dellorto PHBG 21 mm carb setup

[david14a05]

How's the new engine? Done yet? Sorry about the motor bud.

I'm still in testing, currently at 96 main 42 idle. (I'm going to lean to a 94 today)
It's running good, but still too rich. Plug blackens at 1/2 to FULL throttle.

Here's something, The bike has always run smooth at WOT, (by smooth I mean vibration-free, clean-sounding burn, massive pull), but that's where it is still running the richest and blackening the plug. Then, at low rpm, it is just right, (i think) on which jet (42), but doesn't run as smooth as WOT IMO.
Maybe Tiba could share what he knows about this. I assume it is related to my taller gears as the bike tries to get moving.

I washed the bell and the clutch pads, and there is still a hint of vibe at low end, but it's much better, and haven't stiffened the clutch yet but will play with that next. What would happen if you loosened your clutch way down towards like 4000rpm? Is that more like a stunt-bikers setup? or, Would it lug and bog up to high rpm? Just curious as I am new to clutch settings, but do get much of the theory.

my engines fine now just had it rebored and bought a new piston since it had scratches on it but i dont think there was nothin wrong with it since i compared the piston rings. also what kind of carb, reed valve and needle do you have it might help me out. also im running stock gears, stock clutch, clutch bell, and belt. have you upgraded yours ? its just that might be what making mine go bruuuuuuurrrrrrrrr! all the way to 40-45mph then it shoots off like a rocket but its no good because its embarasing haha. in time i will upgrade everything but is just want to be able to ride it without the horrible noise and the constand full throttle up to 45mph to try and get it to go fast. i wander if my squish it to high? its at .56 atm

 

[BB Roxx]

my engines fine now just had it rebored and bought a new piston since it had scratches on it but i dont think there was nothin wrong with it since i compared the piston rings. also what kind of carb, reed valve and needle do you have it might help me out. also im running stock gears, stock clutch, clutch bell, and belt. have you upgraded yours ? its just that might be what making mine go bruuuuuuurrrrrrrrr! all the way to 40-45mph then it shoots off like a rocket but its no good because its embarasing haha. in time i will upgrade everything but is just want to be able to ride it without the horrible noise and the constand full throttle up to 45mph to try and get it to go fast. i wander if my squish it to high? its at .56 atm

I have the PHBG 21 mm DS (black racing version), VForce3 reed valve, stock PHBG carb needle. [ame="http://www.youtube.com/watch?v=9Qa8Lx3wRxA"]YouTube - Malaguti Build Up Parts[/ame]
Mine is very close now to being perfect. It snaps pretty good off the line but I think I could use a slightly lighter roller weight set as mine seems to take off strong after a second or two. Mine WAS taking until 20mph before it would open up like a rocket but that went almost completely away after I removed the restrictor ring that I installed. (the ring that came with the Malossi Overange transmission).
I suspect that your clutch is what's holding you back. If it is the stock clutch then it is set to engage much sooner than the EVO cylinder prefers. My clutch is a Malossi Delta which I set up with the lighter masses that it comes with, set in the original location. Then I swapped the white sport springs out and put in some MHR red ones. So my clutch is engaging at 8000 rpm, and the lag is gone from 5mph to 20mph. It's only the 0-5 mph that I need to fix now and if I can get that it will pull hard from moment of throttle crack all the way up to 80mph. Also I have the Kevlar belt and 13/44 upgear kit. I was thinking of going back to the stock gears to achieve low end snap versus top end speed for awhile, just for fun.

Tiba, I put some 110 octane race fuel in, however with little change in the sounds I'm hearing. So I guess that snapping sound might be carb noise vs. pre-ignition. As I move the throttle up from idle, it revs just a bit, then snap, snap, snap, snap, snap, snap, snap, then as it goes further up it clears to a nice clean sounding burn. I'll get a video of it today up on YouTube so you can try to hear it, but sound is always a little tough to translate once it's recorded and played back. Anyway I'll try to get an accurate recording of what I'm hearing. Being somewhat a Newb, sound is something I'm not too good at identifying.

 

[tiba_karotsu]

I have the PHBG 21 mm DS (black racing version), VForce3 reed valve, stock PHBG carb needle.
Mine is very close now to being perfect. It snaps pretty good off the line but I think I could use a slightly lighter roller weight set as mine seems to take off strong after a second or two. Mine WAS taking until 20mph before it would open up like a rocket but that went almost completely away after I removed the restrictor ring that I installed. (the ring that came with the Malossi Overange transmission).
I suspect that your clutch is what's holding you back. If it is the stock clutch then it is set to engage much sooner than the EVO cylinder prefers. My clutch is a Malossi Delta which I set up with the lighter masses that it comes with, set in the original location. Then I swapped the white sport springs out and put in some MHR red ones. So my clutch is engaging at 8000 rpm, and the lag is gone from 5mph to 20mph. It's only the 0-5 mph that I need to fix now and if I can get that it will pull hard from moment of throttle crack all the way up to 80mph. Also I have the Kevlar belt and 13/44 upgear kit. I was thinking of going back to the stock gears to achieve low end snap versus top end speed for awhile, just for fun.

Tiba, I put some 110 octane race fuel in, however with little change in the sounds I'm hearing. So I guess that snapping sound might be carb noise vs. pre-ignition. As I move the throttle up from idle, it revs just a bit, then snap, snap, snap, snap, snap, snap, snap, then as it goes further up it clears to a nice clean sounding burn. I'll get a video of it today up on YouTube so you can try to hear it, but sound is always a little tough to translate once it's recorded and played back. Anyway I'll try to get an accurate recording of what I'm hearing. Being somewhat a Newb, sound is something I'm not too good at identifying.

you could adjust the spring tensioner plate so the clutch engages at a higher rpm, that will take care of your 0-5mph lag, don't compensate the rollers for take off or launch, the rollers should only be tuned when it's moving, if it struggles to get up to speed when it's into the powerband only then you should tune the rollers. like i said before, start light then go heavier as required until you achieve your target.

snapping sound? it's either running too rich or too lean, have you adjusted the needle to see if it gets better or worse?

get a 15/42 secondary from Polini & put the stock primary gear on if you want something in between.

do you also have plenty of shims for the vario to set the belt ride height at the front pulley? you should add shims just enough so the belt barely touches the vario pin when the outer pulley is installed to give you the best take off.

 

[BB Roxx]

you could adjust the spring tensioner plate so the clutch engages at a higher rpm, that will take care of your 0-5mph lag, don't compensate the rollers for take off or launch, the rollers should only be tuned when it's moving, if it struggles to get up to speed when it's into the powerband only then you should tune the rollers. like i said before, start light then go heavier as required until you achieve your target.

snapping sound? it's either running too rich or too lean, have you adjusted the needle to see if it gets better or worse?

get a 15/42 secondary from Polini & put the stock primary gear on if you want something in between.

do you also have plenty of shims for the vario to set the belt ride height at the front pulley? you should add shims just enough so the belt barely touches the vario pin when the outer pulley is installed to give you the best take off.

If I wasn't sensitive to how busy life can be, I ask you to expand on all 4 of your last comments, especially the last one. If you have the time I wouldn't mind hearing more.

The snapping sound is probably something to which you would say "that's how an EVO sounds" and that I should quit worrying about it. LOL

I ran the 94 main and still on my 42 idle today, seems the same; haven't looked at the plug yet though.

It still has a hesitation right at take-off and I'm trying to figure that out. Rollers you say no, clutch maybe, choking or starving fuel right at throttle crack maybe, tall gear symptom maybe, hmmmmm.....

On that Polini secondary.... if I take out the 13/44 prime and replace with the Malaguti stock prime then it's alot of front tire lift at take off you think? And if I leave the stock prime and add the 15/42 Polini secondary it will be a nice in-between of my two current set-ups? Trying to see if I followed you correctly on that one.

Anyway it's all very interesting and I'm having a blast playing with it all.

 

[david14a05]

I have the PHBG 21 mm DS (black racing version), VForce3 reed valve, stock PHBG carb needle. YouTube - Malaguti Build Up Parts
Mine is very close now to being perfect. It snaps pretty good off the line but I think I could use a slightly lighter roller weight set as mine seems to take off strong after a second or two. Mine WAS taking until 20mph before it would open up like a rocket but that went almost completely away after I removed the restrictor ring that I installed. (the ring that came with the Malossi Overange transmission).
I suspect that your clutch is what's holding you back. If it is the stock clutch then it is set to engage much sooner than the EVO cylinder prefers. My clutch is a Malossi Delta which I set up with the lighter masses that it comes with, set in the original location. Then I swapped the white sport springs out and put in some MHR red ones. So my clutch is engaging at 8000 rpm, and the lag is gone from 5mph to 20mph. It's only the 0-5 mph that I need to fix now and if I can get that it will pull hard from moment of throttle crack all the way up to 80mph. Also I have the Kevlar belt and 13/44 upgear kit. I was thinking of going back to the stock gears to achieve low end snap versus top end speed for awhile, just for fun.

Tiba, I put some 110 octane race fuel in, however with little change in the sounds I'm hearing. So I guess that snapping sound might be carb noise vs. pre-ignition. As I move the throttle up from idle, it revs just a bit, then snap, snap, snap, snap, snap, snap, snap, then as it goes further up it clears to a nice clean sounding burn. I'll get a video of it today up on YouTube so you can try to hear it, but sound is always a little tough to translate once it's recorded and played back. Anyway I'll try to get an accurate recording of what I'm hearing. Being somewhat a Newb, sound is something I'm not too good at identifying.

WOW! you have some great kit there i might save up for a clutch and clutch bell ! and an overange kit. i was jumping all over the place when i first got my bike working and the pull and the speed on the new kit after running stock just feels amazing i am goin to try new reed valves on mine to see if that helps then if not im going to get new transmition bits.

cool vid!

 

[tiba_karotsu]

If I wasn't sensitive to how busy life can be, I ask you to expand on all 4 of your last comments, especially the last one. If you have the time I wouldn't mind hearing more.

The snapping sound is probably something to which you would say "that's how an EVO sounds" and that I should quit worrying about it. LOL

I ran the 94 main and still on my 42 idle today, seems the same; haven't looked at the plug yet though.

It still has a hesitation right at take-off and I'm trying to figure that out. Rollers you say no, clutch maybe, choking or starving fuel right at throttle crack maybe, tall gear symptom maybe, hmmmmm.....

On that Polini secondary.... if I take out the 13/44 prime and replace with the Malaguti stock prime then it's alot of front tire lift at take off you think? And if I leave the stock prime and add the 15/42 Polini secondary it will be a nice in-between of my two current set-ups? Trying to see if I followed you correctly on that one.

Anyway it's all very interesting and I'm having a blast playing with it all.

that 0-5mph lag is the clutch still engaging a bit too early, stiffen up teh clutch springs by adjusting the tensioner or using a stiffer clutch spring (blue) will solve that problem.

on the gearings you understand very clearly what i have said, stock gear ratio is 12,2:1, by using the Malossi 13/44 primary gear with stock secondary you have 10,4:1, using teh Polini 15/42 secondary with teh stock primary gear will net you 11,2:1 which is right between the stock & the gears you have on right now.

now if you use 13/44 primary with 15/42 secondary you'll get 9,4:1 which is probably too tall now for a 70cc.

anyway i have a video of the Beta Ark LC scooter i tuned using MHR Team 6T kit, you should try to emulate how this scooter runs at takeoff & top speed, this will be your benchmark. watch in high quality.

[ame="http://www.youtube.com/watch?v=edJFj3Rvb9M"]YouTube - MHR Beta Ark topspeed run[/ame]

a little race against a Yamaha 180cc 4stroke scooter.

[ame="http://www.youtube.com/watch?v=XDyU_TpCkQU"]YouTube - MHR Beta Ark 70cc vs Yamaha Mio 180cc[/ame]

 

[david14a05]

that 0-5mph lag is the clutch still engaging a bit too early, stiffen up teh clutch springs by adjusting the tensioner or using a stiffer clutch spring (blue) will solve that problem.

on the gearings you understand very clearly what i have said, stock gear ratio is 12,2:1, by using the Malossi 13/44 primary gear with stock secondary you have 10,4:1, using teh Polini 15/42 secondary with teh stock primary gear will net you 11,2:1 which is right between the stock & the gears you have on right now.

now if you use 13/44 primary with 15/42 secondary you'll get 9,4:1 which is probably too tall now for a 70cc.

anyway i have a video of the Beta Ark LC scooter i tuned using MHR Team 6T kit, you should try to emulate how this scooter runs at takeoff & top speed, this will be your benchmark. watch in high quality.

YouTube - MHR Beta Ark topspeed run

a little race against a Yamaha 180cc 4stroke scooter.

YouTube - MHR Beta Ark 70cc vs Yamaha Mio 180cc

wow amazing videos i got my scooter working today just finnishing off adjustments to the carb. i think my belt slips when i accerelerate |(maybe my standard thansmition parts arnt good enough. do you know any good torch controlers and clutches. thanks tiba

 

[BB Roxx]

that 0-5mph lag is the clutch still engaging a bit too early, stiffen up teh clutch springs by adjusting the tensioner or using a stiffer clutch spring (blue) will solve that problem.

Maybe I'll try the blue springs first, do both methods yield similar results?

on the gearings you understand very clearly what i have said, stock gear ratio is 12,2:1, by using the Malossi 13/44 primary gear with stock secondary you have 10,4:1, using teh Polini 15/42 secondary with teh stock primary gear will net you 11,2:1 which is right between the stock & the gears you have on right now.

I get it. Thanks for converting the ratios ahead of time. Useful numbers.

now if you use 13/44 primary with 15/42 secondary you'll get 9,4:1 which is probably too tall now for a 70cc.

My guess, yes, getting to the tall side, but think of the top end!

anyway i have a video of the Beta Ark LC scooter i tuned using MHR Team 6T kit, you should try to emulate how this scooter runs at takeoff & top speed, this will be your benchmark. watch in high quality.

Cool, that sounds similar to my Firefox now, possibly a little crisper at 0 rpm and up. My top end runs crisp, IMO, but my credentials on the matter are still being groomed.

[ame="http://www.youtube.com/watch?v=edJFj3Rvb9M"]YouTube - MHR Beta Ark topspeed run[/ame]

a little race against a Yamaha 180cc 4stroke scooter.

Nice sound, similar to mine.

[ame="http://www.youtube.com/watch?v=XDyU_TpCkQU"]YouTube - MHR Beta Ark 70cc vs Yamaha Mio 180cc[/ame][/quote] That was interesting to watch, for obvious reasons. I never heard the 4T back off the throttle either, SWEET!:winner:

 

[tiba_karotsu]

wow amazing videos i got my scooter working today just finnishing off adjustments to the carb. i think my belt slips when i accerelerate |(maybe my standard thansmition parts arnt good enough. do you know any good torch controlers and clutches. thanks tiba

yup standard transmission parts are no good for the setup you have, get a Malossi Overrange kit, Delta clutch, wing bell, lots of rollers & stiffer clutch springs, start getting serious with the tuning.

 

[tiba_karotsu]

Maybe I'll try the blue springs first, do both methods yield similar results?

I get it. Thanks for converting the ratios ahead of time. Useful numbers.

My guess, yes, getting to the tall side, but think of the top end!

Cool, that sounds similar to my Firefox now, possibly a little crisper at 0 rpm and up. My top end runs crisp, IMO, but my credentials on the matter are still being groomed.

That was interesting to watch, for obvious reasons. I never heard the 4T back off the throttle either, SWEET!:winner:

1) preloading the clutchsprings & using stiffer clutchsprings are 2 different things but teh goal is still the same which is to raise the clutch engagement rpm. use whatever clutch spring you have in the clutch & adjust the tensioner plate first until you max it out.

2) no problem, glad to be of help.

3) yeah it should go faster IF the engine has enough power to pull the taller gearings, if not then it'll go slower, this is fact.

4) i showed this video so you can have a comparison especially at the 0-5mph range, there is no lag in that scooter & i haven't finished tuning the vario yet as i was still 2g too light in that video.

we will be upgrading the cylinder from an MHR Team 6T 70cc to the MHR Big Bore 7T 77cc, the owner of that scooter who weighs like a horse jockey wants more acceleration from his scooter so i guess if you want more power there is no replacement for displacement.

 

[david14a05]

Hello. I just tryed to start my bike and it wouldnt fire.
So i took my spark plug out and noticed that the white indicator next to the iridium part had come lose so i took it off and the plug still wort spark ? any sugestions please. I might buy the ngk one next. That denso one might have been a dud.

Also i will get saving for them transmition parts tiba thank you very much.9||6

 

[BB Roxx]

1) preloading the clutchsprings & using stiffer clutchsprings are 2 different things but teh goal is still the same which is to raise the clutch engagement rpm. use whatever clutch spring you have in the clutch & adjust the tensioner plate first until you max it out.

2) no problem, glad to be of help.

3) yeah it should go faster IF the engine has enough power to pull the taller gearings, if not then it'll go slower, this is fact.

4) i showed this video so you can have a comparison especially at the 0-5mph range, there is no lag in that scooter & i haven't finished tuning the vario yet as i was still 2g too light in that video.

we will be upgrading the cylinder from an MHR Team 6T 70cc to the MHR Big Bore 7T 77cc, the owner of that scooter who weighs like a horse jockey wants more acceleration from his scooter so i guess if you want more power there is no replacement for displacement.

I was about to switch to the blue, when I thought, first I should preload the reds, to the max and see what they do before switching up. (great minds think alike), lol. So I did that and now the clutch hooks up at 9500 to 10,000rpm. Reds are prolly good with the right amount of preload.

Here's two vids where I tried to capture the sound of the engine at idle and slight throttling. Listen for the snap just up from idle. Is that sound normal? thanks Tiba.
[ame="http://www.youtube.com/watch?v=HQNEO5EnuC4"]YouTube - Engine Sounds[/ame]
[ame="http://www.youtube.com/watch?v=83FOzNKVELs"]YouTube - Engine Sounds2[/ame]

 

[david14a05]

I was about to switch to the blue, when I thought, first I should preload the reds, to the max and see what they do before switching up. (great minds think alike), lol. So I did that and now the clutch hooks up at 9500 to 10,000rpm. Reds are prolly good with the right amount of preload.

Here's two vids where I tried to capture the sound of the engine at idle and slight throttling. Listen for the snap just up from idle. Is that sound normal? thanks Tiba.
YouTube - Engine Sounds
YouTube - Engine Sounds2

what carb setup you got there bbrox mine sounds quite alot like that but when the wheels on the floor its rubbish because i havnt got my new transmition yet. nice work you've dont there !9||6

 

[tiba_karotsu]

ok i hear it now & there is nothing wrong with that, it's normal, what you're hearing is the reeds resonating at a certain frequency which makes that "snapping" sound off idle. if you put on an airbox to muffle the sound it will be a lot quiter even if you drill just a big enough hole so it's not restricted.

 

[BB Roxx]

ok i hear it now & there is nothing wrong with that, it's normal, what you're hearing is the reeds resonating at a certain frequency which makes that "snapping" sound off idle. if you put on an airbox to muffle the sound it will be a lot quiter even if you drill just a big enough hole so it's not restricted.

That's what I was thinking that it may be normal, but I absolutely wanted to see what you thought. Thanks for the reply on that, it was making me nervous.

 

[BB Roxx]

what carb setup you got there bbrox mine sounds quite alot like that but when the wheels on the floor its rubbish because i havnt got my new transmition yet. nice work you've dont there !9||6

My carb is the dellorto 21mm DS Racing currently running a 94 main jet, a 42 idle jet, and the needle in the second position. I turned up my idle speed screw so that it idles at around 2500 rpm. I have a cone-shaped paper and oil filter (like a K&N), and the V-Force3 carbon fiber reedcage. Manual choke cable mounted on the carter coverbolt that you can see in the picture below. Also you can see my air filter to the left.

 

[david14a05]

My carb is the dellorto 21mm DS Racing currently running a 94 main jet, a 42 idle jet, and the needle in the second position. I turned up my idle speed screw so that it idles at around 2500 rpm. I have a cone-shaped paper and oil filter (like a K&N), and the V-Force3 carbon fiber reedcage. Manual choke cable mounted on the carter coverbolt that you can see in the picture below. Also you can see my air filter to the left.

wow thanks! im running 48 idle, polini reeds, idle screw slightly out, needle running rich as posible, and a 98 main jet. Have you advanced your timing? also i need to buy some new needles because its running too lean. still waiting on the transmition parts though. i will learn how to upload photos on here when i have got the time :!

 

[BB Roxx]

wow thanks! im running 48 idle, polini reeds, idle screw slightly out, needle running rich as posible, and a 98 main jet. Have you advanced your timing? also i need to buy some new needles because its running too lean. still waiting on the transmition parts though. i will learn how to upload photos on here when i have got the time :!

Loading pictures=

A pic of how I advanced my timing from original: I elongated the stator mounting holes with a dremel and drill bit into ovals and rotated the stator plate to the advance side-counterclockwise just a titch. NDog1 (forum member) helped me on this one, but I would love to hear Tiba's thoughts on timing these Minarelli Evos, as I am thinking about adjusting it further to the advance side. I am worried that the operating temp will rise significantly though.

 

[tiba_karotsu]

it's ok to advance the ignition by a degree or 2 max, too much advance & the enghine will not rev & could possibly detonate. this is why i prefer inner rotor ignitions with digital cdi, it gives you max power at all revs by having the correct ignition timing for all rpms.

 

[david14a05]

Thank you for showing me how to upload photos bbrox. i will get some on here of my project when i have time. i advanced mine 14mm along the flywheel rim which it said on the kit instructions but it still not running perfect maybe it could be too much advance. i will try retarding it sometime and see if it runs smoother.

Tiba what inner rotor ignitions would you recomend and what about the stock water pump will they still go back on? or would i need to fit an aftermarket hot water pump.

Thanks guys for your help.