PHBG tuning issue

[br4inl3ss]

thanks.
thanks for all that info.

first, before i forget... where thoes this passage goes ? (smallest one, to the left)


the intake is stock 139qmb one. i quess the naraku is made the same way but QUALITY material and manufacturing.
damn this shit is hard to remove what the hell.... had to "vulcanize", red-hot the damn rubber... and it wasnt enought had to wirebrush it lmao.

i re-verified that all passages are free flowing, both air and liquid (gas, acetone, vinegar).
they're all perfect but i'm questioning one.
it seems to go ont to the small hole under the slide, but under the carb we see its form and it goes way further.
also its not a straight passage because even tho it comminucate with the said small hole its not aligned to it. the passage is a bit to the left side but the hole is right in the center.
look the passage form i'm talking about. again the smaller one, at the bottom of the bowl area in the picture.


i dont see why they would make such a long passage if it stop at the small hole under the slide. but what do i know.
anyhow, this one is difficult to test properly i cant plug everything at the same time.
so MAYBE this one is clogged ?
thats the small hole under the slide (haha ofcourse not the jet hole).



the hose.. ill try to find something cheap. low budget and i ordered a needle set + i gotta replace the handlebar plastic holding the headlight. the fix i did isnt holding up and the plastic is cheaper than buying the required stuff to do a proper job lol.

i did check the fuel mix screw. it SEEMS in good shape.

UPDATE

i tested with the custom temp intake. no change. it wasnt an intake leak at all.

tested with a propane torch and see. no change at all. its blowing full speed. had to stop it was smelling propane in the whole garage.

also had to put back 32 idle jet its literally the only way for it to idle. its 1.5 or 2 turn out from fully seated. so this size is fine.

starting to thing i really need to mod my slide (i hsve 30 and it seems to be the smallest available) adding material so its a richer slide.

[cagiva4ever]

Hi !

bugger... No intake AirLeak then. good and bad news then...

quote:
-"first, before i forget... where thoes this passage goes ? (smallest one, to the left)"
photo QXjW3S6

iirc that is the Air passage for idle jet, as idle jet also works same as Main jet, both need/use Air emulsion. Some carbs have Long idle jets with integrated emulsion tube with air emulsion holes. some carbs just use "plain" short jet's and air delivery is kinda "fixed position" and rough.
Its same idea on other dellorto's too, so pdf's and some youtube vids show it on half cut open/hacksawd dellorto carb body. To get you on ritgh track here....


The "tiny odd" hole under Throttle slide is the fuel delivery into Venturi area/passageway for idle jet.

have you "shined a light" through it ? of course its difficult to capture it Via photo,as long as you yourself know how it is, clean and fully open.
Their not huge in Diameter, like 0,5mm "like a fine thread sawing needle". nothing couple mm's, as no need to be, due idle jet's commonly are from 0,25mm~0,50mm in Metric diamter (at dellorto's)

As a sidenote:

idle jet also works same as Main jet, both need/use Air emulsion. Some carbs have Long idle jets with integrated emulsion tube with air emulsion holes (commonly Mikuni's and their clones). Some carbs just "plain" jet's and air delivery is kinda "fixed position" and rough.

Jet lenght also has an effect into "static fule pressure-> how deep in fuel bowl it is-> means richer/leaner.



We will continue and go through detail by detail how your carb if set by factory, we shall verify all..... Check the Float Height/Fuel Level. Also in example: Any obvious eye visible misshappening on the "float tang" ? nothing diss-formed-whacked crooked....

Also tell us the intake Bakelite condition, as its now been dismantled at least 3x, and you have handled it. also its o-ring. After that Airleak is complitely ruled out...


at the very end if all is verifyd to be good correct, then there is not much left than swopping the needle and testing the CutAway at throttle slide....

[br4inl3ss]

the small odd hole under the slide is free flowing. i see light thru it and its a nice round hole.
i think the issue then is the idle circuit. because, even tho tis hard to test, it doesnt seems to communicate from the air filter hole to the idle jet. i cant see any light and cant see the wire strand either.
iirc liquid doesnt pass either.
so possibly its clogged there from factory between the odd hole in the ventiri and the idle jet.
that would mean Tomahawk the french moped god was right in his recent video when he said some batch of phbg had passages problem.

that would explain such small idle jet requirement AND my quick throttle problem. and so the choke way too rich issue.
no air (or not enought).

i flattened the modified intake to be sure its dead flat. i also put a new o-ring there after trying the stock one (normally very good seal since it works very good with stock crappy cvk carb) and had no change.

we can definitively says its NOT air leak. its 100% related to the carburetor. but what.
the more i look at it and read on the internet, if its not a clogged idle circuit, then its 80% chance the slide cutaway and 20% chance the needle.

if its the needle, fine. i have a set on th way. but if its not then another $$$ throwed by the window. and i cannot buy a slid because first $$$$$$$$ and second most importantly its the richest slide available. i have 30 and they only go higher number. like no 20 or 25. higher number iirc is leaner and i'm already too lean. so yeah thats a problem.

one thing i think forgot to mention, is when using a bigger idle jet than 34, i cant even up the idle speed. it bog down to death. 2000 is like the highest i can get yet its terrible all the way from 1500 to 2000+. the feel is like a main jet way too rich at WOT.

i'm sorry i jump from one thing to another. pretty hard for me to remember all shits and and stay focused on one thing for more than 30 seconds.

[cagiva4ever]

hi !

no problemo.

i own a Pro ultrasonic cleaner, and i always just Air compressor Blast the Passage ways too after u-sonic cleaner. but i also test blow air via small hose by my own breathing, to have a total tangible feel how passage way flows, that has always been fully enough as tests. as a hose size i use the same hose/size that is 2T oil injection hose.

i most likely have identical issue on my phbg 19ds racing (black body carb, aluminium topcap above throttle slide).
even that my mentioned carb is made like 10 years ago, not long time after the Product range was published for sale.

im using it on 2T , and you are in 4T, we have simulatirys and some differences on our carbs, and like previously explained, our Symphtoms accure differently due 2T vs 4T.

id say, that if Cutting out/causing bottle neck for Idle jet circuit AirEmulsion access, then it causes the "Collapse" effect, very rich idle mixture that varies, as the negative pressure/suction/pulse varies for the Air Delivery...


PHBG idle jet being this:
www.fruugo.fi/vaihto-30-52-messinkikaasuttimen-suihkut-1488-dellorto-phbd-mamb-uaub-phbg-idle-jet-m5thread-moottoripyoran-lisavaruste/p-289308753-645848179?language=fi&ac=croud&asc=pmax&gad_source=1&gclid=EAIaIQobChMI7eenhbLqhQMVnhiiAx1iJA0tEAQYBCABEgLZp_D_BwE


do you have these "welding nozzle cleaners" to fine hone the Air Passageway from carb body.

www.aliexpress.com/item/32838025414.html?src=google&src=google&albch=shopping&acnt=897-548-8760&slnk=&plac=&mtctp=&albbt=Google_7_shopping&gclsrc=aw.ds&albagn=888888&ds_e_adid=&ds_e_matchtype=&ds_e_device=c&ds_e_network=x&ds_e_product_group_id=&ds_e_product_id=en32838025414&ds_e_product_merchant_id=105181672&ds_e_product_country=FI&ds_e_product_language=en&ds_e_product_channel=online&ds_e_product_store_id=&ds_url_v=2&albcp=19366796298&albag=&isSmbAutoCall=false&needSmbHouyi=false&gad_source=1&gclid=EAIaIQobChMI9P2ewrLqhQMVwhiiAx1kHQ2mEAQYAyABEgIoGvD_BwE&aff_fcid=d6b55982822846dabb2f5dce00b17d57-1714495790580-05478-UneMJZVf&aff_fsk=UneMJZVf&aff_platform=aaf&sk=UneMJZVf&aff_trace_key=d6b55982822846dabb2f5dce00b17d57-1714495790580-05478-UneMJZVf&terminal_id=a1f327ebe2614f098fdd2833850fc2ad&afSmartRedirect=y

Torch Tip Cleaner Gas Welding Brazing Cutting Torch Tip Cleaner 14Pcs Set Guitar Nut Needle Files Nozzle Jet Drill Size 77-49


Ive had always multiple sets of those, and their Super good. Ive used them to upsize my modded "diy jets" on my china atv/airplane carb, which is using Welding nozzle jets as jets/and LPG gas jets (because m6x1mm thread)

The finest/smallest cleaner on that kit is solid/robust, even being very thin-tiny, all perfect and robust, flexible and will deffo grind material of from carb body too (aluminium alloy)


at the carb body, at the very "Mouth-opening" of the air passage hole, you can see the Brass color "insert" which is the pressed on "fixed size jet" , rest of the air passageway on the carb body until idle jet is juts the carb body aluminium tunnel-passageway. If you wont "hone" the "insert" you can hone up the carb body passage way slowly (just tape up-around the "cleaning wire metalfile" from area that touched "brass insert".


What do you htink about this ^^ ?

[br4inl3ss]

thanks.
everything is fine related to passages, even the brass insert as you call. perfectly round, light pass, liqide pass.
the place where it doesnt pass is between the idle jet "tunnel" and the hole in the ventiru we were talking about earlier.
i cant see light, i think the liquid wasnt passing either, and i cant see the wire strand at the end either.
like it was clogged. thats why i asked there this passage goes.
i have the phbg on the kitchen table again and ill recheck.
i found rubber hose so i can blow into the passage with my mouth instead of air compresor.


i was about to cancel the needle set order and borrow money to buy a PWK carb. those are known to work on 4 stroke, especially GY6 of all size. its even the first upgrade to do on 125/150cc GY6 engine.
a bit less popular on 50cc because the smallest PWK is 19mm and not that easy to find. others are generally 23 to whatever.
ive spotted some 19mm pwk on amazon tho...
but they're pita to fit there... larger intake connection, WAY larger air filter connection...
that means i have to buy a gy6 125/150cc intake or the naraku intake made for gy6 50cc as i have.

or a silicone coupler that doesnt seems to exist for those two size together but anyway.

EDIT

ok absolutly nothing is clogged.

used a craft paint bottle ( the ones with a needle you squeeze to get the acrylic paint out ) filled with acetone.
seating the needle on the smaller brass thing and it flow very good up to idle jet tunnel.

tester the bigger one, same it flow good.

then used a brush dont ask me where it comes from but it was similar to the one you were talking about: very small and hard enought to not bend for nothing. didnt find anything wrong.

EDIT 2

after searching the web once again, PHBG officially works on 4 stroke with NO issue at all.

confirmed by a shop that didnt vomit on the ground hearing "4 stroke" (very rare).

but only the AS model. i have DS. AS was way too much trouble mounting it because of intake mounting style and was very hard to get

here. the PHBG AS are made for 4 stroke 50-80cc.
so i compared specs....

same slide. only thing that change is the 3 jets (choke 55, idle 55, main 82) and the needle (W6).

thing is W6 isnt available in any kit i can get here.

all the kits have W3 W4 W5 W7 W8 W9 W10 W11 W12 W25.

i know there is no logic in needle naming, but you think i should be good anyway ?

duh idle jet that comes with it is even bigger than what came on my DS and its way too big. lol WTF ?

[thach2264]

I’ve almost same issue as you after 80cc bbk for my typhoon. Idle great but always bogged when throttle and if go slowly it can go up to 25%. Did all the usual check…idle main needle etc…


Well after $280 tips for the mechanic, it’s running as it should now. Damn guy dont want to tell me exactly how it was fixed. He mentioned that the float was not fully sealed something along those line. Because before, I though fuel was coming out of my intake because of a bad petcock, so I ignore it and just use manual shutoff.

I overlooked = $280.

So it was running too rich all these time because of the float bowl not properly sealed.

[br4inl3ss]

thanks. not my issue tho. literally the first thing i verified.

[cagiva4ever]

Apr 30, 2024 19:47:16 GMT -5 thach2264 said:

I’ve almost same issue as you after 80cc bbk for my typhoon. Idle great but always bogged when throttle and if go slowly it can go up to 25%. Did all the usual check…idle main needle etc…


Well after $280 tips for the mechanic, it’s running as it should now. Damn guy dont want to tell me exactly how it was fixed. He mentioned that the float was not fully sealed something along those line. Because before, I though fuel was coming out of my intake because of a bad petcock, so I ignore it and just use manual shutoff.

I overlooked = $280.

So it was running too rich all these time because of the float bowl not properly sealed.

Hi !

that sounds to be that "Float height was wrong". Float height/Fuel level was wrong. Float "tang" was bend in wrong position....
Or the Fuel valve was passing fuel INTO float bowl all the time way too much.


quote: -"float bowl not properly sealed"
This literally means just a O-ring or paper gasket between carb body and bowl. There would have been eye visible fuel leak outside carb body..

[cagiva4ever]

Apr 30, 2024 16:36:38 GMT -5 br4inl3ss said:

thanks.
everything is fine related to passages, even the brass insert as you call. perfectly round, light pass, liqide pass.
the place where it doesnt pass is between the idle jet "tunnel" and the hole in the ventiru we were talking about earlier.
i cant see light, i think the liquid wasnt passing either, and i cant see the wire strand at the end either.
like it was clogged. thats why i asked there this passage goes.
i have the phbg on the kitchen table again and ill recheck.
i found rubber hose so i can blow into the passage with my mouth instead of air compresor.


......

EDIT

ok absolutly nothing is clogged.

used a craft paint bottle ( the ones with a needle you squeeze to get the acrylic paint out ) filled with acetone.
seating the needle on the smaller brass thing and it flow very good up to idle jet tunnel.

tester the bigger one, same it flow good.

then used a brush dont ask me where it comes from but it was similar to the one you were talking about: very small and hard enought to not bend for nothing. didnt find anything wrong.

EDIT 2

after searching the web once again, PHBG officially works on 4 stroke with NO issue at all.

confirmed by a shop that didnt vomit on the ground hearing "4 stroke" (very rare).

but only the AS model. i have DS. AS was way too much trouble mounting it because of intake mounting style and was very hard to get

here. the PHBG AS are made for 4 stroke 50-80cc.
so i compared specs....

same slide. only thing that change is the 3 jets (choke 55, idle 55, main 82) and the needle (W6).

thing is W6 isnt available in any kit i can get here.

all the kits have W3 W4 W5 W7 W8 W9 W10 W11 W12 W25.

i know there is no logic in needle naming, but you think i should be good anyway ?

duh idle jet that comes with it is even bigger than what came on my DS and its way too big. lol WTF ?

Hi !

So now you can see Light through the empty passage way ? between idle jet and venturi area exit hole ? light peaking out both ways. 

imgur.com/PqaCVF6


Difference between W06 and W09 Needle is only the lenght/angle of Taper, and that is only 4mm difference lenght, and angle/diam diffeence 0,40. very id say tiny difference. id call it as a "fine tuning" rather than "sudden death",  i cant belive that its your carbs problem atm.

W06 is richer needle, from those2.

W09 2.50 1.40 20.00
W06 2.50 1.00 24.00

earlyer linked Needle size chart:
www.mopo.fi/tiedostot/Luistineula%20W.pdf


i tested Mahoosively different Needles on my earlyer mentioned ATV, and even then i dint get Radical differences... on my bikes etc ive never ever had need to change stock parts.... i kinda have good comparason data from some exact same engines factory made, as a "Complite bike model range" of mine uses all same engines but level of factory made tuning is different, so among the Model range there's like 5+ different Specced carbs, where same parts varie as we are talking here on your Topic. 

In your PHBG 19 DS ,if it ends up to be the needle in FAiL all fault, im super baffled surprised.
We shall find out that soonish, as your needle kit is on delivery...


as you are Drowing in fuel with larger Idle jet than #34 , it tells that PHBG19DS 4T model carb in 4T motor, the idle emulsion is rich, meaning that Air amount mixed into/with fuel is very little. it would need more Air mixed into the fuel at idle circuit, but that cannot be Adjusted as there is no Air Mix screw, and air passageway's Brass insert is "fixed solid size", and there would be need to test smaller idle jet to compensate ratio/emulsion ratio.
(i would not just yet hone the brass insert diy bigger in size diameter..before id have smaller idle jets in test)

Ali-X china jest's start from size #30 (different steps than genuine dellorto made ones)

"Carburetor Jets for MAMB UAUB PHBG Idle Jet M5Thread Motorcycle Accessories"
www.aliexpress.com/item/1005006025717396.html


We just have to keep ruling things out by doing tangible tests to get Tangible facts.


Keep in mind that Carb body's air passageway on idle circuit has a "T-junction" . Could there be casting flaw/debry at Junction causing "bottle neck" for air delivery.... ?
if we continue to hunt down/speculate this "urban legend" mentioned at beginning....


The old style "PHBG as" carbs from 80s 90s y2k never had like any issues like these common day DS models have.

old style the original1, which was used on honda monkey's ,tuning aftermarket
moposport.fi/kaasutin-phbg-18-as-4t-dellorto/



Money problem is issue here too like you said. cant just keep ordering parts... if money would not be object, id buy the small ali-x idle jets and the w06 needle, and hone the air passages, do the float height/fuel level checks. Nothing much to do after that. (Expect Leaner slide CutAway model, and the diy brass insert honing...)


When my mentioned "Black 19DS racing" issues appeared, i parked it into carage for later future, day like this, to get more info. as its a "toy bike" a mule, road illegal vehicle. This is reason why i stopped sorting it out back then. 
This is 1st time since or ever before, i have been able to talk about it with some1 else, with same origin/simular issues...

[cagiva4ever]

^^Previous post contains the post inside the Quote... my fail...


Here some reference photos of throttle slides:

#30
moposport.fi/luisti-30-phbg-dellorto/?gad_source=1&gclid=EAIaIQobChMIi5-5_sjshQMV01GRBR1niww1EAQYASABEgKsGfD_BwE

#40
moposport.fi/luisti-40-phbg-dellorto/

#50
moposport.fi/luisti-50-phbg-dellorto/?gad_source=1&gclid=EAIaIQobChMIi5-5_sjshQMV01GRBR1niww1EAQYAiABEgLAcPD_BwE

[br4inl3ss]

thanks alot.
y thats the slides i find. but i need smaller number if my problem is effectivly the slide. well thats what i inderstand from 4-5 hours of research on the subject.
lower number = richer slide. if thats right.
i have the 30. so cant buy richer slide, it doesnt exist.

for jets i have both kit, idle and main. smallest idle jet i have (also the smallest that exist) is the #30. thats the one that work best for idle richness issue. or was it 32... anyway 34 and under works without fully screwing in the mixture screw.

i didnt tought about drilling that brass thing. thats a solution if everything else fails.

by the way the phbg 19 DS is NOT a 4t model, its built with 4t emulsifier and sleeve (AN 262).
the phbg 19 AS is a 4t model. i didnt know that earlier everyone said to buy the DS. and the AS is pita to mount.
anyway its too late.

how can i know for sure there is NO debris/casting parts half clogging the air passages ? liquid is free flowing and air too but maybe its restricted to fuck up the "vacuum" but not pushed air ?
maybe i can drill the small brass "ball" they pressed in to seal those passage after they're done, check/unclog, and then seal it back with j-b weld. they do this fo fix low fuel flow in PWK carb on high performance 2 stroke scooter.

[cagiva4ever]

Hi !

ill read that Throttle slide size coding later. i cant atm remember how it goes, but i see you have Checked it.

There is both versions 2T and 4T from the old original "PHBG AS". Only differenze on the AN/AU262 and the Sprayer above it. rest iirc identical.

The "dellorto basic principals" PDF that i linked , iirc has explanation how the Vacuum/pressure behaves depening of a Throttle slide CutAway amount.
EDIT: i read the pdf again. it doesnt have explanations, sorry, some other book had-has them, cant atm remember what was-is the book...
Anyway, if i go it right, CutAway number bigger is Leaner mix, as Bigger throttle slide CutAway lessens/Decreases the Vacuum amount into idle circuit...

Yes, same as you got it, quote:
-"lower number = richer slide. if thats right."
-"i have the 30. so cant buy richer slide, it doesnt exist."

So , you would need #40 throttle slide CutAway, to get the idle Mix leaner Vs your #30. We are here trying to Lean out your Idle circuit. idle jet above #34 your engine was drowing in too much fuel..

So there are still options to fix the too rich Idle circuit of yours:
-Throttle slide CutAway version/si #40
-Idle jet #30 maybe
-stock Needle W09
-and last resort the idle air passageway's "brass insert" Honing sizeup...in a suitable combo with above parts.





quote:
-"how can i know for sure there is NO debris/casting parts half clogging the air passages ?"

Not really any eye visoble option for it or any borescope system, as talking so tiny passage.... But i think only option is to hand feel poke it/hon eit with the Welding tip nozzle cleaner, like ive explained previously.

-" If you wont "hone" the "insert" you can hone up the carb body passage way slowly (just tape up-around the "cleaning wire metalfile" from area that touched "brass insert"."

For this you would need the real exact linked nozzle honers/cleaner....
If there would be some debrys/bad casting at the "T-junction" , id say they hand honing tangible feel if theyr there-exist.

Like you mentioned, it will be the last try/trick to hone the "Brass insert" little bigger.....Before that 1st try the W06 needle and like #30 idle jet combo.
If that fails or before that, you have also option to "JBweld" material onto the Throttle slide CutAway (depening which1 was richer/leaner, less or more CutAway....im in a horry atm...)

[br4inl3ss]

thanks. wait a second.
so with the sldie cutaway we can lean the idle ?
then richen up throttle with a needle.

i tought id need to richen with a slide cutaway not lean it out lol.
my brain is smoking right now. thinking of that, thinking of everything at the same time...
and i got a job so yeah. this adhd man.... not easy to deal with that shit all day long.
took me just 45 minute to make a damn coffee this morning. i keep going to do something and 0.00000001 second later i'm already on something else i forgot about the previous thing lmao.

anyway... because i had to buy shits for the job, i have to delay the needles set a bit. 2 weeks. not cancelling the order i just wont pick it up at polaris stealership as soon at they receive it. sad.

[cagiva4ever]

hi !

ive been away from home (we both have been busy apparently..)

Any update now ?

Yes, iirc afaik correctly, Throttle slide "CutAway" has an effect into how effectively Fuel emulsion gets drawn/sucked/delivered into venturi area, BUT ONLY AT idle Circuit low throttle opening area.

iirc like i previosly wrote, Bigger "CutAway" lessens negative suction at idle/low r.p.m range. This would cause Leaner Mix-Less fuel.
This is explained on some book which name i dont still remember... Hopefully i dint get it wrongway around:
*Bigger CutAway=Leaner.
*Smaller CutAway=richer mixture

As its all based on how effectively the Negative pressure/suction draws Fuel through Emulsifier (In example AN262 emulsifier)
As i remeber it, Bigger "CutAway" lets more Air from AirBox into Venturi area, when at same time bigger "CutAway" weakens/lessens negative suction into Emulsifier, when talking about the low r.p.m's at Idle Circuit, and until at the Circuit progression change from idle into mainjet.

Carb function is Progressive, things dont work "Linear".

[br4inl3ss]

no news yet.
they called on friday saying needle pack arrived but i told them to keep them i will buy them but not right now.
on my first pay i have to buy work pants and other shit. and also give an account on a beautifull 2003 hyundai elantra. had many hyundai in my life and i wanted this specific model for so long. ill have one. only 248 000km so thats nothing at all. body is rought, need floorpan, but the structure is in good condition. nothing to do mechanically.
so yeah. this wont delay the needle pack much but it will ofcourse delay the 52mm bbk and crank and cam and gears for sure.
unless it broke... no reason to put a 39mm back so yeah. lol.