Off-Road Forums offers a place for off road
enthusiasts to chat about everything from ATVs, jeeps, 4x4 trucks and
dirtbikes, to racing, snowmobiles or just general off road stuff.
Sponsored Links | | Jeep-Short Wheelbase All discussion of short wheelbase Jeeps: CJ, TJ, YJ | 
10-05-2009, 08:07 PM
|  | Apprentice | | Join Date: May 2007
Posts: 54
| |  mc2100 fuel return line
I was just browsing the net and found some things about a fuel return line on the mc2100. Where is it located? I don't have one on my setup. I've only got PCV, vac. advance and fuel line/filter.
Is that ok? It does start rich after it's been running for a while...
|
10-05-2009, 09:01 PM
|  | Moderator | | Join Date: Nov 1999 Location: Troy, Ohio
Posts: 7,288
| |
Can't say they never had one, but Ive never seen it on a 2100. And never have done one on a jeep conversion I've done.
If they did I'd like to know years and application as I've missed it. To the best of my knowledge I've only seen a few times a carbed engine had a return line. (and most were jeeps) So I'm open to references.
|
10-06-2009, 07:02 AM
|  | Addict | | Join Date: Jun 2003 Location: Valdosta, Georgia
Posts: 400
| |
This is based on threads I have read in the past.
I think the fuel return line and the 2100 has more to do with keeping the stock filter with the return line or not when running a 2100/2150.
Some remove the stock filter when running a 2100 with no problems - others experience a rich/flooding issue.
The stock fuel pump can be too much for these carbs and an electric fuel pump or fuel regulator is used to compensate.
Don't want to get into the "which is better" debate. Again, past threads I've read.
I have always used the stock filter with return with these carbs.
__________________
No matter where you go, there you are.
|
10-07-2009, 10:34 AM
|  | Official Historian | | Join Date: Sep 1999 Location: Conway, AR
Posts: 8,008
| |
Quote:
Originally Posted by Tim-E  I was just browsing the net and found some things about a fuel return line on the mc2100. Where is it located? I don't have one on my setup. I've only got PCV, vac. advance and fuel line/filter.
Is that ok? It does start rich after it's been running for a while... | Just to clarify. The return line isn't located on the carb. The fuel line from the pump to the carb has a filter with two outlets... one to the carb and one for return.
__________________
"As the circle of my knowledge grows, so grows the circumference of the unknown." - Isaak Newton
|
10-07-2009, 03:17 PM
|  | Mud in my Veins | | Join Date: Apr 2000 Location: Winston-Salem, NC
Posts: 5,357
| |
Quote:
Originally Posted by WILL Just to clarify. The return line isn't located on the carb. The fuel line from the pump to the carb has a filter with two outlets... one to the carb and one for return. |
^^FACT!^^
OTOH, my rig didn't have a return line at all and ran good (as good as a carb will run) for the past 8-9 years. No issues with the needle getting blown off the street, flooding (caused by excess pressure, stoopid angles were another issue  ), or vapor lock (from lack of flow/circulation)...
I ended up using the OEM supply line as a return for the TBI...
|
10-07-2009, 03:41 PM
|  | Moderator | | Join Date: Dec 2001 Location: Belleville, Illinois
Posts: 9,617
| |
Years ago I was taught that the reason for the return line is prevention of vapor lock - gasoline boiling in the engine-mounted pump from under-hood heat. With electric pumps it allows the fuel flow to serve as a coolant for the pump. It should have only a slight affect on the fuel pressure at the carb, and is not meant as a pressure reduction device.
__________________
EVERYTHING's easy for the guy who doesn't have to do it. B. Dash Fabrication | | Thread Tools | | | | Display Modes |  Linear Mode | 
Posting Rules
| You may not post new threads You may not post replies You may not post attachments You may not edit your posts
HTML code is Off
| | |  Off-Road Videos -
Check out over ten years of extreme 4x4 action, product testing and the Off Road Nation at play. Baja racing to rock crawling, ATVs in the sand to motorcycles in the dirt, it's all here. Rate them, share them and upload your own.
|  ATV Reviews -
Honda, Suzuki, Yamaha, Polaris, Kawasaki, Can-Am. First rides to long-term tests, check out the latest in ATVs, UTVs and Side-by-Side vehicles of every make and model. Read expert opinions and follow custom project vehicles. |  Axxxtion Sports.....
Axxxtion Sports is heating things up with their 2010 Winter Heat snowmobile calendar! Simply Sexy! | All times are GMT -5. The time now is 08:22 AM. |
