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Old 06-01-2014, 06:33 PM   #20
Jeff in BC
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Join Date: May 2010
Location: Richmond BC
Posts: 56
Default Re: Marvel Carburetor Disection

Hi All

This is part 3 of the carburetor dissection and is quite a long post. Actually too long, I’ve had to split this post in two (too many pictures).

The Idle System

When we left off last time we had fuel to the main jet and bowl drain plug so we will continue from there.



Photo 1 – Idle system with components identified:
10 – Idle Fuel Passage
11 – Idle Jet
13 – Idle Adjusting Needle



Photo 2 – Fuel entry to main jet, this is where we left off.

Now I will remove the Main Nozzle. The main jet, as shown above, is part of the main nozzle. Removal of the nozzle may be difficult and I would suggest using some of the following hints.

1 Make sure you use a good fitting screwdriver even if you have to grind one to fit. You can see the damage in the photo from using a poorly fitting screwdriver.

2 Clean the threads the best you can before attempting removal.

3 Soak the nozzle down with penetrating oil and let it sit then clean it out with carb cleaner. This should remove a lot of the junk. Now soak down one time with the penetrating oil and leave it there during removal.

4 The nozzle is a fairly tight fit in the carb body so be patient removing it, you may need to rotate it back and forth add more penetrating oil.

5 If the above doesn’t work or the slot is damaged you may need to carefully use an impact driver. I did.



Photo 3 – Main nozzle and seal.

The seal may be left behind in the passage where the nozzle was removed; it could be very hard to see.

Now back to the idle fuel path.



Photo 4 – Nozzle showing idle fuel path (green wire).

The red line represents the fuel level in the fuel bowl.



Photo 5 – Looking into fuel drain plug hole to show idle fuel passage (10).



Photo 6 – Side view of lower portion showing fuel path (green wire) from the drain plug to the idle jet (11).



Photo 7 – Side view showing idle well (10) entering the upper portion of the carb.

Notice the protrusion on the exterior just below the idle adjusting needle; this is for the idle tube.

The rest of the idle system is contained within the upper portion of the carb. I’ll break the post here and continue with the upper portion separately.

Jeff
Attached Images
File Type: jpg Idle01.jpg (46.8 KB, 2949 views)
File Type: jpg Idle02.jpg (46.8 KB, 2919 views)
File Type: jpg Idle03.jpg (85.4 KB, 2939 views)
File Type: jpg Idle04.jpg (74.5 KB, 2933 views)
File Type: jpg Idle05.jpg (39.7 KB, 2938 views)
File Type: jpg Idle06.jpg (40.6 KB, 2927 views)
File Type: jpg Idle07.jpg (52.0 KB, 2919 views)
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