Stuck Bowl needle right after rebuild

So, I got a 2nd set of carbs for the bike that is already running.
I rebuilt them about 6 months ago and set the floats. Never we set it till this morning.
I hooked it all up and Carb #3 overflowed out the top of the emulsion tube.

I shut the IV bottle off, tapped on the bowl, drained half of it out. Turned on the IV bottle and it came up and stopped.

SOOOO. i'm going to pull this apart and what should I look for.
These carbs went though church of clean, all the parts came out including screens under the needle housing. I cleaned out the fuel tube channels and checked every little passage w/ carb cleaner.
What should I specifically look for/double check when I pull it back apart?

 

have you got the carbs remounted on the bike? if so is the bike on the side stand , or centre stand, if the bike is leaning over, the floats can foul on the posts.
if you have the carbs on the bench , check the "o" rings on the outside of the float needle housing, fuel can find a way around the float valve, and flood through bad o-rings

 

I'm doing the wet set so carbs are straight and level on a portable work bench.
There are no "O" rings on the float needle housing for a Hitachi HSC32 carb , just a copper crush washer.
As mentioned, I tapped on the carb and it stopped over flowing then I drained them.
Just moments ago, I double checked the carbs were level and then turned on the IV bottle. Carb #3 overfilled (came out the top two holes on the back)
I drained the bowls and will pull it apart next to look what is going on.
I'm going to pull that float and another float to see if if that float is leaking. I don't now recall if I did a float test or not. I know I did on my other set of carbs.

David

 

So, Pulled the bowls for #3 and #4 and swapped Needle/Floats between the two.
Filled and drained 4 times. #3 overflowed the 2 rear holes on the 2nd but not the first, third and fourth attempts.
When it overflowed, I stopped the flow, tapped on the bowl with back of screw driver, turned it back on and it stopped.

I'll pull the #3 bowl and inspect again. Maybe swap the needle housings.
I"ll also take a better look at the needle housing, maybe a burr or hole is not centered or something. I"m pretty sure they are the originals I cleaned and not from rebuild kits. I"ll check that.

 

I'm not familiar with THAT particular carb although sometimes float bowl gaskets are cut pretty wide and will come into contact with the float causing it to hang up. That wouldn't be readily apparent with the gasket sitting on the bowl so you might want to put the gasket on the carb body to rule that out.

 

-Make sure the float pivot is clean
-Make sure the float pivot pin has no burrs
-Make sure the “stop tab” isn’t bent too much and is allowing the float to drop too far

 

I swapped the Float pin housing and the problem followed the housing. I got this carb set on ebay so I don't know if the housing brass was aftermarket or OEM.
I'm going to look at it some more.
I have a number of ebay/amazon carb kits and they have various housings. One has a sharp edge at the top and others are chamfered
Some of the kits, the pins don't even fit in all of the housings!

I emptied and filled the bowls 6 times but I'm not entirely convinced the other housings are good.

 

Not sure what you mean by “housing”

 

The brass threaded cylinder that the float needle slips into. (Float Seat?)

Stop tab is the little wire on top of the float needle? Those are all fine.

 

Ok, that is the fuel valve body.

so fwiw, I ONLY buy my rebuild kits from Len Chacal at xj4ever.

reach him at info@xj4ever.com

 

I used xj4ever parts to rebuild the first and 2nd carbs I rebuilt.
I had to purchase needles, jets, vac seals, bowl gasket, sealing washers and although not needed, purchased a valve body.
I did not like the valve body, nor needles.
Valve body came with a flat very fine (more fine than OEM) filter screen on the bottom (which actually is on the top when you have it on the bike).
The flat screen has much less surface area on it than the OEM screen and can divot to collect gunk and then clog. I experienced this on my first carb rebuild.
I actually noticed it was very slow to fill the first time using those screens on a clean filtered fuel from an IV bottle.
Later when using OEM screens, no issues.
The wire on the top of the needle also is much higher and tends to not pull when the floats drop.
I put some other needles and cleaned the original OEM screens (which are bowl shaped) and my problems went away.

I spent a little time w/ the fuel valve body last night and it got some friction to it. I also pulled the various ones from other kits. I'll look at any sharp edges and maybe polish the insides.
I want to use the OEM screens and some of the rebuild kits don't have the little part at the end to fit the screen or comes with screens that are less fine than the OEM.

 

I have never had any problem with any part from Len…

As far as the beanie screens… Whether someone uses them or not, I recommend an in-line filter to begin with. A clean tank is a must, to begin with.

Did you have any conversation with Len concerning your findings?

 

I did not talk to him about it.
I think there was fine resedue in my tank after the de rusting happened.
I tried a rock filter but had issues with it. Pulled it off.
I feel I can't seem to get a paper filter to fit the way I want as tight of a space as it is. I don't like filters running horizontally as they trap air and then don't run the fuel through all the paper like it should.
I ended up filling tanks, swashing around and draining through a paper filter back into gas cans several times after pulling rock filter.

This carb set is going onto a 2nd XJ650 I'm acquiring on the cheap this week. I may play around with a paper filter again, I hat to run it along the outside of the carb though that may be the only way.

 

Melnic is correct, the aftermarket float valve units that have the rubber-tipped needles (HCP18795) use a flat screen that has less mesh-screen surface area than original OEM units --- which used a domed screen --- have (although, that flat screen is an OEM design for some models, including the last-available OEM Hitachi float valves).

The aftermarket units that use the metal-tipped needles (HCP17176) use a domed screen just like the originals.....and these units don't use a needle hanger clip since it's not needed --- the purpose of this clip is to prevent the rubber tip of the needle from "seizing" within the float valve seat (due to the rubber swelling), or fuel varnish forming around it (and "gluing" it to the brass seat). Since the clip is attached to the float, as the fuel bowl empties the weight of the float pulling down on the needle will tend to overcome any needle tip seizure and prevent that float valve from remaining closed, even as the float bowl empties of fuel. Metal-tipped needles, although not original on Hitachi carbs, were used on many original Mikuni carbs. The metal needle tips are much less prone to tip seizure and thus metal-tipped needles do not need, nor use (or even accept) a needle hanger clip.

Also, if the rubber-tipped needles are used, note that the hanger clip can be installed in two different ways (orientations). User experience indicates that the clip should be positioned so that the "open" area of the clip (that part of the clip that snaps over the ridge on the top of the needle) should be oriented towards the "back" of the carbs; in other words, the open area of the clip should be towards the airbox.

Since almost all areas of the country now use fuel that has a significant amount of ethanol as part of the mixture, we always recommend (and sell about 10x as many) the metal-tipped needles (either individually or as part of a kit), as they almost never seize within their brass seat.

As is well-known, SIZE MATTERS, and certainly having a small area of filtration is not as beneficial as a larger area (with the domed screen). However, the screens are basically intended for use with a "clean" fuel system (as in, when the bikes were new) and are not intended to remedy a situation where there are many fine particulates in the fuel flow (such a condition will also shorten the life of the fuel valve considerably). The only solution is a thorough cleaning of the tank, and it is always advised to use an in-line sintered metal or pleated paper filter in addition to the in-tank filter.....besides the much-finer filtration that such a filter provides, these filters are MUCH larger in size (size matters.......) than the float valve filters could ever be, and of course, are easily clean-able and/or replaceable (as opposed to digging into the carbs to clean those small brass seat filter screen).

 

Len,
Thx for the feedback.
I am using rubber tip needles in my original carb and this one.
2nd carb I did set for a friend, I also ran rubber tips. He purchased the new seals, bowl gasket/needle and i reused/cleaned all the existing brass parts.
For this one I'm also using rubber tip needles.
He and I have local access to ethanol free fuel which we are both using in these bikes.

 

Just be aware that with the rather multitude of float valve unit manufacturers out there, that mixing needles from one supplier with the brass seats (whether original or aftermarket) from another supplier may not work well, as we've found somewhat significant differences in needle dimensions (length, cross section, etc.) as well as with the brass seats (internal ID, depth, and most importantly, the inside angle of the closure point...which must match the angle of the needle tip) that can lead to "issues"..........

This is the reason why we don't offer the needles as a separate unit (which we know that other places do).........using a needle designed to fit one type (manufacturer) of seat with some other manufacturer's seat may not work properly.

 

Yes, I have noticed that. In the case above, I had to move the float tab to change the float hieght almost 1mm from before.
One of the cheap Chinese kits a friend gave me, the needles did not even fit in the valve housings that it came with on 2 of the 4.

I REALLY wish there was a good How to thread on filters on what to buy and where to put it. If there is one with pics, I did not find it.
thx

 

OK, I think I made a mistake when doing my troubleshooting. I may NOT have switched floats from 1 to 2 initially, and thus when moving the fuel valve housing from 3 to 4, I moved the float too.
I say this cause when I replaced the fuel valve housing, I also marked the float from 4 and then moved it to 1.
Well, I found that if I dumped the fuel, then picked up the carb to move it, that I sometimes had an overfill now on 1.
SOOOO, I had ONE spare float. It was not in the best shape as far as pitting but I cleaned it up more and put it in 1 and now the problem went away.
This time I did not just drain, but I drained, picked up carb, moved around then sat back down. Did this no less than 10 times.
I still don't have a definitive answer on what was wrong and I did look at the float to see if I could angle it to rub on the side of the bowl or gasket and I could not see it happening.
Well, this carb is going into a bike this weekend so time will tell.

BTW, I 3D printed this and it helped #1 setting the dry float level, but also, when I was checking the wet level, It gave me an easy and quick indication of where I was and how much I moved the floats. Much easier than calipers. Plus I was able to check that both floats where even or not

 

Nice little gauge you made there.....
what height do you have the float cut-outs at?
did you account for the the gasket sealing ridge?

I just use a slide rule, as I have a bunch of different heights I work with, but that’s a handy idea

 

I set the gauge to 17.6mm thinking I'd file it down but it came out right at 17.6 and I just left it there. Since having to wet set, its just a starting point. It rides on the sealing ridge.
for the most part, the carbs wet set started out a tad low, so I measured how much I wanted to go up, then set a visual gap to the gauge.
I guess if the 17.5 should be to the surface below the sealing ridge, I could have just made it 17.2 or something?