Currently Offline
Posts: 0
Likes:
Joined: Nov 22, 2024 12:32:34 GMT -5
|
Post by Deleted on May 31, 2016 8:28:43 GMT -5
Hi, I dont know if my pilot jet is too small or too big!? My scooter have better acceleration with the mixture screw at only ¼ turn open!  ?[/b] Is it normal? When i read forum the mixture screw need to be at least 1½ open... If i close completely the screw motor turn faster, but ½ open too 2 turns open, no difference!? If i put at ½ or 1 turn open, hard to have stable idle and power cut between half to full throttle. The pilot idle jet (#35) it's the original. I have a Piaggio Typhoon 2013 (all original), 4 stroke 4 valve, carburetor cvk 20mm. |
|
|
|
Post by lain on May 31, 2016 9:53:55 GMT -5
#35 is the correct size, They don't range much, biggest idle jet I've ever seen in a carb even on a larger 150cc was only 37 and the smallest I've ever seen was a 34 on a moped from the early 90s... The mechanics behind scooters really haven't changed for over 50 years.
Acceleration is not part of the idle though, the diaphragm in the "acceleration pump" and the needle/needle diaphragm are responsible for acceleration and above idle. The main jet is responsible for about 2/3+ of the throttle. Idle jet is only responsible for idling.
By the way you describe it, it could be the needle diaphragm. Check for cracks, tears, dirt or hardened/dry diaphragm.
|
|
|
|
Post by JerryScript on May 31, 2016 12:22:11 GMT -5
Sounds like you may have a restriction in your air intake. 1/2 turn means the pilot jet is too rich for the amount of air coming in.
|
|
Currently Offline
Posts: 0
Likes:
Joined: Nov 22, 2024 12:32:34 GMT -5
|
Post by Deleted on Jun 1, 2016 7:57:50 GMT -5
What happen if i downsize the carburetor?
I have a brand new KEIHIN carburetor where i can adjust the mixture screw and the needle inside the carb but it's a 19mm!
If i compare of the original 20mm carb and i can't do nothing beacause it sealed!!!
Did i transfer my jets (#72) or need to put smaller jets in the 19mm carb?
|
|
|
|
Post by pistonguy on Jun 1, 2016 8:45:29 GMT -5
#35 is the correct size, They don't range much, biggest idle jet I've ever seen in a carb even on a larger 150cc was only 37 and the smallest I've ever seen was a 34 on a moped from the early 90s... The mechanics behind scooters really haven't changed for over 50 years. Acceleration is not part of the idle though, the diaphragm in the "acceleration pump" and the needle/needle diaphragm are responsible for acceleration and above idle. The main jet is responsible for about 2/3+ of the throttle. Idle jet is only responsible for idling. By the way you describe it, it could be the needle diaphragm. Check for cracks, tears, dirt or hardened/dry diaphragm. C'mon man lets get this guy started with correct information. The Pilot jet and mixture screw sure do have a lot to do with acceleration, They and the others Transition into the next circuit and supply fuel with just a smaller percentage. Here is a good diagram and there are a ton out there of the same thing showing throttle position and how much each circuit supplies fuel, You can clearly see the Pilot and Mixture screw are still doing more than we think at WOT.  Each Circuit must be correct to transition into the next circuit, if the Bottom end aint right the top never will |
|
|
|
Post by JerryScript on Jun 1, 2016 9:16:38 GMT -5
Most likely the jet that comes with the 19mm will be fine. If not, your best bet is to get a jet kit, they can be found relatively cheap with a quick google search. Much better than the frustration of returning to the store or re-ordering different sizes till one works.
|
|
Currently Offline
Posts: 0
Likes:
Joined: Nov 22, 2024 12:32:34 GMT -5
|
Post by Deleted on Jun 1, 2016 16:07:17 GMT -5
I have a other pilot jet in stock #33 and #32. I check the needle diaphragm and IS NOT ADJUSTABLE!!!!! I try a othe needle with adjustable clip, but the motor running very bad. The adjustable needle i have was to thin compare to the original one. I want thank you all for your help, very appreciate, i know my english is not very good, i speak french! |
|
|
|
Post by JerryScript on Jun 1, 2016 21:43:16 GMT -5
Your English is very good. My French is Tre repugnant. We will work through any language issues, all we care about here is riding and smiling!
|
|
Currently Offline
Posts: 0
Likes:
Joined: Nov 22, 2024 12:32:34 GMT -5
|
Post by Deleted on Jun 4, 2016 18:36:28 GMT -5
Ok
I find the problem !!!!!
The wire for the electric choke was cut in near the frame so the choke did't work!
Now i need to find why is not peppy in acceleration...
Thank's.
|
|
