bad fuel mileage no power

here we go my 85 maxim xj700 im getting about 50 miles on a tank of gas and im losing power i know that im only running on 1&4 just dont know why im getting spark to all four

 

Are you sure your carbs are clean? Has it been like this since you got it?

 

Old chineese saying, "Sum ting wong" comes to mind. There must be a carb issue going on in there. 50 miles to a tank full? Ya, and no power? I can't think of where to start with that one. Maybe a brake is draging? Something must be holding it back or the engine is just plain running way rich.

 

Hopefully its nothing obvious like a bad fuel leak. I bet there is black smoke comming from your exhaust, way too moch fuel burning. Pull the carbs and clean them. Pay special attention to the fuel enrichment (choke) and float height.

 

Strangely enough, you answered your own question. You are getting bad mileage and poor power because you are only running on 1 & 4. Next step, figure out why you are running on 1 & 4 only. Probably not solely due to the carbs, as it would be unlikely that 2 & 3 are completely gummed up but 1 & 4 are fine. My first guess would be weak spark on 2,3.

It's possible to be getting spark but not have the cylinder fire. Before you pull your carbs, check the compression, spark plugs, coil resistance, maybe even run some seafoam through it to see if it helps. Pulling and cleaning the carbs is a big deal, and likely needs to be done, but doing it first when it could be the spark is simply bad troubleshooting.

Sorry everyone, but it seems that carb cleaning is everyone's first thought here, but how would you feel (I would feel dumb as a rock, personally) if you pulled the carbs to clean them, only to discover your bike wouldn't run because you were out of gas. There's a reason we start with the simple things first!

 

could also be a plugged up air filter...........

 

could also be a plugged up air filter...........

 

A plugged air filter would fowl all 4

You could double-check the coil by switching the little 2 wire connectors, and all 4 plug wires so that the 1/4 coil fires the 2/3 plugs.
This double-checks the 2/3 coil.

Then after switching the above back to normal,
try squirting just a little starting fluid into 2 and 3 while running.
Spray into the air box.
This confirms that you need to "do" the carbs.

 

How does one spray fluid into just one cylinder? I asked how to use starter fluid a few days ago and was told to spray it into the air intake duct.

What is the air box? The housing for the air filter and intake duct?

 

With the air filter out, try to spray into the center 2.
Sometimes you can put a carb cleaner straw into a starting fluid spray nozzle. You can also staple a small rag to a paint stir stick, soak it in gas, and wave it in front of your suspect carb inlets.

 

found the problem lil more drastic than i hoped but not life ending lol intake valves were not adjusted properly up and running again thanks for the help everyone yall ride safe