What's going on with my bike?

[jaimes-duran]

Hello everyone I have a question. Well my bike is a 1979 xs1100 special. Well I worked on the bike and eventually got it running for a bit at least. It seemed like fuel starvation so I replaced all the fuel lines. I got it started and it ran for about 3 minutes and all of a sudden cut off. I did notice if I tried to twist the throttle the engine would try to cut off. But I looked into the exhaust ports and the left two were leaking unburned fuel. I touched them the right two holes were hot and the left two were like it never ran and cold(the ones leaking fuel). What is the problem and how can I fix it? Thanks for any advice or help.

[bikerphil]

Hate to say it, but it's probably time to go thru the carbs. Do you have good spark at all 4?

[tw1980]

Yep like Bikerphil says go threw the carbs.Look up what to do with a neglected xs11 on this sight.Fallow the instructions and you'll get it going.
Terry

[79XS11F]

If you have raw unburned fuel leaking out the exhaust at the header collars then your flooding those cylinders. So start by checking the oil as it may well be contaminated with fuel now. If so change the oil. If you can, get the front of the bike higher then the back so excess fuel will not flow into the engine. With the bike on main stand, get a board under the front wheel until the back wheel is just touching the floor / ground. This way flooding will be seen out the air box rather then through your engine. Tap on the carb bowls in case a float is fowled in one of the 2 carbs that feed those 2 cylinders. Take the bottom of the air box off so you can see what's going on in there. Also confirm that the air passage ways inside the air box are not plugged. If you have fowled float valves fuel will flow out of the intake stacks inside the air box. If fuel does flow into the air box it's time to pull the carbs and correct the carb problem.
Rob

[jaimes-duran]

well thats a relief. So from what you guys are telling me it is a carb problem and not in the motor. I have went through the carbs 4 times in the last 4 months. I am closely following the steps on this forum. It seems I just haven't mastered it. I will probably get it professionally done. Does anyone know the average price to get a set of carbs done at a shop? Also I noticed the spark plugs are really black and burnt looking. Is this why the bike is so hard to start? Good information thanks fellas

[79XS11F]

well thats a relief. So from what you guys are telling me it is a carb problem and not in the motor. I have went through the carbs 4 times in the last 4 months. I am closely following the steps on this forum. It seems I just haven't mastered it. I will probably get it professionally done. Does anyone know the average price to get a set of carbs done at a shop? Also I noticed the spark plugs are really black and burnt looking. Is this why the bike is so hard to start? Good information thanks fellas

Don't bother taking them to a shop. They likely have not seen carbs like these in years and many shops will charge an arm and a leg and still not solve the problem. I would suggest that you start by checking the long tubes inside the air box that the carb air vent tubes go to. See if you can push a stiff wire through these tubes. If they are blocked the carbs will not vent and they will flood every time. Those tubes in the box are small and bugs love them. also confirm that you have not mixed up the fuel supply and air vet hoses. If you have by mistake reversed them on one side flooding will happen.
Rob

[XSokieSPECIAL]

jaimes

I went through the same thing with mine.

It seems like a carb problem but it's probably ignition.

Check out the pickup coil wires inside the left engine cover. The vacuum advance will cut off the engine when you try to rev it if those wires are bad.

Take the timing cover off and start your bike if it will start. Carefully tug on those wires .....if the engine dies you've found the problem.

Or you can check them with a multi meter. Someone will chime in with the resistance specs.

LUCK!!!

[DGXSER]

MY best guess is that you have a couple things happening here that all go back to the carbs as stated.

Basically, your float needle valves are not sealing, so your flooding the carbs. The flooding is causing your mixture to be Uber-rich and the plugs to foul out which kills the cylinders and you eventually pump raw gas through the cylinders that no longer fire. This is why you get raw fuel running out of your exhaust pipes.

[DiverRay]

With 1 and 2 HOT, and 3 and 4 COLD, IT'S CARBS, NOT IGNITION!!!. I agree with checking the vents for the carbs. The three four pair, on the right side, is probably what you are fighting. As an aside, DO get new spark plugs. Once they foul, the "spark" will flow down the carbon on the insulator, and NOT spark and fire the fuel/air mixture.

[XSokieSPECIAL]

With 1 and 2 HOT, and 3 and 4 COLD, IT'S CARBS, NOT IGNITION!!!. I agree with checking the vents for the carbs. The three four pair, on the right side, is probably what you are fighting. As an aside, DO get new spark plugs. Once they foul, the "spark" will flow down the carbon on the insulator, and NOT spark and fire the fuel/air mixture.

You know Ray..... I could be wrong and it seems that nothing would make you happier.

So I hope I make you really happy.

But you know you can be wrong too and I'm sure you wouldn't appreciate sacastic belittlement for your suggestions any more than I do.

Please just afford me and others the same respect you think you deserve.

HAVE A NICE DAY!!!

[Rasputin]

You know Ray..... I could be wrong and it seems that nothing would make you happier.

So I hope I make you really happy.

But you know you can be wrong too and I'm sure you wouldn't appreciate sacastic belittlement for your suggestions any more than I do.

Please just afford me and others the same respect you think you deserve.

HAVE A NICE DAY!!!

Sorry XSokieSPECIAL, but I can't see anything in Ray's post that is sarcastic or belittleing in any way. He has highlighted and bolded the main point that it has to be carbs in this instance. I happen to agree with him myself. In fact Ray does mention the spark plugs, a part of the ignition sytem, which is in agreement with what you posted. I think maybe you have taken his post a little out of context. My 2 cents

[Montreux_Blue]

As an aside, DO get new spark plugs. Once they foul, the "spark" will flow down the carbon on the insulator, and NOT spark and fire the fuel/air mixture.

Uhhh.... if your cheap you can clean them.... I pull my iridium's out and clean them before every trip with the dremel using a soft brass wire wheel........

Did the in-laws plugs in their truck the same way a couple weeks ago, most fouled up plugs I've ever seen, runs like a top now. The moral of the story is don't buy the cheap grocery store gas.....

[trbig]

So if you find expensive grocery store gas, that'd be OK?


Tod

[Montreux_Blue]

Yes...... yes it would. I'll just say they are cheaper than you think I am ok.

[XSokieSPECIAL]

Sorry XSokieSPECIAL, but I can't see anything in Ray's post that is sarcastic or belittleing in any way. He has highlighted and bolded the main point that it has to be carbs in this instance. I happen to agree with him myself. In fact Ray does mention the spark plugs, a part of the ignition sytem, which is in agreement with what you posted. I think maybe you have taken his post a little out of context. My 2 cents

You might very well be right Rasputin, but if you say THIS IS WHAT I THINK in those bold kiss my tailpipe letters .....that is exactly how it comes across.

To me anyway, maybe it's just me.