A month ago i bought my first bike a yamaha Seca xs400. The guy told me when i bought it he had the carbs completely rebuilt, new battery, new spark plugs, and flushed out the gas tank due to it not starting. When i bought it it seemed it ran and started just fine until i got it home it was just really cold blooded i thought(Full choke only) but it always started at least the first couple times. The past two weeks i've been having a hard time getting it started. I charged the battery and tested it to make sure that wasn't it. There is plenty of gas in the tank. I pulled out the spark plugs, and one of them was pretty wet with gas and the other not so much. I cleaned them both anyway and still same results. One strange thing is one day it wouldn't start so i poured .5 gallon of gas in and it started right up, it had 2 gallons in at that time. Also if i leave my petcock in the ON position, a little gas leaks out after a few days. I noticed today that if i push my petcock to any of the three settings that i never see any fuel enter the carb through the clear rubber hose. Is my petcock bad? the bike idles and drives great when i get it started
-
Enjoy XS400.com? Consider making a donation to help support the site.
XS400.com receives a small share of sales from some links on this page, but direct donations have a much greater impact on keeping this site going.
Bike rarely starts :/
- Thread starter Marxworld
- Start date
-
- Tags
- carburetors
XSLeo
XS400 Junkie
You won't always see the fuel flow in a clear fuel line. Unplug it from the carb, put it in a class jar. Now put the petcock in PRI, prime, fuel should flow out.
In ON no fuel should flow, same with RES, reserve.
Now if any fuel flows out in ON or RES your petcock needs a rebuild or replacement.
Fuel should only flow out the ON or RES with the engine running.
A dirty petcock could have plugged passages restricting fuel flow. This could be part of the problem.
Never believe a PO they will tell you anything to sell a bike.
Pull the carbs and do a tear down, cleaning and inspection. www.amckayltd.com/carbguide.pdf is geared more for the XS650 than the XS400, but the XS400 BS34 carbs are very similar to the XS65 BS34 carb. Your specs for jetting needle setting and mix screw settings are different but the rest is pretty much the same. It will help you clean your carbs.
You may find that who ever rebuilt the carbs used parts out of the kit that won't work in your carbs. Often kits come with generic parts that only fit one application and that application is seldom the one you have.
You may need to replace some of these generic parts with stock parts for your year of carbs.
Leo
In ON no fuel should flow, same with RES, reserve.
Now if any fuel flows out in ON or RES your petcock needs a rebuild or replacement.
Fuel should only flow out the ON or RES with the engine running.
A dirty petcock could have plugged passages restricting fuel flow. This could be part of the problem.
Never believe a PO they will tell you anything to sell a bike.
Pull the carbs and do a tear down, cleaning and inspection. www.amckayltd.com/carbguide.pdf is geared more for the XS650 than the XS400, but the XS400 BS34 carbs are very similar to the XS65 BS34 carb. Your specs for jetting needle setting and mix screw settings are different but the rest is pretty much the same. It will help you clean your carbs.
You may find that who ever rebuilt the carbs used parts out of the kit that won't work in your carbs. Often kits come with generic parts that only fit one application and that application is seldom the one you have.
You may need to replace some of these generic parts with stock parts for your year of carbs.
Leo
