dellorto side draft tuning questions

Mateepay · 11-15-2011, 09:03 PM

i have a dellorto side draft that was on my sp 12a had 147k miles when i lost rear rotor compression. when i pulled my motor to replace it with a recently purchased low miles motor i noticed the rear housing exhaust port was very white and the front was black. im assuming from general knowledge that my rear housing was running leaner than the front hence the failure. i am running two different sized jets front was 220 and the rear was 230 if i remember correct.

im curious on some input i would like to keep the motor lasting as long as i can this time around.

t_g_farrell · 11-16-2011, 08:50 AM

Theres no reason those jets should be different. I would check the jetting
at this site and compare what you have and verify its in the ballpark for the
new motor. I'm assuming the new one is SP as well?

www.gruntled.com/Dellorto

You may also want to rebuild your Dell as it could be a block idle mixture screw
or some other passage clogged with debris. Go to this site for your rebuild needs:

www.dellorto.com

They are in england but ship fairly quickly and can help you if you have questions.

Mateepay · 11-16-2011, 09:57 AM

Well I rebuilt the card with a kit supplied by dellorto on my last motor it was only on for maybe 3-4k. My delema is I'm very new to carburator tuning and have had no success. I've read quite a bit on the grunted site I guess that should be my best bet on tuning? And yes it is stock port I also forgot to mention I'm running a full street port racing beat exhaust

PercentSevenC · 11-16-2011, 11:56 AM

Cross jetting without dual wideband/EGT sounds like a bad idea to me. I'd start by setting everything the same between the front and rear rotors.

Mateepay · 11-17-2011, 12:35 AM

Sweet I will give the advice a try t g farrell much appreciated : percent seven c I will order the correct jets and give that a try

Thanks again for the fast and knowledgeable responses

11-15-2011, 09:03 PM	#1
Mateepay Rotary Fan in Training Join Date: Jun 2010 Location: tulsa, ok Posts: 71 Rep Power: 15	dellorto side draft tuning questions i have a dellorto side draft that was on my sp 12a had 147k miles when i lost rear rotor compression. when i pulled my motor to replace it with a recently purchased low miles motor i noticed the rear housing exhaust port was very white and the front was black. im assuming from general knowledge that my rear housing was running leaner than the front hence the failure. i am running two different sized jets front was 220 and the rear was 230 if i remember correct. im curious on some input i would like to keep the motor lasting as long as i can this time around.

11-16-2011, 08:50 AM	#2
t_g_farrell Waffles - hmmm good Join Date: Aug 2008 Location: Huntersville, NC Posts: 757 Rep Power: 0	Theres no reason those jets should be different. I would check the jetting at this site and compare what you have and verify its in the ballpark for the new motor. I'm assuming the new one is SP as well? www.gruntled.com/Dellorto You may also want to rebuild your Dell as it could be a block idle mixture screw or some other passage clogged with debris. Go to this site for your rebuild needs: www.dellorto.com They are in england but ship fairly quickly and can help you if you have questions. __________________ 1980 GS stockport, Fat Nikki, RB Dual Facetfuel pumps, Holley regulator, RB Street port exhaust, 2GDFIS, MR2 MK I electric fans, 2G strut bar, relayed fans, lights and fuel pump, LEDs Project Fat Nikki Budget 12A rebuild Video setup < $30.00 Last edited by t_g_farrell; 11-16-2011 at 08:53 AM.

11-16-2011, 09:57 AM	#3
Mateepay Rotary Fan in Training Join Date: Jun 2010 Location: tulsa, ok Posts: 71 Rep Power: 15	Well I rebuilt the card with a kit supplied by dellorto on my last motor it was only on for maybe 3-4k. My delema is I'm very new to carburator tuning and have had no success. I've read quite a bit on the grunted site I guess that should be my best bet on tuning? And yes it is stock port I also forgot to mention I'm running a full street port racing beat exhaust

11-17-2011, 12:35 AM	#5
Mateepay Rotary Fan in Training Join Date: Jun 2010 Location: tulsa, ok Posts: 71 Rep Power: 15	Sweet I will give the advice a try t g farrell much appreciated : percent seven c I will order the correct jets and give that a try Thanks again for the fast and knowledgeable responses