2000 yz426 RUNNING PROBLEMS

I Recently Replaced The Gas Tank On My Bike. I Hadn't Started The Bike In At Least 3 Or 4 Months. When I Started The Bike It Would Run Fine With The Choke On, In Other Words Run Like It Normally Would With The Choke On. But, When I Turned The Choke Off The Bike Would Just Die, I Tried To Fix This Problem By Following Turning The Choke Off I Gave It Gas But All That Would Happen Was The Engine Would Pop Several Times And Run Very Rough Then Eventually Die. Is There Any Advice You Might Have As To How I Can Troubleshoot This Problem?

Thanks

You have a plugged pilot jet most likely.

Remove the float bowl nut - 17mm

Then remove the pilot jet. To make it easier you should rotate the carb so you can see what you are doing. Or just take out the carb, it is easy on a 2000.

Clean out the pilot jet with a piece of wire and carb cleaner. Also spray cleaner into the jet cavity.

B-12 Chem Tool is best. Or maxima contact cleaner. They don't leave a residue.

Check your manual if you get really confused. Or post your question and we can help answer it for ya.

you might have loosened up some debris and it went down into the carb before removing the tank - then got sucked up into the pilot

First, let's turn off your Caps Lock.

Then, realize what the symptoms mean: it has enough fuel to run off of the starter circuit while the choke is on, but once you turn it off, it quits. That indicates a blocked pilot circuit. Remove and clean at least the pilot jet, check for water in the fuel, and try again.

Caps Lock......

That was throwing me for a loop too.... :p

You have a plugged pilot jet most likely.

Remove the float bowl nut - 17mm

Then remove the pilot jet. To make it easier you should rotate the carb so you can see what you are doing. Or just take out the carb, it is easy on a 2000.

Clean out the pilot jet with a piece of wire and carb cleaner. Also spray cleaner into the jet cavity.

B-12 Chem Tool is best. Or maxima contact cleaner. They don't leave a residue.

Check your manual if you get really confused. Or post your question and we can help answer it for ya.

Good advice and you hit the nail on the head, but I wouldn't advise anyone to use a piece of wire to clean any jet. If carb cleaner and compressed air don't do the trick, the jet should be replaced. :p

I've cleaned innumerable jets with wire that could not have been cleaned any other way in the absence of a professional grade dip can. The risk of damage to the jet is minimal if any caution at all is used to avoid scuffing it up.

I've cleaned innumerable jets with wire that could not have been cleaned any other way in the absence of a professional grade dip can. The risk of damage to the jet is minimal if any caution at all is used to avoid scuffing it up.

Working in an ATV shop, can you imagine how many I've seen that have been damaged by wire, torch tip cleaners, & drill bits?.... Its not the right way to clean a jet.

That's NOT caps lock, it's an overly strung out ring finger on the shift key!!!

Probably the aftermath of too much Redbull!

You could be right, but the software at this site will occasionally reduce an all caps string to text like that. It's really hard to imagine anyone actually typing like that when few of his other posts are that way.

Look at the title of the thread: All Caps except for where he shifted to type "YZ"

Good advice and you hit the nail on the head, but I wouldn't advise anyone to use a piece of wire to clean any jet. If carb cleaner and compressed air don't do the trick, the jet should be replaced. :p

Probably a good call. I have noticed that when a jet has been totally plugged with gunk it is more prone to growing varnish. Jets are cheap, I would much rather put in new jets than spend my time cleaning one that is really really dirty.

Corrosion is one thing, but varnish doesn't "grow back" once it's been removed, unless you turn around and store the vehicle long term again.

I apologize for dealing you all such grief for typing in all caps lock. I hope I have not adversely affected you life in an unforgiveable way. Thanks to you guys who stayed subjective, I appreciate the help.

I apologize for dealing you all such grief for typing in all caps lock. I hope I have not adversely affected you life in an unforgiveable way. Thanks to you guys who stayed subjective, I appreciate the help.
I was fine up until the sarcasm came out. Note that each of my posts except the one in response to Matt was on topic, and addressed your specific issue.

When you ask for help from a group of relative strangers by using written communication, it is simple courtesy to make your writing as easy to read and understand as possible. No one is picking on you, just trying to steer you in a better direction. You need not apologize, but neither does anyone here, up to this point. (Well, Matt, maybe. :p )

Working in an ATV shop, can you imagine how many I've seen that have been damaged by wire, torch tip cleaners, & drill bits?.... Its not the right way to clean a jet.
Yes, I can imagine it well, after 35+ years as a mechanic of one kind or other. That does not change the fact that a jet can be cleaned by any of those means without being damaged if it's done prudently. As I said, I have done exactly that perhaps hundreds of times with no problem whatever.

The key point that must be remembered is that anything that actually alters the shape of the metering orifice itself can affect the function of the jet in a negative way, and caution must be taken not to do so in any way. Even a small nick in the bore or at the opening of it can show up negatively. Anything inserted into a jet orifice should always be smaller than the orifice itself, and only be used as a pick to dislodge a varnish deposit. Beyond that, the risk you mention is quite real.

You have a plugged pilot jet most likely.

Remove the float bowl nut - 17mm

Then remove the pilot jet. To make it easier you should rotate the carb so you can see what you are doing. Or just take out the carb, it is easy on a 2000.

Clean out the pilot jet with a piece of wire and carb cleaner. Also spray cleaner into the jet cavity.

B-12 Chem Tool is best. Or maxima contact cleaner. They don't leave a residue.

Check your manual if you get really confused. Or post your question and we can help answer it for ya.

As an update: I did exactly what you said, I even removed the whole carb and took a look at the inspection points for it as referenced by my manual. Unfortunately none of this worked. If anything it now runs worse with the choke on than it did in the past. I am starting to get the feeling that the diagnostics and repair are out of my ballpark. But still does anyone have some kind of input as to what else may be wrong? Thanks again for your help.

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