I own a clean low mileage xj-550 maxim. I have heard it run, problem is I can't get it started. Petcock is bad only flows in prime position, and it is missing the vacuum line. Where do I look first?

I own a clean low mileage xj-550 maxim. I have heard it run, problem is I can't get it started. Petcock is bad only flows in prime position, and it is missing the vacuum line. Where do I look first?

Get a petcock rebuild kit and replace the vaccum line....if it has been sitting for a year or more it might be gummed up.....starting fluid will tell you if its a fuel delivery problem....goooood luck.

Are you saying that the fuel doesn't flow from the tap in the ON position with the engine stopped ? If so this is correct as the tap is vacumm operated and should only flow in the On/Reserve position with the engine running.If the vacumm line is missing from the fuel tap to the stub on the inlet manifold then this is your problem and you won't get fuel flow from the tap in the ON or Reserve position with the engine running .Tony.

Are you saying that the fuel doesn't flow from the tap in the ON position with the engine stopped ? If so this is correct as the tap is vacumm operated and should only flow in the On/Reserve position with the engine running.If the vacumm line is missing from the fuel tap to the stub on the inlet manifold then this is your problem and you won't get fuel flow from the tap in the ON or Reserve position with the engine running .Tony.

Thanks Tony, that is exactly what I am saying. The vacuum line simply runs from the petcock to the #2 intake? Is this correct, and if so I should just replace the line and then place petcock in prime to start and then switch to on after it starts. Would sea-foam be safe to run through the carb to help clean them out a little? Bike has not run on a regular basis for at least 4 years. Again,Thanks for the help

The vacuum type tap you have operates from a vacuum from the engine inlet manifold that is why you should have the pipe running from one of the inlet stubs to the tap. So when the engine is running fuel flows from the tap in the ON or Reserve position. When you stop the engine the tap shuts the flow off. In normal use you leave the tap in the On or Reserve position. The Prime position is for when you have drained the carbs or run out of fuel and is used for initially filling the carbs then should be put back to On or Reserve.You can check the tap by taking the fuel pipe off the tap and connecting a pipe onto the vacuum stub on the tap and sucking on it with the tap in the On position you should have a flow and should stop when you stop sucking. Not sure what sea foam is but I would try draining the carb floatbowls first .Tony.

The vacuum type tap you have operates from a vacuum from the engine inlet manifold that is why you should have the pipe running from one of the inlet stubs to the tap. So when the engine is running fuel flows from the tap in the ON or Reserve position. When you stop the engine the tap shuts the flow off. In normal use you leave the tap in the On or Reserve position. The Prime position is for when you have drained the carbs or run out of fuel and is used for initially filling the carbs then should be put back to On or Reserve.You can check the tap by taking the fuel pipe off the tap and connecting a pipe onto the vacuum stub on the tap and sucking on it with the tap in the On position you should have a flow and should stop when you stop sucking. Not sure what sea foam is but I would try draining the carb floatbowls first .Tony.

Thanks again, checked the petcock. It is definitely not working. Fuel does flow on prime. Drained float bowls, now they don't fill. Stuck floats? Or should I rebuild petcocks first and then check flow before removing carbs? Sorry to be a pest but do appreciate the help