Topic: Source for new Jet Needle Sets

[Kenzo1979]

So, JetsRus is a great source for main and slow jets, but...

...Is there a good source for Needle/Emulsifier tube sets that are as good of quality/reliable as stock?

I know there are whole carb kits out there that come with these sets, but most of those maker's kits' jets are not relied on so much across the forum.

Specifically looking for 022A carb sets.  But all around curious in general.

[PeWe]

I do not know details about carb numbers.
Yamiya has for CB750 71-76
https://www.yamiya750.com/index.php?main_page=product_info&cPath=246_21_181_141&products_id=659

Maybe used in other carbs too.

[Deltarider]

[...] ...Is there a good source for Needle/Emulsifier tube sets that are as good of quality/reliable as stock?
[...]
Specifically looking for 022A carb sets.

What's wrong with yours?

[Kenzo1979]

What's wrong with yours?
[/quote]

Well, My 550 plugs are always a tad black, sooty, not oily.  And I've addressed everything I can think of except possible worn needles.  It's not to the point where they foul out, so I just ride on.  But my OCD is nagging me to fix it.  Also, I would love to get my hands on some quality spares that I can use as "known goods" to rule out problems in the future.  I have my hands in a few 500/550's and I like to have sets of good parts to use for referencing and troubleshooting.

[Stev-o]

I do not know details about carb numbers.

FYI - 022 carbs are for a CB550K.  Some guys have used them on a 500 too.

[Deltarider]

Kenzo, are you certain air intake is not impeded? Could be something left under the seat. Airfilterelement wettened/contaminated by that blowby-gas thingy maybe, which would impede a proper airflow. Are the small O-rings around the main jets OK and do they seal well? Are needles in the right position? You may want to consult the scheme below.

[Kenzo1979]

Tried to get away with not listing all the been dones, but here it goes:

Since most issues point to carb cleanliness, the carbs were chem dipped with berryman and sprayed with carb cleaner, squeaky clean, and cleaned again several times. Brand new jet o-rings of correct sizes (viton).  Also, later, brand new correctly sized jets from jetsrus installed.  Original needle, 4th from top position - US.  Also tried to raise the needle one notch (3rd from top).  New Carb to airbox boots.  New manifold gaskets.  Brand New stock air filter, was using a lightly oiled UNI filter, also tried no oil uni.  Also ran without tooltray/air screen.  Correct float heights, measured with float gauge, but also checked with clear tube.  Air screws set about 1.5 turns out, but also backed out to 2, 2.5 and even 3 turns out.  All of this back and forth with different possible causes yet no difference in the way the plugs look.   Bike runs great, idles great, carbs are synched.  Great compression, valves are adjusted properly, exhaust is a 4 into 2, stock headers with 2 slip ons.  Again, runs great, but plugs all have an even amount of black to them, never tan or brown.  I have a 500 with the identical setup, plugs are tan.

I’ll still take recommendations on checking anything else, but also…All that aside, Let’s say I was not trying to fix an issue at all. Is there a place to buy good quality jet needle sets?

[HondaMan]

This sounds like 1 of 2 things that I fix often on the 500/550:

1. Leaking intake manifold O-rings at the head. They are the same size as the ones in the valve caps. The lowered vacuum at low engine speeds causes the engine to load up with fuel. The plugs in this situation will usually stay cleaner longer if the bike is mostly hiway-ridden (as a clue).

2. Spark advancer springs are heat-softened now, letting it advance too soon. This makes the engine 'spit back' at the carbs between about 1800 RPM (when the weights are already advanced, too soon) and 2800 RPM, causing the carbs to mix as if the engine were running at lower RPM, which is a richer mixture. A 'quick test' for this is to retard the whole points plate to the "T" mark(s) for the points and install new plugs, then ride it a bit (10 miles or so). If the plugs stay cleaner, it is definitely the springs. I removed no less than either: 1 full turn from one coil or: 1/2 turn from both coils, plus I re-shape the ends of the springs so they are not slack at the no-advance position.

With modern, slow-burning fuels, this problem is becoming much more frequent in the 500/550. Today's Midgrade burns slower than 1970s premium (in some areas, like here in CO, the Regular burns that slow) which makes it act even richer. Modern fuels burn very slowly so as to help light off catalytic convertors in cars and trucks.

[grcamna2]

I like to have an NOS needle & needle jet to use with an accurate,incremental set of wire gauges to fit into the NOS needle jet to compare with my used needle jet/emulsifier tube to see how much wear has occurred where the needle scrapes the top/inside of the needle jet nozzles,which is where the fuel flows upward past the taper of the needles and spills out to atomize before it enters the intake tracts.
I do the similar type measurement to the O.D. of the needle/taper to compare.
These items are very difficult to find in the OEM stock configuration,but well worth the search. 

[Erny]

If I may add my experience with 022A carb set long time troubleshooting  : CB550K K1, stock, 15k miles, engine never opened. Carb set was rebuilt by proffesional, all brass parts original Keihin (jets 38/100)

Advacer springs : at the beginning, I had general issue with all cyl (all black, bike felt as running rich on low-mid RPMs, while running well on mid-high). Hondaman adviced me to check advancer springs - I fixed that with replacement of stock advancer and points with electronic ingition from Boyer Bransden (has embedded advance curve inside ECU - mechanical advancer is removed). Since then, bike was running far better on low-mid, except cyl#2 - that was always black

To fix issue on cyl#2, (I ONLY had issue with #2), I tried all this w/o success : carbs re-cleaning (it was already very clean), float height check, valves adjustment, swap of coils from another bike, new plugs, leak test OK, compression test OK, new O-rings on manifold, 1-2 manifold replacement..
Then I gave up and bought another set (069) - surprise, issue gone from #2! But drawback was worse behaviour on slow-mid RPMs compare to 022A and impossible to sync for unknown reason. So I put 022A back and issue was back again on #2 cyl 

Start inspecting all every small detail on that #2 carb, I check also emulsification tube from inside and found it was quite corroded inside hole where needle goes, with missing "material", making hole rough and obviously bigger than other 3! (have a look on attached photo).

I only had available set of Keyster tubes at hand, replaced all 4 (needled kept original), did sync again and bingo! Issue was gone, no more black plug #2, engine silky smooth on low-mid RPMs! So combination of genuine Keihin needles and Keyster tubes works well. Later on bought genuine Needle/Emulsifier tube sets, replaced all of them and there was no difference, even no sync needed.

This took me 2 seasons to find root cause, now very happy with it

Note: Hondaman's advices are definitely to be considered as general to do/check first (Hondaman knows, we discussed that by email  ) => MANY THANKS Mark for all your advices!

[Kenzo1979]

This sounds like 1 of 2 things that I fix often on the 500/550:

1. Leaking intake manifold O-rings at the head. They are the same size as the ones in the valve caps. The lowered vacuum at low engine speeds causes the engine to load up with fuel. The plugs in this situation will usually stay cleaner longer if the bike is mostly hiway-ridden (as a clue).

2. Spark advancer springs are heat-softened now, letting it advance too soon. This makes the engine 'spit back' at the carbs between about 1800 RPM (when the weights are already advanced, too soon) and 2800 RPM, causing the carbs to mix as if the engine were running at lower RPM, which is a richer mixture. A 'quick test' for this is to retard the whole points plate to the "T" mark(s) for the points and install new plugs, then ride it a bit (10 miles or so). If the plugs stay cleaner, it is definitely the springs. I removed no less than either: 1 full turn from one coil or: 1/2 turn from both coils, plus I re-shape the ends of the springs so they are not slack at the no-advance position.

With modern, slow-burning fuels, this problem is becoming much more frequent in the 500/550. Today's Midgrade burns slower than 1970s premium (in some areas, like here in CO, the Regular burns that slow) which makes it act even richer. Modern fuels burn very slowly so as to help light off catalytic convertors in cars and trucks.

Manifold gaskets were replaced.  Funny, I refrained from even mentioning anything about the ignition because I have seen a lot of members say "ignition has nothing to do with rich condition plugs."  But advance springs have always been in the back of my mind.  That's another part that should be about $5 that is impossible to get without buying an entirely new advance unit.  I do have a spare set of used springs, so I will do the test soon and see.  If it needs it, I'll clip em.  I honestly would suspect that before my needles/needle jets.

[Kenzo1979]

If I may add my experience with 022A carb set long time troubleshooting...

Noted.  Thanks for sharing that experience.  I will consider these things when I get into it soon.

[Kenzo1979]

I like to have an NOS needle & needle jet to use with an accurate wire gauge to fit into the NOS needle jet to compare with my used needle jet/emulsifier tube to see how much wear has occurred where the needle scrapes the top/inside of the needle jet nozzles,which is where the fuel flows upward past the taper of the needles and spills out to atomize before it enters the intake tracts.
I do the similar type measurement to the O.D. of the needle/taper to compare.
These items are very difficult to find in the OEM stock configuration,but well worth the search. 

Nice!

[Kenzo1979]

I do think it would be a reach for the needles/tubes to be worn, at least enough to cause the issue I'm having merely for the fact that the plugs are uniform across the board.  Would make more sense to have only one or some plugs rich or different levels of fouling across them...but who knows. 

[Kenzo1979]

This sounds like 1 of 2 things that I fix often on the 500/550:
...With modern, slow-burning fuels, this problem is becoming much more frequent in the 500/550. Today's Midgrade burns slower than 1970s premium (in some areas, like here in CO, the Regular burns that slow) which makes it act even richer. Modern fuels burn very slowly so as to help light off catalytic convertors in cars and trucks.

So, would running regular be recommended over mid or premium?

[seanbarney41]

I used o think it was worth while to run premium fuel (92/93 octane) in my sohc4's until I discovered it just soots up your plugs.  89 octane or less works much better...unless you have increased compression over stock.

[HondaMan]

If I may add my experience with 022A carb set long time troubleshooting  : CB550K K1, stock, 15k miles, engine never opened. Carb set was rebuilt by proffesional, all brass parts original Keihin (jets 38/100)

Advacer springs : at the beginning, I had general issue with all cyl (all black, bike felt as running rich on low-mid RPMs, while running well on mid-high). Hondaman adviced me to check advancer springs - I fixed that with replacement of stock advancer and points with electronic ingition from Boyer Bransden (has embedded advance curve inside ECU - mechanical advancer is removed). Since then, bike was running far better on low-mid, except cyl#2 - that was always black

To fix issue on cyl#2, (I ONLY had issue with #2), I tried all this w/o success : carbs re-cleaning (it was already very clean), float height check, valves adjustment, swap of coils from another bike, new plugs, leak test OK, compression test OK, new O-rings on manifold, 1-2 manifold replacement..
Then I gave up and bought another set (069) - surprise, issue gone from #2! But drawback was worse behaviour on slow-mid RPMs compare to 022A and impossible to sync for unknown reason. So I put 022A back and issue was back again on #2 cyl 

Start inspecting all every small detail on that #2 carb, I check also emulsification tube from inside and found it was quite corroded inside hole where needle goes, with missing "material", making hole rough and obviously bigger than other 3! (have a look on attached photo).

I only had available set of Keyster tubes at hand, replaced all 4 (needled kept original), did sync again and bingo! Issue was gone, no more black plug #2, engine silky smooth on low-mid RPMs! So combination of genuine Keihin needles and Keyster tubes works well. Later on bought genuine Needle/Emulsifier tube sets, replaced all of them and there was no difference, even no sync needed.

This took me 2 seasons to find root cause, now very happy with it

Note: Hondaman's advices are definitely to be considered as general to do/check first (Hondaman knows, we discussed that by email  ) => MANY THANKS Mark for all your advices!

Glad to help, Erny, and good job on sleuthing it!
That's a remarkable photo you've got there. I've seen that damage (from MTBE fuel erosion) before, too, more often in the 750 hi-mileage carbs that sat too long with water in their old gas, then got cleaned. The 750's needle jet is separate from the emulsifier, unlike the 500/550 that has both in one part.

[HondaMan]

This sounds like 1 of 2 things that I fix often on the 500/550:
...With modern, slow-burning fuels, this problem is becoming much more frequent in the 500/550. Today's Midgrade burns slower than 1970s premium (in some areas, like here in CO, the Regular burns that slow) which makes it act even richer. Modern fuels burn very slowly so as to help light off catalytic convertors in cars and trucks.

So, would running regular be recommended over mid or premium?

Most definitely, today. I run Regular in my 750 (and it has increased compression of 9.2:1) unless I'm out on the freeways a lot, or touring at full speeds all day (here in the American West that is 80+ MPH in most States). Then I will mix every-other tank with premium and midgrade. It all just burns too slow for the design of these engines, now.

[Erny]

Just thinking how it is my case, in Slovakia l with fuels. Most of the time running premium one (100 octanes) as it's "bio component" should degrade significantly slower than standard 95 octane E10 (this contains real ethanol). Now we have   10% (on reality 7-10) mandatory in fuels here

I did not observe some strange behavior, maybe except plug colors bit on lean side.

Still have plan to test with airplane Avgas 100LL fuel (still contains lead), but hard / not practical to get

[Erny]

I do think it would be a reach for the needles/tubes to be worn, at least enough to cause the issue I'm having merely for the fact that the plugs are uniform across the board.  Would make more sense to have only one or some plugs rich or different levels of fouling across them...but who knows.

Check advancer springs for sure - good strobo gun can show you if full advance is not coming much sooner than it should

[Deltarider]

Reading the advice on fuel, I'm pretty convinced US gas differs from Dutch. Here's an interesting thing. In the 70s Honda The Netherlands advised to run premium, in spite of the fact that back then octane, both in premium and regular, always has been higher than in the US and yes I know the difference between RON and MON. Running regular overhere was and is safe however: no risk of detonation. Any slower burning of either premium or regular is not known here. Why Honda The Netherlands advised to run premium, I don't know. Nowadays we face a dilemma. Regular is E10, whereas the 'designer' fuel Shell's V-power contains no alcool, that is: not up to yet. I know it says 5% on the pistolgrip at the pump, but that is, for some odd reason, to comply with European ruling. Whether V-power will contain alcool in the future, we don't know, so maybe that 5% on the pistolgrip is there as preparation. I like the V-power, it's a very clean fuel and I never needed to add anything for hibernation.
When the oldstyle gas was gone, I knew a mechanic who mixed avgas for his CB750, but no more than 1:40.
Now a tip for inspecting the needle jets. On the CB500/550s with the oldstyle Keihins, removing the floatbowls, is all what it takes to do the cleaning. You can even do it with the carbs in situ, provided you are already familiar with them.
After you have removed the main jets, open so to speak the throttle wide, so the jetneedles are up. Stick a wooden match, toothpick or whatever in the needle jet's hole from below, cant it and you can wiggle the needle jet (aka emulsion tube) out. Sometimes they just come falling down by themselves. Spraying some WD-40 at forehand may help. Now that you have the bowls removed, you might as well unscrew the slow jets for a quick inspection. Also check the tiny O-rings around the main jets now that you have them out. On assembly just push the main jets in, do not turn.
There's been a lot of emphasis in this forum on the cleanliness of the little holes in the sides of the emulsion tubes. When I cleaned mine (decades ago), I never noticed the difference. If all are blocked, it's a different story ofcourse. The tubes themselves must be free of whatever residu however. Usually one or two movements with a pipe cleaner will do. Do not use anything abrasive.
To the advice in other posts, let me add mine. Don't start with taking things apart. Diagnose first and we have tests for that. The advance of the ignition can easily be checked for correctness by using a strobe. Leaking O-rings between the manifold and the head can easily be detected by spraying brake cleaner there with the engine idling. After I replaced the 16 crossheads by allen, I can do all carb maintenance with the carbs in situ. Everything is quite easy to access. Personally I never needed ultrasonic treatment.