Enrichment Tube Help!

Okay. Smelled up the house tonight cooking my carbs in a pot of lemon juice and have a question for you guys. Pic below is just an example...



That litle guy I circle -enrichment rube, right? Opens when you choke and sucks up the gas from that extra well in the bowls as far as I know.

Ok - the outside carb (fuel rail inlet side) doesn't have an opening like the one pictured (again, not actually my carbs). The other 3 look just like the pic though. Cleaned, poked and prodded - no hole. Is that supposed to be the case???

I'd take a picture but I don't know the phone camera will do justice.

1981 XJ650 Midnight Maxim. Stock Hitachi Carbs.

 

Re: Starter Jet? Question

No, that is not the starter jet. That is the suction tube for the enrichment circuit that drops down into the passage in the float bowl, and THAT'S where you'll find the starter jet.

And yes, it should have a hole, it's probably plugged shut. The green goo on your main jets is a sure indication that Varnish Reigns Supreme thru-and-thru your carbs!

 

Re: Starter Jet? Question

Lucky me that green goo isn't mine. Picture I grabbed off the net.

So thats the enrichment tube. Gotcha. Still, I have one that does not have a whole - and unless it's plugged with with brass - I would swear it's solid and not grime. None of the others were clogged before the clean, and certainly not after. Is there any why that it's a missed manufacturing error? Anyone else seen this before?

I'll go and hammer a needle on it just to check, but it hasn't broke thru yet...

 

Re: Starter Jet? Question

Has to be clear as Len said - keep working on it - you can try soaking it a bit in lemon juice, pinesol, carb cleaner - your choice....

 

Re: Starter Jet? Question

I'll try and post a pic. I took a steel dental pick to it last night, and all it did was scratch metal... no hole. Any was this isn't supposed to have a hole, but the other 3 are???

 

Had a similar problem - soak in seafoam. I soaked mine overnight in a container filled with seafoam (and covered it) and the next day I was able to 'push through'. At the least, the seafoam will help remove any varnish and/or other gunk in any other passageways.

 

I soaked my bowls in Pine Sol and water mix over night started with hot water and the clogged hole loosened up and I used a piece of small welding rod and stuck it in the holes and now I shot carb cleaner in the hole and there all clear now. Try that.

 

Yes you should have a hole. anyway....

Follow the suggested advice, soak over night in carb cleaner of some sort. While that's going on put your bowls in the dishwasher, cleans 'em right up. (that is if your wife won't kill you) That will soften the crap up in the enrichment circuit so you can clean it out also.

A good over night soak should make it so you can clean the gunk out. You'll need a pretty thin piece of something. I tried using a dental pick and it was too big. Grind your dental pick down some (again only if your wife won't kill you) or get some 28 gauge 'beading wire' from the local craft store that is used to make bead jewelry. It's small enough to fit, and sturdy enough to push through the tube.

 

thanks again for all the advice. sounds like there's no way this is meant to not have a hole (which makes sense to me) the pick i was using fits in the others just fine, but i'll file it down a little. the carbs are actually really clean at this point, i've had them apart a few times just fiddling, and everything was looking pretty good until i noticed that tube. I swear it looks as if it's just soild brass. Will update soon!

 

can you actually remove this tube?

 

You can, but then you'll be buying a new carb body!!! Or doing some fancy machine work to re-install it.....

 

chacal, Have you ever pulled one of those tubes out? Are they just pressed in?

By the way, did you know your pickup tubes are cracked near the tip that goes way down in the bowl? I don't think it affects anything though.

Burnarr

 

Nope, never pulled one out, might be an interesting thing to try while I'm sawing a carb body in half......!

 

That regarding the pic? Wasn't sure - but thats just a generic pic I used.

Regardless... new information has come to light.

After being convinced that this tube should have an opening like the others, I have soaked and soaked and picked and prodded, and then got a little too excited and tapped a punch to it until.... yeah... it bent. And it didn't like being bent back. So it broke off flush at the bowl gasket.

Well, that being said. There IS NO HOLE in the tube. Sure, maybe there is supposed to be, but there ain't. I don't have a single other clog, and what junk i did have was easily clean. But this thing was impenetrable. I hammered a point into the end after the damn thing broke.

So now that it's broke, what can I expect? What exactly did this plugged tube do (or not do). As far as my choke goes - it's always worked just fine for me before (w/ plugged tube) Will it just not enrich that carb/cylinder now? And more important. will it change anything with how the cabrs work WITHOUT the choke on?

 

Haha! I was like THIS close to yanking one of those out of my donor carbs just to see how it was held in there. I had pliers in my hand but kept thinking to myself "You KNOW if you do that, you'll need that donor carb sometime in the future, don't you?" :lol:

The voice of reason was heard and I stepped away from the pliers...

I'd love to see how that bugger is stuck in there. Almost as much as I'd love to see a cross sectioned carb!!

 

So what do you guys think? Will this affect anything besides my choke? And if it was plugged anyhow, should I just expect no difference?

 

Naaa... My comment about the cracked pickup tube was for chacal. Kinda half "challenge" and half curiosity. I've been into eight Mikuni bowls off 550s and 100% of them... All eight of the eight... have tiny hairline cracks in them at the tip where it picks up fuel out of the bowl. I can't tell if it's a fatigue thing or a remnant of the force required to swage the restriction into the tip, or maybe even the force required to get that tube stuck into the underside of the carb body.

Kinda off topic a little and I should probably have started a new thread, but I was hoping to goad him into looking at some of his carbs under magnification to see if his had cracks there as well. I bet they do... :wink:

Anyway, that aside...

Bummer dude... :cry:

That tube supplies fuel to the enrichment circuit. Without that tube, it won't pick up any fuel to enrich that cylinder for a cold start. On the good side... Once the bike is warmed up and running properly and you've got the enrichment lever fully off, I don't think that tube does anything at all.

On the Mikunis the enrichment plunger completely closes off all access to that area when it's fully seated so, at least on the Mikunis, I can guarantee you that it will not change anything in how the carbs work without the choke on. The Hitachis are probably the same, but someone who has been deep into them would need to confirm.

The only other problem is that with that tube snapped off, you'll run extra LEAN on that cylinder when you pull the enrichment lever because you'll be sucking air through the snapped off tube instead of fuel. I guess if you get desperate, you could leave that carb's puller finger linkage off the rod that runs across the rack so you don't ever pull the plunger up on that carb. Just pull up the other three?

Or... You could just pick up a replacement used carb body...

 

Thats what I'm thinking too. I haven't had the bike for long, but it was it a lot worse shape when I first got a hold of it, and it started fine cold. Plus, I'm guessing that thing has never worked, lol - I've been hammering at it even after it broke off - still hasn't show a sign of an opening.

I'm guessing that it'll probably perform just the same when choked as before - and hopefully overall better with all the damn cleaning I've just finished. We'll see. I doubt I'll mess with a new carb body unless I have some unforseen issue, and at that point I'll probably just rebuild them completely (crossing fingers that can wait till the winter)

On the bright side - just heard back from my friend that he was able to extract the broken off exhaust studs WITH the broken off EZ-OUTs!!! And that was without removing the head! I might just have this damn thing back together sooner than I though!

 

Sorry to bump, but I'm really curious what this might/might not affect. Thanks.

 

Sorry guys, just want to see one last time if I can get some opinions on this one.

As mentioned, the enrichment draw tube has broke off, and no longer will drop far enough in the bowl to pull fuel when the 'choke' is on. But at the same time - that thing is plugged solid so it's not like it worked anyhow. Rest of the carbs are clean. Every passage seems to flow freely, no gunk, etc.

My worry is this - what should I expect from them with this tube broken? As I said, it was plugged anyway, so it wasn't drawing fuel or anything. Even when the bike wasn't well tuned, I never had an issue starting it, and the choked seemed to work fine.

Should I expect roughly the same? I'm assuming no enrichment draw/leaner on that cylinder than the other 3 when I've got the choke pulled. But once it's warm and I'm riding with no choke, will it affect anything else?

Thanks for any info. Oh, and I'd read about people using seafoam to clean up the carbs (did mine the manual way) but will it 'clean up' the engine too? Anything you guys recommend running through the fuel to help clean the innards?

 

I don't know Spanky, but,
any way you can drill it out and epoxy in a piece of WD-40 tube ??

I actually have a bristle from a wire brush snapped off in one of my tubes, so I'm curious as to the fix here. I don't recommend using wire brush anymore. . .

 

Seafoam is good stuff it will clean up the fuel system.

I have used it but I prefer the fuel and oil additive from motorkote. It's safe to use with wet clutches. The fuel additive is a good stabilizer for when the bike has to sit for a while, like seafoam it will help stabilize fuel for two years.

www.motorkote.com

Not to sound like an advertisement for them but the stuff works. I use it in my bike, my van, my lawn mower....
I put about 15-20k miles a month (yes a month) on my van. Every third oil change I put in some motorkote, every week I use the fuel additive. My van is a 2001 Chevy Venture with 183,456 miles. I bought it with 70k last September. It runs like a top and gets 26 mpg high way.

As far as your other issue. I can't imagine why that was solid brass tube. It shouldn't have been. As far as running right, it just may with out it, considering the obvious.

I think a chime in from Chacal is needed for this one.

 

The tube wasn't actually solid - it's hollow and the tip looked just like the others, but clogged. But I'll be damned if it just wasn't drilled all the way through. Even after I broke it off, I continued to tried and clear the 'hole' to no avail. Manufacturing error?

The bike ran pretty decent when I got it from the PO, but I've dove a little further into it than I planned, and now just want to get in on the road and wait till winter for the rest. Pulled the engine and cleaned - might touch up some paint... gonna change the oil and filter before I put it back in the frame, should I flush it? Or pull the clutch basket to clean/inspect? Gonna replace the front fork seals too, and some cables... and then hopefully I'll be about good for now.

 

If the stub of a cracked off tube is actually a solid rod (and not a tube at all) and it's completely plugging the hole in the bottom of the carb body, then you'll be exactly where you were when you started. Your enrichment circuit on that carb will be unfunctional due to being plugged (just like it was when you started)

However... If, by virtue of breaking off that tube, opened that hole on the underside of the carb body to the air pocket that exists above the fuel level in the carb bowl, then you will be worse off than before because you'll run extra lean out of that carb when you pull up on the enrichment plunger because you will suck air out of the bowl and into your cylinders.

Does that make sense? :?:

 

Ah, finally. I was wondering if someone would suggest that. Was wondering that myself. Now, this would be an air leak, and a small one at that, in the bowl it self, so it'll be pulling fumes instead of just pure air, no?

Damn thing! Either way... Any suggestions what I might could try and fix it with? Or should I just plug it up to avoid it running leaner than before??

 

Yes, I believe you will pull gas fumes instead of fuel.

Suggestions on how to fix it or how to live with it?

 

Chacal will likely have a used carb body for a fair price. As difficult as it is to get these things right is it worth it to put it back together with a broken enrichment circuit?

 

You could either try to plug what's left of the tube or remove the fork from the rail that opens and closes that plunger.

 

If it seems that the addtion air/fuel fumes from the tube not reaching the gas is problematic enough when using the 'choke', then I think I'll just replug it. I'm already over my budget on this thing and have more pressing things to spend on than a slightly buggered enrichment - I think I'll save that for when I actually need to rebuild the carbs.

Any final objections or ideas?!?!

 

Let us know how what happens.