new phm 40 ns fitted

[Husky]

Fitted the carb and it works great . bought it from dellorto.co.uk.
I specified all jets plus needle float settings for them. The needle setting was wrong and float was standard PHM 18mm when I recieved it . Wonder if they even rejetted it didn t check jets . After discussions with my father he finally let me adjust float and I put it to a compromising 21 mm. AND it runs excellent.
So back again to the Float dilemma . Is it because the carb is tilted forward the Saturno is specced approx 24 mm float level? should I take it out again and bend even more even if it now seem ok? I m more than a a bit uphung in this now cause I have had so much trouble with my old carb. It had the classic too rich habbit run nice when cold and start spitting under acc when warm.(seem my old vs didn t close valve properly I saw after inspecting it.)
Regards Tom


Carburettor Float height, millimeters
PHBG 16 +/- 0.5
PHBL 24 +/- 0.5
PHBH 24 +/- 0.5
PHBE 18 +/- 0.5
PHF 18 +/- 0.5
PHM 18 +/- 0.5
VHB/Z/T 24 +/- 0.5
PHSB* 11 +/- 0.5
VHSA* 11 +/- 0.5
VHSB* 11 +/- 0.5
* PHSB/VHSA/VHSB one piece float assembly.

[garagien]

Dear Tom,

do you have only one petrol cock or both sides with cock (gives better flow). Unfortunately in German you will find some informations about carb adjustments under:
Garagien/SaturnoTuning/SaturnoTuning01.pdf

You will understand the word "Niveau". My best experience is with levels between 25 and 27 mm, but depending on engine specification.

Perhaps you will find some informations to handle with.

HP

[Husky]

I only have one. at least only one place to adjust.
I ll check the link thx.
Regards Tom

Edit: that was interesting to see all the different combos that divert quiet a bit from original. Not too hard to understand the German either just use some logic .
I guess now that I have a combo that apparantly work fine I don t mess with it again. If I set level to 24 mm the cock will barly open before the float is restricted from futher movement downwards.

what carb do you have? two petrol cocks? with niveau were talking about float level right? not actual fuellevel in the bowl? 27 mm seem unbelieveable.

Regards Tom

[garagien]

too many questions.
Niveau = float Level = distance between float cover sealing surface and bottom of float when float needle is just closing. Float needle has a little spring inside, you can move float against spring but needle is still close. So you measure just by weight of float when needle is closing and the little pin at top of needle is not moving. Understand?

If you have a standard 500 cc one cock might be ok. But we had 500 cc engines which are not working under top Speed. A second cock (instead of the level connection at right side) was the real thing using a Y-Connection from Guzzi at carb inlet.
Each engine has its own demand. Using 350, 500, 550, 560, 580, 600 or bigger volume engines you have to recarb again. My list is just to have an indication of a first start. I really have no same engine by cc with same carb adjustment. If you carb for street only is totally different as for race track use.

Based on my experience of the last 26 years we run Saturnos with two cocks as Standard to bring as much as fuel to the carb inlet. For instance the Guzzi cocks with M16x1 have a bigger connection inside dia than the original Saturno cocks. Even these cocks we drilled bigger to have more petrol going trough to minimize float losses. I do not want to make you nervous. I understood that you are on the right way. So go by yourselve.

HP

[Husky]

Thx I get your point, I ll try not to have a breakdown although not every detail is under 100 percent control . I got that part of the float resting but not pressing that light return spring.
Thx for help
Regards Tom

[Husky]

Dear HP . Do you know if float level also affects idle speed? Mine clearly runs best with only one turn at 1500-4000 rpms. My floatlevel is 23 mm now, and I also use long time before I can let out choke.
Regards Tom

[garagien]

Dear Tom,

if you google for ...dellorto manual...you will find minimum 4 different versions to download. I assume you already did.
Knowing nothing about other bikes is always a gamble.
But all I can say is that my engines will never work with only one turn out of the air needle. What is your jet size?
We adjust minimum 1,5 to 2 turns out with idle jet around 55 which is good for road use. But manual choke you can close at my engines around 100 to 150 m from start.
It seems that you still have a bug to look for.

HP

[Husky]

Hi again and thanks for quick answer HP.
my idle jet is 53 although I never checked they gave me as specified. I checked needle, main jet and acc pump . Its the area between 3500 and 4000 rpm with moderate acc it seems to wanna die out.I just put that fact together with the other behaviour ( idle 1 turn and needing choke 5 mins + a summerday)and try to remember physical laws also apply for my bike. I will try raise needle and see. and maybe go back to 22 mm float level. Change one thing at the time.
I got my jetsizes from downloaded saturnomanual. a bit difference fro Italy and Germany. I think mine is the german settings, but theyre quite similar as far as I can remember. And yes I read tons of stuff from Dellorto carbs hehe.
I also have my old VS and found what was wrong with it.The float never closed inlet valve at all because of some idiotic bending on the tap. Cant believe I didn t notice that earlier. In time I will rebuild it, so I have options.
Best regards . Thomas.

[Joachim]

if it's a standard Saturno it should run with the standard jetting given in the manual.
HP always is thinking about racing Saturnos first
Did you have a 'german' version or an italian?
If you don't know it can be testet at the exhaust outlet.
Thump.... italian
Finger... german

Sometimes there are converted versions out there.
Some people remove the little tube at the german exhaust damper and never modify the inlet rubber or/and the jetting.
I found this at several german Nordies converted from 27HP
So maybe it's worth to have a look.
You know the different jetting from the manual i think.
The rubber has to be fully open. In the german version there are some of the small rectangle parts closed.

If your Saturno is running fine on idle with the screw out only one turn, it should have either a to big idle jet and/or a wrong (to high) fuel level.
At least i would suspect this. But i may be wrong

ciao Joachim

[Husky]

Thx for answer. I ll try the finger thumb trick . I have german jet settings. At least thats what was on my vs so I assume its German version. It was in a link from hp I saw difference and there was a 145 mainjet there. Both Italian and German had 53 idlejet wich I now checked that I have.
Interesting what you say, that only one turn would mean too high fuellevel. wouldn t less air mean that the fuellevel was too low if higher level gives richer mix?
I have stock airfilter too.I use jettings specified in manual.


Best regards
Thomas

[Joachim]

Interesting what you say, that only one turn would mean too high fuellevel. wouldn t less air mean that the fuellevel was too low if higher level gives richer mix?

Maybe i'm wrong

If the level is to high, the idle system sucks to much fuel.
So you will have to turn the screw inwards.
But you also may be right.
Depends on how the idle screw works.
As far as i know on Saturnos it's regulating the amount of fuel (the mixture to be right)
There are systems where the amount of air is regulated.

Don't forget to check the rubbe rinlet of teh airbox if it's german.
If some oft he square holes are still closed, it's worth to cut them out, change tje main jet and de-germanise the exhaust damper
Gilera claims about 4HP for that
By the way, i did not know if that's road legal for the place where you live

ciao Joachim

[Husky]

Ohh I might have always misunderstood one thing then . I thought turning the screw out gave more air. Back to dellortomanuals:).
I ll check the squareholes .
Hmm road legal . As long as the papers are ok you nevver get trouble for a little extra noise
Regards Tom

[garagien]

not the idle system takes the fuel, it´s the underpressure of the engine. But idle system and main jet system are working together. Roughly 1/3 of revs is idling, the rest is main jet. If you have a "too big" idle jet you can reduce main jet size, it´s a tricky game. If level would have an impact all my engines would not work. The German setting is the worst in the world. Open air intake and muffler are important. Make idle jet and main jet slightly bigger and you will be happy (hopefully).
HP

[Husky]

Ok thank you very much for advices. Still I m not 100 percent sure wether turning the idle mix screw out gives more fuel or more air. Dellorto gives description of both systems. The phm 40 looks like the system that gives more air the more one turn out.
Inner diameter of my muffler end was 2,6 cm. I had no problem getting my thumb in there
One step at the time I ll end where I want to be. Thx .

Regards Tom

[Husky]

Just to "blog" an update
Tried a bit with the needle raised, and it did miracles to the dying out area between 3 a 4 k rpm. Thats the area I needed choke for.
This raising resulted in an increased idle rpm slightly and now it seemed 1 1/4 turn out was better than 1.
If turning out this idlemix screw gives more fuel, then I need to sit back and read "Zen and the art of motorcycle maitenance"...again..
Now gonna try with 21.5-22 mm floatlevel. Last time with 21 mm it was idling steady as a rock.( with 23 mm it had an +- 50 rpm fluctuation wich is not a problem in itself but I read it as an indication of something not being correct.
Thankful for all help I got . Hope you don t mind I type down my progression .
I m curious about that exhaust diameter though Joakim wich I meassured 2,6 cm. Possibly former owner put Italian exhaust and that might explain a lot. He is dead btw.
When I rebuild my VS I ll put other jettings following your excellent guide HP and use my KN filter(Is that what u ment with open airinlet HP?). Maybe even get a second nozzle.
Best regards Tom