanks

 

Change brake fluid and refurbish calipers...replace old rubber brake lines with braided lines.

 

Rebuild the master cylinder too, and change pads and shoes. Old brake shoes are known to delaminate. Even if there's plenty of thickness on the pad, it can still crumble due to age.

Tires will need to be replaced. New Battery. Consider pulling and cleaning every connector in the harness (I got all the tools from chacal to actually depin and repin connectors, and I actually scrub all of the corrosion off the male ends before greasing and reconnecting).

Change all fluids, engine oil, brake fluid, fork oil. Also, maintain your chain. I don't have experience with this, but I've read that if you oil your chain and it weeps orange fluid, it's rusted internally and needs to be replaced along with your sprockets.

Valve clearances are a must. Although you know the PO, realize that unless he meticulously maintained the bike from 1981->2000 (18 years), you will be making up for 18 years of neglected maintenance + 12 years of sitting.

 

I am going thru this right now with an 82 XJ750RJ that had sat in a barn for ~20 years. To get it running (not ridable, just started), I did the following:
- refurbed gas tank with a POR-15 kit ($45)
- rebuilt fuel petcock ($30)
- rebuilt carbs ($70)
- new battery ($50)
- fresh oil
- new plugs
- valve check
- disassembled, cleaned, and greased starter
Now that I know it runs (it runs well...), I am attempting to go thru it and replace all wear items. FWIW, spreadsheet attached with parts, sources, and prices.

 

in addition - plan on the forks and shocks to fail on you some time after getting the bike tagged. The fork oil will foul your brake pads.

 

Before you start tearing the carbs apart (and possibly breaking a float post if they are severely varnished), try soaking the whole carb rack in a carb cleaning solution, like one of those gallon 'carb cleaner' pails. You'll only get two carbs in at a time, but this may help break down some gunk and make disassembly the rest of the way a bit easier.

You'll want to replace all the rubber gaskets, o-rings, and other various bits doing this, of course.

If the bike has sat 12 years, you will definitely want to replace the rear brake (as previously mentioned) AND put new tires on that bike. Tire rubber isn't eternal, it does dry out and go bad, especially after a decade or more.

 

You would want to at least remove the diaphragm pistons, as they are pricey, if you were to dunk the carbs.

+1 on not breaking the float towers. Buy some Kroil !

 

DO NOT SUBMERGE the carbs unless you plan to break the rack!

The throttle shaft seals are trapped in there, as are the fuel distribution pipe o-rings.