XJ900 Choke not working...

Bike runs really great, however choke doesn't seem to work. Linkage slides over as it should, however when I try to warm it up and add the choke it Decreases the idle.
Unlike the other XJ900's I own and have owned this one takes a bit to warm up (including the engine itself).
Thanks!

 

Enrichment circuits need cleaning. They have the smallest jets and seem to plug up first in these carbs

 

With the symptoms he described, chances are they are pretty well clogged.

 

Yep , the high E metal guitar string is the way.

 

Chacal sells the proper size drill bit to clean that jet out. Keep in mind you don't want to ream it out and make it larger. It needs to stay that size. I got a bike from a dude that drilled out those jets. You could hardly use the choke because it would flood the engine out in no time. Careful picking and prodding with wires is the best way to clear the dried gas and goo.

 

Thanks for the replies, although they are probably the worst I could read!

Question is: Will the bike's performance be affected outside of the choke issue, or is this enrichment circuit issue isolated to choking the bike (which is actually a fitting choice of words)?

Believe it or not, I've had really good luck with the Star-Tron fuel additive - especially with the sewage grade, ethanol based gas here in California. Maybe I will add some Star-Tron and put on some aggressive highway miles to see if it breaks up the clog.

 

enrichment circuit is just for the "choke" does nothing else when closed (off). as long as bike is warm enough to start with out it .

 

Living in California should help, and I guess I have the idle screw to turn up if I need a less-convenient surrogate, back-up choke. Thanks for the info, I guess it could be a lot worse, as the bike runs great.

 

Star-Tron maybe good for maintaining a carburetor or fuel system that is working somewhat. If the fuel can't get through the chemicals can't work to open the clog. People buy Draino with the hopes of not calling a plumber, others try carb cleaners with the hopes of not calling a mechanic. "Mechanic in A Can"rarely works for me but you never know when the rarely part happens.

 

how will star tron break up the clog if the circuit is not being used or letting fuel flow through it.
get out your e string and clear that hole.

its 28 degrees here and my 550 is still starting on choke first try , another cup of coffee and i'm off for a ride

 

Thanks. Yup, you are all right - it's logical that I will have to pull the carbs. I was just hoping to celebrate getting the air-box back in a little while longer. Oh well...going to the garage, small E-string in hand (great tip). I hope I won't be playing my 5-string too long.

 

My 750 does the same thing, half choke is the highest idle. Full choke and it sputters and slows down. I don't see it as a problem.

 

For new XJ owners, it's important to remember that it's not a choke, doesn't change the air:fuel ratio by decreasing the amount of air like a traditional choke does. It's a fuel-enrichment circuit, so if those ports in the carbs are made larger by sloppy cleaning (too large a drill bit or using a string from an electric bass, for example) it's going to have excess gas intake all of the time.
I've used the tiny drill bit from XJ4ever to clear out the passageway in master cylinders. Very effective.

I don't think that it would be effective to lean out the pilot screw, if a p.o. had over-enlarged (butchered) the ports, but that's a question for forum members with more experience than me.

 

If the enrichment jets get drilled out the choke system will throw too much fuel in the engine. I have a set of float bowls that are like that hoping there will be an enrichment jet replacement made someday.

 

New plugs gapped and changed, result when warm...
Thoughts are running rich?

 

Or you could adjust your fuel mix to make it run a little rich and not bother with the choke until you feel like pulling the carbs.

Unless it has been reamed and is already rich.

 

Riding with the choke on, shouldn't that give the cleaner access?

 

If completely plugged, probably not. If only partially blocked, perhaps it might work.

Really bad carbs probably always need a teardown. However, I don't think some gas treatments are complete snake oil.

I actually had pretty good success with using Mercury Quikcleen this summer. Local Yamaha dealer said Mercury outboard mechanic said they never tear down carbs if they are at all working, just run this stuff through them.

Using a combination of Quickleen and Sea Foam alternately in each tank this summer, my bike is running better than ever. (Granted there was some other maintenance involved as well in making it run well, but I don't need a carb teardown).

 

I found that a single strand from a bicycle brake cable worked for me. It took a while to find something that had the strength, while being as thin as it needs to be to get into that passage. A stripped twist tie seems like the right gauge, but it is definitely NOT strong enough to do the job... too "bendy!"

 

if that's warmed up fully it either needs synced or the mixture needs adjusted or both.