450 FCR with pulse pump return line issue

H

Hooper07

Member
How are people setting up there fuel return line for a Honda 450 w/ FCR carb. The pulse pump is too strong for the float. I am looking at restricting the return line to keep correct pressure at the carb. With my return unrestricted it is doesn’t get any fuel at the carb inlet. I am looking at using some sort of pill system like a sprint car so I can test and adjust the return. Clone jets or something of that style.

What has been proven to work so I’m not spending in needed time setting this up correctly.

Any help is appreciated.
 
use the Mikuni round pulse pump with two outlets. One to the carb and the other back to the tank with a restrictor pill in it. I used 1/4" aluminum round bar and drilled a 1/8" hole in it. The pulse of intake.
 
At first I ran a simple tank cut off valve and adjusted it to where it seemed to work best. That's how the KTM in my profile pic was setup. I've since learned that the FCR can have a different taper seat and needle installed to address the fuel pump issue. Most knowledgeable FCR builders can address this for you. (As in tell you which parts you need if they want to.) The normal round single outlet pulse pump flows more than enough fuel to feed an FCR. If you need more assistance, I can get you the name of a builder here in TN that is highly recommended on FCR carbs. I don't have his number right off the top of my head but I can get it.
 
flattop1 said:
use the Mikuni round pulse pump with two outlets. One to the carb and the other back to the tank with a restrictor pill in it. I used 1/4" aluminum round bar and drilled a 1/8" hole in it. The pulse of intake.
Click to expand...
That is very similar to what I was thinking of doing. I have a single outlet standard Wakbto pump that a clone would run. I have a tee fitting on the outlet line going back to tank. Was thinking of adding a pipe with threaded pills/clone jets that are sized in .010 differences. Clone jets are cheap and straight thread.
 
ABR #69 said:
At first I ran a simple tank cut off valve and adjusted it to where it seemed to work best. That's how the KTM in my profile pic was setup. I've since learned that the FCR can have a different taper seat and needle installed to address the fuel pump issue. Most knowledgeable FCR builders can address this for you. (As in tell you which parts you need if they want to.) The normal round single outlet pulse pump flows more than enough fuel to feed an FCR. If you need more assistance, I can get you the name of a builder here in TN that is highly recommended on FCR carbs. I don't have his number right off the top of my head but I can get it.
Click to expand...
I've got the same issue on my wing kart with a CRF450 on it. If you could provide the name of the carb builder that would be great.
 
Jet-Lab Carbs
+1 615-420-4400
I can't remember the name of the guy I spoke with. Just ask about the needle and seat for the FCR while running a fuel pump. Most single outlet pumps are in the 15l/h range, and I can't remember the max Psi.
 
ABR #69 said:
Jet-Lab Carbs
+1 615-420-4400
I can't remember the name of the guy I spoke with. Just ask about the needle and seat for the FCR while running a fuel pump. Most single outlet pumps are in the 15l/h range, and I can't remember the max Psi.
Click to expand...
Thank you sir
 
Hooper07 said:
How are people setting up there fuel return line for a Honda 450 w/ FCR carb. The pulse pump is too strong for the float. I am looking at restricting the return line to keep correct pressure at the carb. With my return unrestricted it is doesn’t get any fuel at the carb inlet. I am looking at using some sort of pill system like a sprint car so I can test and adjust the return. Clone jets or something of that style.

What has been proven to work so I’m not spending in needed time setting this up correctly.

Any help is appreciated.
Click to expand...
If want save mental melt down . Use 2 fuel control valves , one feed all way open. Return line with the second control valve to meter fuel pressure back to tank . This set up can be adjusted to you specific needs and fuel pump .
 

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