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Jet sizes for a 710/712

Posted: Sat Jul 18, 2020 6:57 pm
by ChickenPinz
What carb main jet size have people found is best in their 710/712?

Jim is rebuilding my carbs at this time, and he noted that they have "Euro 3" jets in them, which are apparently optimized for 3,000ft altitude. Wondering what people find works best for them.

Re: Jet sizes for a 710/712

Posted: Sat Jul 18, 2020 7:56 pm
by pcolette
Jim has rebuilt and re-jetted a number of carbs for me over the years. This is the standard setup that has worked well for me in Wisconsin.

Pinz Carb Jetting.jpg
Pinz Carb Jetting.jpg (44.18 KiB) Viewed 413 times

Re: Jet sizes for a 710/712

Posted: Mon Jul 27, 2020 9:17 am
by pinzinator
I'm sure my 710 is jetted correctly, but am curious now. Can someone post a link or photo as to where each of these jets is located in the carburetor?

Re: Jet sizes for a 710/712

Posted: Tue Jul 28, 2020 2:33 am
by Hotzenplotz
@pinzinator

the jets are located behind the cover
Image

the upper set are the idle jets, bottom are the main jets

Re: Jet sizes for a 710/712

Posted: Tue Jul 28, 2020 1:08 pm
by pcolette
IMG_3139.jpeg
IMG_3139.jpeg (341.03 KiB) Viewed 269 times

Re: Jet sizes for a 710/712

Posted: Tue Jul 28, 2020 3:02 pm
by pinzinator
The last 2 postings make it easy to verify. Thanks!

Re: Jet sizes for a 710/712

Posted: Fri Jul 31, 2020 4:42 pm
by pinzinator
My idle air jet and air correction jets were correct (230 and 130), but my idle jet and main jets were one size too small (55 and 135). Where can I buy 4 each of the correct sizes? Any recommendations?

Re: Jet sizes for a 710/712

Posted: Fri Jul 31, 2020 6:15 pm
by pcolette
I'd give Andre a call. SAV also lists jets on their site.

Re: Jet sizes for a 710/712

Posted: Fri Jul 31, 2020 7:02 pm
by ChickenPinz
pinzinator wrote:
Fri Jul 31, 2020 4:42 pm
My idle air jet and air correction jets were correct (230 and 130), but my idle jet and main jets were one size too small (55 and 135). Where can I buy 4 each of the correct sizes? Any recommendations?
When you say "correct" vs. "too small", are they "too small" for how you're using your truck and how it's configured?

Re: Jet sizes for a 710/712

Posted: Tue Aug 04, 2020 9:55 am
by pinzinator
I use my Pinz mostly at sea level on the road. When off road, it can vary from sea level to 5,000' or so. I don't tow or load the truck.
Changing to the correct jets may be a waste of money, maybe not, It runs good now.
I only need the idle jets and main jets. Mine are 55 and 135 respectively.

Re: Jet sizes for a 710/712

Posted: Wed Aug 05, 2020 1:49 am
by boeing7873
I have played with all fuel and air jets chasing poor idle to power transitions. My conclusion is, if you have 55-135 and your truck runs well, don't mess with them, as they are within specs. As carbs and gaskets get old, minor vacuum leaks develop, (ie shafts, choke covers, carb bases.. etc) and running a little richer makes it run a little better, paying the price in a little less mileage and more emissions. (My truck is running 60-140 and is obviously rich but runs well) Actually, I may have gone to 60-135 now, I forget.)
Idle jets are way more critical in making the truck run well, as you have to also adjust your four idle mixture screws.
High jets have not shown a significant difference in driving when changed between 135 and 140. But I have not checked spark plug colors since I changed them.

I have obtained my jets from this Italian shop. I have actually sent my carb bases to them for shaft work.

https://www.ebay.com/str/alfa1750scarburetorspartsstore

Re: Jet sizes for a 710/712

Posted: Wed Aug 05, 2020 1:51 am
by boeing7873
Watch out for early and late idle jet models, some have o-rings, others don't. I have posted in other threads the differences and correct version for my carbs.

Re: Jet sizes for a 710/712

Posted: Wed Aug 05, 2020 9:01 am
by pinzinator
You are probably right, if it isn't broke don't fix it. Leave good enough alone.

I like the carburetor site on EBay!