Carb jetting

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pinzinator
Posts: 917
Joined: Thu Jul 29, 2004 3:12 pm
Location: Indio, California

Carb jetting

Post by pinzinator »

Has anyone ever come up with an ideal carb jetting (0-5000')? The more I read about it, the more confusing it becomes, because there seems to be so many possible combinations. Depending on where you read, the combination may be different for the same conditions, such as sea level with a 710 or a 712 in the tropics. There are 4 jets that vary, as the starter jet and pump jet never change. Here's one chart I found for a standard 710-
Main jet- 125 (can go as high as 140)
Air correction jet- 170 (have also seen 230)
Idle jet- 55 (or 60)
Idle air jet- 110 (or 130)
My Pinz runs OK, but I like to tinker and wonder if anyone has the right combination. I'm sure there are a lot of opinions.
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pcolette
United States of America
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Joined: Sun Dec 10, 2006 7:38 pm
Location: Southwest Wisconsin

Re: Carb jetting

Post by pcolette »

This is what I'm currently running on one of my 710's:

MAIN JET 140
AIR CORRECTION JET 230
IDLE JET 60
IDLE AIR JET 130

This was set up for me by Jim LaGuardia and runs very well. I'm at about 1100' elevation.

Also had this setup on another 710 and it ran well too:

MAIN JET 140
AIR CORRECTION JET 170
IDLE JET 55
IDLE AIR JET 110

The only problem I ever had was when I had 125 main jets and the Pinz had a definite lack of power on hills. (more than usual that is) :)
Paul C.
_________
'73 Swiss 710M
'89 Puch 230GE
krick3tt
Posts: 2457
Joined: Thu Mar 16, 2006 6:48 pm
Location: Denver, CO USA

Re: Carb jetting

Post by krick3tt »

The issue with a carburetor is that the higher one gets in altitude the less oxygen there is. Mine runs fine at +5000 ft alt. but as I get up to 10 to 12,000 feet going across the mountains it loses power.
Can't tell you offhand what it is jetted for but it runs different at sea level so I am set up for Denver altitude.
Any man who thinks he can be happy and prosperous by letting the government take care of him:
better take a closer look at the American Indian.---Henry Ford
pinzinator
Posts: 917
Joined: Thu Jul 29, 2004 3:12 pm
Location: Indio, California

Re: Carb jetting

Post by pinzinator »

I have a spare set of carburetors. Here are pictures of disassembly and assembly afterward, something I like to do for fun. The Zenith 36 NDIX is just a puzzle like any other car part, 11 minutes elapsed between photos.
Everything was soaked in carb cleaner and then blown out with compressed air. Not shown is the new gasket kit.

Image

Image
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Jimm391730
United States of America
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Joined: Wed Apr 14, 2004 10:58 pm
Location: Idyllwild, CA

Re: Carb jetting

Post by Jimm391730 »

...11 minutes elapsed between photos.
How long does it take to put together when blindfolded, in the dark, and wearing mittens? :lol:
Jim M.
712W and 710M
pinzinator
Posts: 917
Joined: Thu Jul 29, 2004 3:12 pm
Location: Indio, California

Re: Carb jetting

Post by pinzinator »

Jim has a good point. The Zenith carb has about 90 parts if you include every nut and washer. When I refer to the carb as a puzzle, I only disassemble to about 50 parts. These 50 can be re-assembled in just a few minutes, and that is without installing the 2 main gaskets. If I were to put a Zenith carb together with the intention of actually installing it in my Pinzgauer, it would take much more time due to the care and precision that must be considered.
I recommend to anyone who has a spare carburetor to take it apart and put it back together a few times. It doesn't take long to get familiar with everything. Read the manual and you will begin to understand more just how it works, which isn't really that complicated. The trick is getting two carbs syncronized and working together, and that isn't something I can advise on.
PM me if you have an old Zenith carburetor laying around that you might want to sell reasonably.
goranvolvo
Posts: 17
Joined: Sat Jun 06, 2015 7:10 pm
Location: milwaukee Wi.

Re: Carb jetting

Post by goranvolvo »

where did you get the rebuild kit ?
krick3tt
Posts: 2457
Joined: Thu Mar 16, 2006 6:48 pm
Location: Denver, CO USA

Re: Carb jetting

Post by krick3tt »

I got my rebuild kit from SAV. Always good to go with the folks that supply us with parts, keeps them in business, helps us stay on the trail.
Any man who thinks he can be happy and prosperous by letting the government take care of him:
better take a closer look at the American Indian.---Henry Ford
goranvolvo
Posts: 17
Joined: Sat Jun 06, 2015 7:10 pm
Location: milwaukee Wi.

Re: Carb jetting

Post by goranvolvo »

did you get the ACCELERATOR PUMP seal in the kit ?
krick3tt
Posts: 2457
Joined: Thu Mar 16, 2006 6:48 pm
Location: Denver, CO USA

Re: Carb jetting

Post by krick3tt »

Fairly sure it was in there. It appears from the SAV site that they are out of stock...try EI, maybe Scott has two in his inventory. There were so many parts in the kit that I can't remember all of them, bet it is in there though.
Don't get the cheap one, the good one is about $170 each. still... better than a new carb, which may be impossible to get anyway.
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Any man who thinks he can be happy and prosperous by letting the government take care of him:
better take a closer look at the American Indian.---Henry Ford
pinzinator
Posts: 917
Joined: Thu Jul 29, 2004 3:12 pm
Location: Indio, California

Re: Carb jetting

Post by pinzinator »

The throttle bodies are also critical to proper carb operation and may need rebuilding, too. The round brass plates can wear and the throttle shaft/bore can wear, too, allowing air to get past and make synchronizing and smooth idling nearly impossible. If the shaft assembly has any play at all you need to check all clearances. SAV sells a slightly oversize throttle shaft, 8.3 mm vs the standard 8 mm version, in case the bore is worn. Be sure to replace the shaft seals and locking tabs, too. All of these potential tiny leaks can add up.
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Mr_Fixit
Posts: 12
Joined: Wed Jul 22, 2015 12:13 am
Location: Big wonderful Wyoming

Re: Carb jetting

Post by Mr_Fixit »

Well im about ready to change my main and idle jets in my K and was told by Dave at L.E. I would want to go from what he was sure was the 140 main to the 125. I purchased my pinz from Cali at sea level and plan to operate here at anywhere from 4 - 11,000 feet. I was lucky enough to get the jets from a salvaged pinz im planning on getting for parts that was setup for this altitude. Wasonly yold about the mains by Dave but my question is, shouldn't I change the idle jets, correction tubes and idle air jets also? Seems like after my trip the mountins (9 - 11,000 ft) the idle wont com back down all the way like it is when I first start it and it just gets warm.
Never argue with an idiot... They will only drag you down to their level then beat you with experience!

74 Pinz 710K
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