99 XC 500 running waaaaay rich

[xcr440]

Looking for opinions.

99 XC 500 with the rack mount flat sides.

This weekend, unless you pinned it to the bar (Even below zero) it would load up all the way to 80-90% throttle before it would start pulling like it should, and only after a few seconds of wide open, would it clear up.

Choke plungers stuck? (Doesn't feel like it, but I can tell I'm pulling on the springs right away with the choke lever)

Needle and seat? But wouldn't that just let gas run in while sitting? It doesn't do that.

Already dropped the pilot jet one number last summer.

It used 7.1 gallons in the same distance the 700 I was riding used 4.6 gallons. So something is a mess here.

Any other thoughts? Thanks ahead of time.

 

[dofo1]

If you don't think its the needle/seat or enricher's there is still at least one more way for fuel to get into the engine.

A bad diaphragm in the fuel pump. Pull the vacuum pulse line of the fuel pump and see if there is fuel in it.

 

[xcr440]

If you don't think its the needle/seat or enricher's there is still at least one more way for fuel to get into the engine.

A bad diaphragm in the fuel pump. Pull the vacuum pulse line of the fuel pump and see if there is fuel in it.

Sounds like a good suggestion I didn't think of. First thing I will check.

 

[D.B. Cooper]

Sounds like a good suggestion I didn't think of. First thing I will check.

If that's the problem, (leaking fuel into the crank case) remove the drain plugs in the case, pick up the rear of the sled if need be and drain the raw fuel out.

Then mix approx 1 quart of oil into a full tank of fuel to get some oil back into the crank & rod bearings

 

[xcr440]

If that's the problem, (leaking fuel into the crank case) remove the drain plugs in the case, pick up the rear of the sled if need be and drain the raw fuel out.

Then mix approx 1 quart of oil into a full tank of fuel to get some oil back into the crank & rod bearings

Its not leaking into the case while sitting, its loading up while running.

 

[motor_slut]

Were you riding in powder? Is so you might have snow ingestion which plugged the pilot circuit and caused this.

 

[xcr440]

Were you riding in powder? Is so you might have snow ingestion which plugged the pilot circuit and caused this.

Nope, trail riding, maybe a little snow dust from following, but not enough to cause an issue, at least I wouldn't think.

 

[xcr440]

Well, fuel pump baffles look perfect, held them under a light and looked in tact.

On the stand, it will "4-cycle" at idle, loading up, and as you ease into it onto the pilot, it tries to clear but won't, then just a little more and it will open right up.

Thinking drop the needle again, then if that doesn't work, possibly down the idle jet??? Ideas???

 

[xcr440]

Ok, dropped the needle one clip, and seemed to have made a significant difference. I think I'll have the boy ride it this weekend and see how it runs!

 

[dakota]

if it was running good before, dropping the needle is only covering up the root cause. So, when you find the real problem make sure you change the needle back or you will likely melt her down.

I would go back and double check the choke. loosen the cable way up and then back the plunger out of the carb. check the rubber seal on the bottom of the plunger to make sure it is in good shape. when you re-install you should be able to feel it bottom out in the carb and be able to compress the spring as you tighten it back in. now adjust the slack to there is a little play at the choke lever.

 

[xcr440]

Perhaps, but this thing has never quite ran right low rpm. It ran better this weekend with the needle drop, but still wants to load up from 3000-4500/5000 rpm. Above 30mph (5000rpm) and higher the thing ran like a champ, 25-30 degree weather.

Thinking of another needle drop, or idle jet??? I will redo the choke check, thanks for the advice.