Hey guys,

Quick question regarding a 97 Xplorer 500. I picked this unit up just recently and the local outdoor air temperatures are around 23F to 46F (-5 to +8 Celsius).

When starting with full choke and the airbox closed (normal starting) the bike will not fire.

If I either:

A) Use carb cleaner it will fire immediately and so long as i continue to give it little bursts until warm itll then run nicely without any assistance.

OR

B) I found that opening the airbox and taking off the air filter and restricting the airflow with my hand over the snorkel I am also able to have the machine fire up immediately and run nicely so long as I restrict the air with my hand until warm again.

The choke does appear to work once the bike is warm as it will increase the idle when starting as well as stall it out if you leave it on long enough.

Once the bike has warmed up a little i am able to put the airbox back together and it idles and runs fairly well.

I assume by restricting airflow i am richening the carburetor? Choke issue? Dirty Carb? Jet settings?

Any information is greatly appreciated! Thanks [img]i/expressions/face-icon-small-smile.gif[/img]

 

sounds like the fuel enrichment circuit (choke) is partially clogged. i would take the carb off and give it a good bath. also check your cam lobes for the exhaust. that is a known problem with early 500's. make sure they arent rough or just look funky. should be nice and smooth and no/little discoloration

 

So I took the carb off this weekend gave it a bath and a good cleaning, made sure the pilot jet was nice and clean. I think it now has something to do with the choke being properly seated. I'm still having trouble starting it.

Could anyone give me a couple pointers as to how to adjust the choke cable? (its the flip style rather than the pull out style on the sportsman's)

Also, the manual is vague about the difference between the pilot screw and the pilot air screw.

I assume the pilot screw is closest to the intake and the spec shows 1 1/2 turns.

Would the pilot air screw then be on the air box side (air screw according to the diagram) and be set at 2 turns?

 

A little trick is to "double" choke. Just flip lever from straight up ,over to the right which allows more plunger travel. If lever has a LOT of slack when off,there is an adjustment nut that you loosen at carb and take cable slack up,IF this is on your model, some have adjustments on cable leading to carb,does the same thing! 2 to 2 1/2 turns about right. Good luck OPT

 

By "double choke" do you just mean the full position on the choke? (off, straight up, more than straight up...maybe 45 degrees).

If so, the position im using to start is that which would have the plunger the furthest from the seat it sits in with no choke.

The motor idles fine when warm and choke off, which leads me to believe the plunger must be seating properly.

Can anyone confirm?

Thanks

 

You may want to check the fuel passage under the choke plunger. It sounds like it may be plugged and not letting the extra fuel into the engine.

 

Choke lever left (off) straight up (on) fully over to the right (maximum travel) ? Might help on starting? If not then need to check out Good luck OPT

 

Alright so I went and played around again. What I did this time is squirt carb cleaner into what i believe to be the return line back to the fuel pump. I'm not sure if the hoses are correct as I'm not the first guy to screw around with this bike.

Should the outlet/inlet labelled "P" be routed to the carb on the top (engine side) inlet?

If so, should the line from this be dry? It currently was, I've attached pics to better show this.

What exactly does this hose do?

Oh, and just to mention once again, the choke appeared to be responsive at all three positions, and when OFF, the bike idles great. Now if only it would help me when cold! Pilot screw adjustment perhaps?

Thanks

 

Pilot screw should be 2.5 turns, take the top off the carb andlower the e-clip one notcch, this will raise the needle and give it more gas , should help with starting.

 

So I think I've answered my own question, perhaps someone could confirm. The "P" hose coming from the engine side top of the carb to the fuel pump is simply vacuum which powers the diaphragm on the fuel pump. In my case this appears to be in the correct location.

So it seems to me then that if the carb is not rich enough to start even with the choke full open, the pilot air mixture screw is what is need of adjustment (richen mixture).

The pilot air mixture screw is what i believe to be on the engine side past the butterfly with a very sharp point. I have the pilot air mixture set to 1 1/2 turns .

The manual seems to have two values for this one says 1 1/2 the other 2 turns. Would 1/2 turn be enough to make it not want to start in cooler weather?

Also, I am then confused about the other "air screw" on the front (air box) side of the carb. What is this screw used for? Does it impact starting at all? Once started this engine runs great.