Having trouble with 82 XJ650 Carbs, Gas leaking from pipes

Hello Everyone, I wonder if you guys can help me . I just got a 1982 XJ650 from an owner who said it was running a year ago and then had carb problems. It starts but bogs down to stalling the engine off, and then I see Gas dropping from the bottom of the muffler/header connection. I cleaned the tank prior to this and I thought I cleaned the Carbs , new gas lines , tried running with an open gas tank cap, to see if its a clogged air vacuum problem. I understand that the carburetors need some major work but what would create carbs to drown the engine with gas and not run past idling and bog down. I am learning about these bikes as I go , my first XJ650 but pretty mechanically inclined just someones help here to direct me to the correct repairs. Thank you all in advance.

Oh and please if you can respond to my email here L356912@yahoo.com. Thanks.

 

Sounds like you're flooding out. That can be the result of a number of things.........

faulty petcock
clogged carbs
plugged airbox

How many miles on the bike? May need valve shims checked.
What do you call "cleaned the carbs'.

We will probably be posting replies here, rather than sending emails to a new lister who we don't know. So, you're better bet is to watch right here. Also, it allows anyone else who may have the same issues to see the answers.

Welcome aboard! Stick with us and we WILL get you up and running. Sometimes it's quick and painless, other times it takes quite awhile, but we ALWAYS win.

Dave F

 

The BEST advice I can offer you is to acquire a Workshop Manual for your bike.
The Genuine Yamaha Workshop Manual in Soft Cover would be best.
You'll have a combined OWNERS Manual <> WORKSHOP Manual specific to your bike.

There are Aftermarket Books: Haynes and Clymer.

Flooding ... "Generally" occurs because the Vacuum Operated Petcock Valve has aged and is leaking Fuel to the Carbs.
Installing a Shut-Off Valve will bring the Petc0ck flooding under control.
Rebuilding or replacement will address the leaking pet0ck.

Carb Float Valves ~ Float Height Adjustments.
If the Float Valves are worn they'll need to be replaced.

Be sure you know how to set the petcock.
TEST Petcock.
. . . . . . . . . .

Recommendations:
Get Manual
Test Petcock
Replace Petcock
Carb Cleaning ~ Carb Kits ~ Floats Adjusted.
Perform ALL Service and Maintenance Requirements listed in the Owners Manual and Workshop Manual's --> "Periodic Maintenance Requirements"

 

Re: Having trouble with 82 XJ650 Carbs, Gas leaking from pip

Thank you so much fir taking your time and answering my concerns here. Indeed I will try the petcock tests and may have to get into the Carbs a bit more. This is a great site with great people. Thanks so much!

 

oh, yeah...... you WILL have to get into the carbs more. You'll get into a lot more than just carbs, too! But that's all part of the fun. Pay very close attention to what RickCoMatic, myself, BigFitz, as well as others tell you. We collectively know these bikes pretty much inside out. What one doesn't know, someone else does.

Dave Fox

 

Hey Jim, before you even think of running the bike again sniff your oil, sounds like you could have gas in there!
Running an engine like that for even a short time could cause major engine damage.

 

Re: Having trouble with 82 XJ650 Carbs, Gas leaking from pip

Thank you guys, when I brought the bike home I did drain the old oil and found a Lot of gas in it. At first I was wondering why there was over five quarts of oil in the engine but the smell if gas confirmed the tanks contents ended up in the engine. I will closely watch, listen and learn here from you guys and I greatly appreciate it. I used to build VW and Porsche motors but bikes are new to me. I love the challenge. Looking forward to more of your advice and teaching. Thank you.

 

Re: Having trouble with 82 XJ650 Carbs, Gas leaking from pip

Hello, I have a 1982 xj650 with one carburetor leaking, which I think that the float or needle is stuck, does anyone know a way to fix this problem without removing the carburetor? I am new to this bike.

Thanks

 

No; not to "fix" it properly.

STOP running the motor. There is a very good chance that the carb is also dumping gas into the crankcase and polluting your oil.

You're going to need to pull the carbs and properly service them and verify the float level adjustments.

There is also a whole lot of other work you'll find you're going to need to do. Your first step should be to get a service manual, you're going to need it.

 

Thank you for help, I should have mentioned that the bike had no problems until it set around for a month while I was out of town.

 

Everything I said above still applies.

You are going to discover there is more going on than you realize, trust me. Get a service manual.

 

My experience with the carburetors on the Maxim I have is that you do not want to to a quick or partial cleaning and tuning if you have no personal history of the bike. You will save time and effort in getting the bike to run correctly by replacing the pilot o-ring,washer and springs, needle valve assembly and washers, throttle shaft seals, fuel rail seals, and insure that the all the jets are the correct ones for your bike. Then spend time on cleaning the carbs thoroughly, the church of clean post is a great guide. Don't take any shortcuts and make sure that you verify the clunk test on 4 carbs, wet set the floats accurately and a great bench sync. By doing this it may save you from having to repeatedly remove the carbs to fix or check something else to get your bike running. Before you can dial in the tuning, you have to have the valve clearances in spec. This is a great time to to that. Once you have it all back together and running, then you can vacuum sync and then tune the a/f mixture. You know you have done right when your cold bike starts at a touch of the starter button with 3/4 to full "choke." I learned my lesson the hard way... hope this helps

 

I'll second this--from experience.

 

Thanks to all of you for your excellent knowledge on the xJ650, I have two from 1982, it's time I learn how to repair them properly. Maybe I will just overhaul them both at the same time.

 

Overhauling probably not needed. Just catching up on neglected maintenance and bringing them up to spec. The antique bike guys refer to it as "recommissioning" and I think the term fits us as well.

Nothing anyone has suggested is "major." It's all just part of proper routine maintenance that has likely been largely ignored.

Get a service manual and study up.