This site uses cookies to maintain login information on FarmallCub.Com. Click the X in the banner upper right corner to close this notice. For more information on our privacy policy, visit this link: Privacy Policy
NEW REGISTERED MEMBERS: Be sure to check your SPAM/JUNK folders for the activation email.
main jet removal
Forum rules
Notice: For sale and wanted posts are not allowed in this forum. Please use our free classifieds or one of our site sponsors for your tractor and parts needs.
Notice: For sale and wanted posts are not allowed in this forum. Please use our free classifieds or one of our site sponsors for your tractor and parts needs.
-
- 10+ Years
- Posts: 86
- Joined: Fri Dec 06, 2013 4:53 pm
- Zip Code: 00000
main jet removal
The main jet on our cub lo-boy broke off at the cross hole when I took the carb apart.The threaded carb body hole will not allow a tapered ez out in far enough nor a 1/4in hex shank torx bit. Any ideas? Feels tight [corroded] .That end is not threaded so a left cut drillbit would be no help
- Bus Driver
- 10+ Years
- Posts: 2917
- Joined: Sat Feb 11, 2006 5:26 pm
- Location: NC
Re: main jet removal
Is this an IH carburetor or a Zenith? Be cautious in removal attempts to avoid damage to the carburetor body.
Luck favors those who are prepared
-
- Team Cub
- Posts: 11851
- Joined: Tue May 25, 2004 8:02 pm
- Zip Code: 80501
- Tractors Owned: Cubs, MH Pony, Shaw, Allis G, 1934 Silver King, JD LA and LI, Gibson D, David Bradley Tri-Trac
- Circle of Safety: Y
- Location: CO, Longmont
Re: main jet removal
This is the exploded view of the Zenith. Are you talking about part # 20, part # 33, or is it an IH carb?
Bob
"We don't need to think more,
we need to think differently."
-Albert Einstein
we need to think differently."
-Albert Einstein
-
- Team Cub
- Posts: 11851
- Joined: Tue May 25, 2004 8:02 pm
- Zip Code: 80501
- Tractors Owned: Cubs, MH Pony, Shaw, Allis G, 1934 Silver King, JD LA and LI, Gibson D, David Bradley Tri-Trac
- Circle of Safety: Y
- Location: CO, Longmont
Re: main jet removal
Here's the IH carb, main jet is part# 28.
Bob
"We don't need to think more,
we need to think differently."
-Albert Einstein
we need to think differently."
-Albert Einstein
-
- 10+ Years
- Posts: 86
- Joined: Fri Dec 06, 2013 4:53 pm
- Zip Code: 00000
Re: main jet removal
It is an IH carburetor. very carefull drilling or replace the carb I'm thinking
-
- Team Cub Mentor
- Posts: 4127
- Joined: Tue Jan 11, 2005 12:12 pm
- Zip Code: 13830
- eBay ID: adak8965
- Circle of Safety: Y
- Location: Oxford, NY
Re: main jet removal
Carefully drill out the old jet with a left handed bit. If you mess it up I can helicoil it for you.
-
- Team Cub
- Posts: 11851
- Joined: Tue May 25, 2004 8:02 pm
- Zip Code: 80501
- Tractors Owned: Cubs, MH Pony, Shaw, Allis G, 1934 Silver King, JD LA and LI, Gibson D, David Bradley Tri-Trac
- Circle of Safety: Y
- Location: CO, Longmont
Re: main jet removal
In an IH carb, the main jet is threaded at the end opposite the hex head. You can carefully drill out the broken piece. I'd suggest spraying it with Kroil or a similar penetrant for several days. You can spray it through the idle tube hole and the idle adjustment screw hole as well as from the inside of the float bowl. I don't remember offhand what the threading is. If the threads get boogered up, they can be helicoiled, but that gets more involved as you have to enlarge the hole is the casting to get the STI tap in there. If you're not confortable doing it yourself, you can send it to one of the carb guys to have it done. Your initial description still does not sound like the main jet to me, but It may just be the way you are describing the threading.
Bob
Bob
"We don't need to think more,
we need to think differently."
-Albert Einstein
we need to think differently."
-Albert Einstein
-
- 10+ Years
- Posts: 86
- Joined: Fri Dec 06, 2013 4:53 pm
- Zip Code: 00000
Re: main jet removal
The plot thickens. It is an IH carb #3645?9-R9.The ?could be a 3 or 5.The main jet is #28 in the pic but the jet is stepped up on the hex end and threaded to the outer bowl shell.I will take pictures later.I think this engine was a power unit.I will check the numbers later.This moter had a wider speed range than our other cubs .idel right down and rev up high
-
- 10+ Years
- Posts: 86
- Joined: Fri Dec 06, 2013 4:53 pm
- Zip Code: 00000
Re: main jet removal
Here is a picture from the bottom up.main jet from a difernt cub.the broken main jet and the carb. the engine casring code is X so 1952 .Not original to a lo-boy.Would power units have different jets for more power or speed?
- Attachments
-
- barn 683 (Medium).jpg (42.73 KiB) Viewed 1095 times
-
- Team Cub Mentor
- Posts: 4127
- Joined: Tue Jan 11, 2005 12:12 pm
- Zip Code: 13830
- eBay ID: adak8965
- Circle of Safety: Y
- Location: Oxford, NY
Re: main jet removal
So the jet you took out is definitely no what should be there. If you remove the broken part a new jet should screw in with no problem. The shoulder on the new jet will be large enough to seal.
-
- Team Cub
- Posts: 11851
- Joined: Tue May 25, 2004 8:02 pm
- Zip Code: 80501
- Tractors Owned: Cubs, MH Pony, Shaw, Allis G, 1934 Silver King, JD LA and LI, Gibson D, David Bradley Tri-Trac
- Circle of Safety: Y
- Location: CO, Longmont
Re: main jet removal
The main jets all look the same, but have a different size hole on the end depending on the tractor and application.
Bob
Bob
"We don't need to think more,
we need to think differently."
-Albert Einstein
we need to think differently."
-Albert Einstein
-
- 10+ Years
- Posts: 86
- Joined: Fri Dec 06, 2013 4:53 pm
- Zip Code: 00000
Re: main jet removal
I don't think a new jet will seal as the hole is larger than the carb I took the regular jet from. The threaded hole on the carb is 3/16 in. Normal is likly 1/4in.I don't think the brake is fresh But it ran quite well except it was very fussy about the choke until warmed good .I never tryed a tack on it but I'm thinking 2500 rpm.[If it ain't broke don't fix it] but I thought I could improve the starting for grandkids..So is this a special carb and jet or did someone modify it? It shure had more power than our other cubs
- Don McCombs
- Team Cub Mentor
- Posts: 17477
- Joined: Mon Feb 03, 2003 6:45 am
- Zip Code: 21550
- Tractors Owned: "1950 Something" Farmall Cub
1957 Farmall Cub w/FH
1977 International Cub w/FH
1978 International Cub
1948 Farmall Super A - Circle of Safety: Y
- Location: MD, Deep Creek Lake
Re: main jet removal
It's been modified.
-
- Team Cub Mentor
- Posts: 5634
- Joined: Thu Aug 03, 2006 6:20 am
- Zip Code: 43358
- Tractors Owned: 48 Cub Diesel (Cubota)
53 Cockshutt 20 restored (Shooter)
52 Cockshutt 20 unrestored
47 Leader "B" (Herckie)
49 Leader "D" (Princess)
49 Leader "D" very rough
48 Leader "D" unrestored
Kubota B6200E
Kubota B6200HST
Kubota B8200HST-D - Circle of Safety: Y
- Location: OH West Mansfield
Re: main jet removal
That was just a work around after someone got too rough with the main jet and twisted it off by over-tightening it. They just rigged a plug to seal the opening. The broken jet still functions the same as it did before it was broken. If you're concerned that the the replacement jet will not seal, the best alternative may be to leave it as it is.
- Bus Driver
- 10+ Years
- Posts: 2917
- Joined: Sat Feb 11, 2006 5:26 pm
- Location: NC
Who is online
Users browsing this forum: No registered users and 46 guests