83 XS400 Maxim .... Feels like it's starving for fuel

[G-Gaurd]

Hey hey hey .... XS400 maxim .. feels like it's only running on 1 cylinder and runs rough ... When I accelerate and use the choke I get a big boost in performance ... Like it's been starving for fuel

What's the best way to check if the cylinder are firing ?
Pull the plug wire and start it up?

 

[G-Gaurd]

Pulled plug wires and both cylinders are firing
Starts without choke .... Idles ok
I think I should pull the carbs and have them rebuilt by a professional

 

[spectra]

Have you opened up the carbs yourself? Not that big of a deal to open them up and clean them just clean them really good.

 

[NewHavenMike]

Open the tap on the 2nd fuel bowl and see if fuel runs out freely. Sending those carbs out for cleaning will probably get you ripped off. You need to be mmechanically inclined to own one of these old bikes or you should just get a modern bike...

You can take the carbs off and remove the fuel bowls. Remove the main jets and make sure the passages are clean. Thats probably your issue. You could probably get away with using carb cleaner to blow out the passages. But you will need a thorough cleaning eventually.

 

[Jeff0133]

As always...start by cleaning the carbs.
I've bought a couple of bikes for dirt cheap(200$) from owners that thought their bikes were done for cause they ran on one cylinder.
So i stole the bikes....got home...cleaned the carbs...and guess what...2 cylinders!

 

[not yet known]

yup... bunch of orange goo..

 

[G-Gaurd]

Totally totally totally cleaned out the carbs .... Twice ... Now she flys like a bat out of hell ... I'm amazed at how much power this little 400 has .... Lol

 

[xschris]

Make sure to use an in-line fuel filter to keep them clean.

 

[Jeff0133]