dellorto PHBG 21 mm carb setup

[david14a05]

hello does anyone know a way of setting up a 21mm carb with a polini evo 2 70cc cylinder. i have main jet sizes 72, 82, 89.92, 98, 105.
i have tryed alll of these and tryed adjusting my mixture screw and it still doesnt rev right.

i have also ordered every jetsize from 70 to 105.

any sugestions please?

maybe i need a different pilot jet or needle?

Thank you for replys.

 

[BB Roxx]

I run an EVO2 with the 21 mm DS Racing carb currently with a 98 main and a 48 idle.
They are too strong cuz the other day when I was forced to putt, putt around in stop and go traffic I fouled the plug.

Originally I had in a 100 main and a 50 idle and it fouled plugs at wide open throttle or putt,putt speed.

now it runs alot better but still too much gas.

I'm going to put in a 95 main and 45 idle in about 10 minutes. let you know how that goes tomorrow.

 

[david14a05]

I run an EVO2 with the 21 mm DS Racing carb currently with a 98 main and a 48 idle.
They are too strong cuz the other day when I was forced to putt, putt around in stop and go traffic I fouled the plug.

Originally I had in a 100 main and a 50 idle and it fouled plugs at wide open throttle or putt,putt speed.

now it runs alot better but still too much gas.

I'm going to put in a 95 main and 45 idle in about 10 minutes. let you know how that goes tomorrow.

please send me a link were i can buy your from plug my bikes almost same as yours. i have no idea what plug to buy. you have same cylinder as me and i cant find a champion c53 anywhere. chears buddie.

 

[tiba_karotsu]

you can use an NGK BR9EIX or Denso IW27.

BB Roxx by the looks of your plug you need to run a leaner jet than 95, leave the 45 pilot for now until you get the main jet correct.

water cooled cylinders tend to run the strongest with leaner settings.

 

[BB Roxx]

you can use an NGK BR9EIX or Denso IW27.

BB Roxx by the looks of your plug you need to run a leaner jet than 95, leave the 45 pilot for now until you get the main jet correct.

water cooled cylinders tend to run the strongest with leaner settings.

Thanks Tiba, I think so too. That photo was the 48 idle/98 main. This photo is still 98 main but with 45 idle.

I'll post a new shot with 45/95 soon.
Thanks again

 

[tiba_karotsu]

you can't rely on plug chops when tuning the pilot jet, you do it by feel, it should have a nice clean crisp throttle response from idle to 1/4 throttle, the needle clip position & thickness also has an effect on that range.

for main jets it's only during wide open throttle.

 

[BB Roxx]

Been Playin'

you can't rely on plug chops when tuning the pilot jet, you do it by feel, it should have a nice clean crisp throttle response from idle to 1/4 throttle, the needle clip position & thickness also has an effect on that range.

for main jets it's only during wide open throttle.

So, I was playin around with different settings today and to tell ya the truth, all of the changes seemed to have little effect on the current performance of the machine.

• Started the day at 98 main - 45 idle - needle clip in the second position.
• Next I went out with 98 main - 45 idle - needle clip in the third position
  • (very little change noticed)
• Next I went out with 96 main - 45 idle - needle clip in the third position
  • (still very little change observed, overall less clean in the pull I think, but hard to tell for sure).

Did some chops while i was out.
With needle in the third pos. and a 98 main, the plug looked to be getting dark faster again, like when I was running 100 main and 50 idle.


Then with a 96 main same thing, WOT for a snap, but this time it looked to be cooking off the blackness from before; hard to say to what extent.

Overall I'd say that I learned very little today. The midrange pulls like a mofo with either clip position but with it in the second position, it seemed a little more intense of a pull. Low end is hard to tell cuz it seems to rev ok til the clutch grabs, and then it's a steady rpm, but low, do to the rollers I figure, until 20 m.p.h. and then you'd better hold on, cuz from there on up, it's a clean, vibration-free, torque-intense, acceleration to the top.

:winner:

So here is how it goes, twist throttle, engine revs to 6500-7000-7500 and then the clutch starts to grab, the bike starts to move, I pull my feet up, suffer through a loud, steady, low rpm up to 20mph, then it vibrates a bit; for a couple seconds, and then it cleans up nice and pulls like a raped ape up to 57mph and levels off. That's cuz I put the Overange restrictor in it for now, to keep me from going nuts right away.

Cheers
Roxx

 

[tiba_karotsu]

i think you raised your needle a bit too rich, bring the clip back to the #2 position, dellorto carbs tend to run rich from the factory. have you got anymore jets like 94 92 & 90? you sould have a nice light brown color from where the metal shell meets the ceramic insulator of the plug.

by the sound of it you need to lighten up your rollers & stiffen up the clutch springs.

 

[BB Roxx]

i think you raised your needle a bit too rich, bring the clip back to the #2 position, dellorto carbs tend to run rich from the factory. have you got anymore jets like 94 92 & 90? you sould have a nice light brown color from where the metal shell meets the ceramic insulator of the plug.

by the sound of it you need to lighten up your rollers & stiffen up the clutch springs.

Thanks for the tips tiba, ya I think I'll try that next. I got 100,98,97,96,95,94,93,92,90,.....80. definately going back to #2 clip to see if I was right about the crisper pull. The acceleration is wicked once it hits the powerband and that little vibration quits. Got any ideas on the vibration when its down low? Belt not running clean on the pulleys? I'm stumped.8P

 

[tiba_karotsu]

most likely it's the clutch grabbing the bell, try to clean the bell where the clutch pads make contact, use sandpaper & dishwashing liquid, make sure the clutch pads aren't contaminated with grease, if so clean it with dishwashing liquid & water. use 3M scotchbrite pads.

then try setting the clutch to engage higher in the revs, should be at least 8000rpm

 

[BB Roxx]

most likely it's the clutch grabbing the bell, try to clean the bell where the clutch pads make contact, use sandpaper & dishwashing liquid, make sure the clutch pads aren't contaminated with grease, if so clean it with dishwashing liquid & water. use 3M scotchbrite pads.

then try setting the clutch to engage higher in the revs, should be at least 8000rpm

Cool, alright, I'll check that.

Hey! On a side note, what's a good price for a stock 2004 Aprillia 1000, with 6000 miles on it, in US? Got any idea?

 

[tiba_karotsu]

Cool, alright, I'll check that.

Hey! On a side note, what's a good price for a stock 2004 Aprillia 1000, with 6000 miles on it, in US? Got any idea?

i don't know actually, Aprilias are exotics over here & it's rare to see one on the, you'll have more luck running into Ducatis than Aprilias.

RSV1000? they have some models like the Factory & so on, what model is it you're looking at?

 

[BB Roxx]

i don't know actually, Aprilias are exotics over here & it's rare to see one on the, you'll have more luck running into Ducatis than Aprilias.

RSV1000? they have some models like the Factory & so on, what model is it you're looking at?

Pretty sure the gal who owns it said it was a RSV1000 R. Does that make sense?

 

[tiba_karotsu]

Pretty sure the gal who owns it said it was a RSV1000 R. Does that make sense?

there are 2 models in the RSV1000 line up, the R is the basic version & then there is the "Factory" which has some refinements over the basic R model like the following;

* Radial calipers
* Fully adjustable Ohlins fork
* Adjustable Ohlins shock absorber
* Ohlins steering damper fitted as standard
* Forged aluminium wheels
* Rider's saddle with nonslip racing seat
* Matt black painted frame
* Carbon parts

if you have the $$$$ get the Factory over the R model, here's some pics.

basic R

Factory

we are way off topic now, lets get back to tuning carbs.

 

[BB Roxx]

there are 2 models in the RSV1000 line up, the R is the basic version & then there is the "Factory" which has some refinements over the basic R model like the following;

* Radial calipers
* Fully adjustable Ohlins fork
* Adjustable Ohlins shock absorber
* Ohlins steering damper fitted as standard
* Forged aluminium wheels
* Rider's saddle with nonslip racing seat
* Matt black painted frame
* Carbon parts

if you have the $$$$ get the Factory over the R model, here's some pics.

basic R

Factory

we are way off topic now, lets get back to tuning carbs.

Yes, carbs! Thanks for the reply though. It is just the basic R. 2004, stock with 6000 miles on it, she's askin $7000. But back to carbs, gotta go to work, then later tonight might work on the scoot.
TTYL (Talk To You Later) my friend.

 

[david14a05]

hey guys i found that information about bottom end carb setup very usefull since i am going to try and tune my carb in at the week end. mine is running very lean at the minute. do you guys know anywere in the U.K. that sells idle jets for dellorto phbg 21mm ? how many different sizes would yous recomend i buy ? i already have jet sizes 70 ....to...... 105. 9||6

 

[tiba_karotsu]

the main jet is different from the idle jet especially on the PHBG21 carb, usually the PHBG21 has a 50 idle jet, get a 45 42 & 40 size.

my friend has bought a used Beta Ark LC scooter with Polini Evo1 LC kit, PHBG21 carb & DPR C30 pipe, i'm currently running a 72 main jet, 50 pilot jet & the needle in the #1 clip position (leanest). this is with the stock airbox on & a 13mm hole drilled by the side of the intake snorkel.

the airbox reduced the noise from the carb significantly, even at full throttle the exhaust is decently quiet.

 

[trueOverrev]

the other beta will do all the noise part! :cheers:

 

[david14a05]

i ordered those idle jets tiba and a denso spark plug i hope my bike works soon

 

[tiba_karotsu]

i ordered those idle jets tiba and a denso spark plug i hope my bike works soon

good luck to you, take your time with it don't rush things, it takes time to develop a sense & feel for tuning 2strokes, it's both science & art.