hello,

tinkering with a 96 xplorer 400. have compression and spark.

will run with fuel dumped in the carb. took carb apart and cleaned out pretty good.

will sputter once in a while, but will not start. has brand new gas in the tank. bike mixes the fuel and oil on its own.

was wondering the correct settings for mixture screw.

also was curious about the choke. do you leave it out or just pump it a couple times. it is similar to the yamaha fuel enrichment choke they use. a metal rod attached to the cable.

do you adjust the idle screw by sight or by where the bike idles at? since I dont have it idling, was unsure where to start.

thanks for any help.

 

What compression reading do you have?Plus not a good idea to premix and use the injector both. Too much oil could be causing problems. Plus a lot of times just cleaning a carb doesn't work as it may need a carb kit. Around 2 turns out on the air screw on average. It's not as sensitive as a four stroke carb fuel mixture screw. Choke is just a brass plug that opens up the fuel circuit when you pull the choke lever.It's called a plunger,but you just open the choke lever. This is not a push/primer type choke. Item #29.Dirt Cheap Yamaha, Honda, Arctic Cat & Polaris OEM Parts & Accessories – Cycle Parts Warehouse

 

thanks. watched the video a couple days ago before the cleaning.

Ordered a rebuild kit and now we wait. Does the plunger have anything rubber on it or is it just a metal slug?

 

Just a brass plunger. Just flip the choke lever wide open and unscrew the assembly from the carb. Easier this way and the plunger is held tight up against the spring so it won't accidentally come off and you have to get on your hands and knees hunting a spring and plunger.

 

Got my carb kit. installed everything as per the video.

I only got it to sputter twice, didnt fully start. When I let go of the throttle, the sputter stopped. Also, I am guessing I should leave the throttle adjustment all the way out so it is no used and I adjust that when I get it running.

I have tried the air mixture every which way from 1/4 to 3 turns out. Fluttered the throttle with no success, only twice a sputter.

My main needle was a little corroded. There was a set of grooves on the top, I picked the second from the bottom. This is what was original. Should I remove the throttle and see if I have any different results?

I am unsure if I should get a new main also. One was not included in the kit.

Thanks for any help.

 

Again what was the compression reading you show? This is important. Plus if it's still not starting it could be this, crank seals leaking or something else.

 

120 psi.

I am gonna get a new plug. any idea what gap should be?

 

Low end on compression on the 400 engine. Average on a good bore is around 135-145psi. Has to have a good top and bottom end compression(seals) to atomize the fuel/air/oil mixture properly to run. Crank seals are what a lot of people over look on 2 strokes also.Only way to test the seals is by a leak down test,but as cheap as they are I'd replace them. It's a little work,have to pull the drive clutch and flywheel and stator on the other side along with checking out the piston to cylinder clearance and getting the next over size that will clean the cylinder bore up.I know it's not what you want to hear,but it's probably wasting your time until you address this.

 

the test was dry, Ill try a wet compression test. thanks for the help so far.

 

good news, new plug and it fires right up.

bad news, leaking oil from the bottom of the exhaust pipe near pull start. does this mean the exhaust pipe is bad?