DUCATI TT and F1 FORUM
 
It is currently Thu Aug 24, 2017 6:32 am

All times are UTC - 5 hours [ DST ]




Post new topic Reply to topic  [ 3 posts ] 
Author Message
 Post subject: Jetting for altitude
PostPosted: Fri Jul 01, 2011 12:18 am 
Offline

Joined: Fri Jul 01, 2011 12:12 am
Posts: 3
I've moved from sea level to 8000 ft, and need to re-jet. I have a Laguna Seca with a Dellorto PHM40.

(I tried dropping the needle one step and that was no good. Then - duh - read the Dellorto tuning manual and they say "reduce the jet size")

I went to a bunch of local shops.. no one is familiar with Dellortos. One guy had a Kehin chart that showed a 25% drop in jet size. All in the end said - just play with it and read the plug.

I'd like to know if there is a chart from Dellorto, and if not, where should I start? down 25%?

How 'bout the idle jet?

Interesting, that the local knowledge says I might have to richen the idle jet some. WTFO?

Right now what's in it is 145 main & 75 idle.

Grazzi!!

Charlie


Top
 Profile  
 
 Post subject: Re: Jetting for altitude
PostPosted: Sat Jul 23, 2011 4:56 am 
Offline

Joined: Sun Nov 07, 2010 10:54 pm
Posts: 425
Location: Brisbane
Hello Charlie, I have no definate answer for you but the Mikuni chart will give you an idea. If it were me I'd try something like 135 and see. At 8000ft if it doesn't work just go a little from there. I don't think the dellorto info makes any suggestions for altitude? Graeme


Top
 Profile  
 
 Post subject: Re: Jetting for altitude
PostPosted: Sat Aug 06, 2011 9:55 am 
Offline

Joined: Fri Jul 01, 2011 12:12 am
Posts: 3
Here is where I ended up.. not as big a change as I expected, but a 150 mile ride & reading the plugs after showed that this was pretty close.

Slide: 70/1 (OEM = 60/1)
Main Jet Front Cyl: 145 (OEM = 148)
Main Jet Rear Cyl: 152 (OEM = 155)
Needle: K5 (Same as OEM)
Atomizer: 265 (Same as OEM)
Pilot Jet: 75 (OEM = 65)


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 3 posts ] 

All times are UTC - 5 hours [ DST ]


Who is online

Users browsing this forum: No registered users and 2 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group
Template made by DEVPPL