UK Karting - Notice Board (2-Stroke Karting) : Re: Rotax max Snr Needle position

Notice Board (2-Stroke Karting)

Re: Rotax max Snr Needle position
Posted by 'Bigjim1978' on 25 Jan 2011 @ 13:26

| View Message Thread | Reply to this message |

Bigjim1978Joined: March 2009
Total Posts: 1
[ View User Profile ]

Jetting software has to be calibrated to your engine and carb etc at the start anyway and until you have enough experiance to know what difference the jetting changes you are making have to the performance, the software isnt much use.
Im no expert and most certainly couldnt write an article on the subject but from what i understand the needle jet affects the mixture of the initial carb opening. To my mind you want this as lean as possible to make sure it comes off the corners nice and crisply. The mixture in the latter stages of the carb opening are affected by the main jet. This is normally where you notice fuel starvation/popping etc so you adjust this to suit the weather/track/engine on the day. Some people try lifting off slightly towards the end of the straight to richen the engine up.. if the engine accelerates your jetting is too lean. You can also try lifting the choke slightly which has the same effect. Once you have found the right jet for you and your engine it never changes by much. Maybe one or two bigger when cold or one or 2 smaller when hot. Software helps on a race day when you have it fully calibrated and temperature and humidity changes alot and you are looking for the last tenth or two!

Message Thread:

Rotax max Snr Needle position by 'mattkart' (22 Jan 2011 @ 21:20)

Re: Rotax max Snr Needle position by 'John' (23 Jan 2011 @ 1:08)

Re: Rotax max Snr Needle position by 'Simon43' (24 Jan 2011 @ 0:17)

Re: Simon43 by 'John' (24 Jan 2011 @ 8:10)

Re: Rotax max Snr Needle position by 'Bigjim1978' (24 Jan 2011 @ 9:44)

Re: Rotax max Snr Needle position by 'John' (24 Jan 2011 @ 10:21)

I thought you might John! by 'alanrr' (24 Jan 2011 @ 14:23)

Re: I thought you might John! by 'Newshound' (24 Jan 2011 @ 14:55)

Re: Rotax max Snr Needle position by 'mattkart' (24 Jan 2011 @ 18:16)

Re: Rotax max Snr Needle position by 'John' (24 Jan 2011 @ 18:21)

Re: Rotax max Snr Needle position by 'mattkart' (24 Jan 2011 @ 21:48)

Re: Rotax max Snr Needle position by 'John' (24 Jan 2011 @ 23:07)

Re: Rotax max Snr Needle position by 'Simon43' (25 Jan 2011 @ 10:55)

Re: Rotax max Snr Needle position by 'Bigjim1978' << You are here!

Re: Rotax max Snr Needle position by 'DrewB' (25 Jan 2011 @ 13:42)

Re: Rotax max Snr Needle position by 'Bigjim1978' (25 Jan 2011 @ 13:58)

Post a Reply:

You may post a direct reply to this message which will appear in this thread.
To post a new or unrelated message use This Form. Top of Page
Notice Board Index

[ UK Karting Main Index ]


News	Karts & Karting	Notice Board	Market Place	Companies Directory	Tracks Directory	Events Calendar	Race Results	Photo Gallery	Links