CARB/FUEL PUMP QUESTION

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Lwells
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CARB/FUEL PUMP QUESTION

Post by Lwells »

I have an 0-320 that Smitt Aviation just rebuilt the carb on so it should be right. My problem is that when I turn the fuel pump on for about 3 seconds or so it starts running fuel out the air cleaner mounting bracket. Airplanes are gravity feed so I know they don't need a pump but I figured that since an airboat fuel tank is on the floor then it would need a fuel pump to run but this one will run fine with the fuel pump off after I turn it on for a couple seconds and then back off and start it. Or I should say it runs fine at the house but I haven't tried it on the water yet for I just got the boat ready to try but I wanted to find out about this fuel deal before going out. If I start it with the fuel pump on then it starts but floods. If it does have to have a pump then I may have too much pressure and may need to put a regulator on it but I don't know so help me if you can.

Lwells
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Re: CARB/FUEL PUMP QUESTION

Post by Lwells »

I'm not sure for it came with the boat and the boat had an 0-360. It has three studs in the top of it that mount in rubber and it looks like a small fuel filter and the wires plug into the bottom of it. I don't know whether that tells you anything or not but until I look at it tomarrow that is all I can tell you. I have some auto fuel pumps like I used on experimental Helicopter rotax engines but I didn't change to one of them for I figured if it worked on the 360 it would work on mine.

Gary S
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Re: CARB/FUEL PUMP QUESTION

Post by Gary S »

Call Smitt and ask him. Sounds like a carter pump.

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JT540
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Re: CARB/FUEL PUMP QUESTION

Post by JT540 »

check your line pressure if its more the 6 lbs its too much 4 to 5 is what the need but they will hold 6 if that is ok then you have either a bad needle and seat or a stuck float that's not letting it shut off fuel when the bowl fills
"THE MORE I LEARN ABOUT WOMEN THE MORE I LOVE MY AIRBOAT"

schmidtav2
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Re: CARB/FUEL PUMP QUESTION

Post by schmidtav2 »

It sounds as if you have a Carter pump, we use the Facet pumps, Facet makes several different pumps, IE: different pressures, size of fittings, free flowing, not free flowing, etc. If the carb holds fuel pressure with the engine running at idle with only the manual pump working, then the carb should be ok and you have a electric fuel pump pressure issue, if you still run fuel out of the carb with it running at idle, then you have a carb issue, (float issue or needle and seat issue). If you need a good Facet pump at a decent price we have them in our store, Schmidt Airboats 954-782-2845

Lwells
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Re: CARB/FUEL PUMP QUESTION

Post by Lwells »

To my knowledge the engine doesn't have a pump for I am hooked direct to the Carb. This engine belonged to a guy whom owned a marina repair business in ft. Lauderdale(i'm saying this due to seeing Schmitt on here) I waited for them to check, test, and repair anything it needed about a month ago. Just saying this due to they know this guy very well and probably will remember the engine for it is 180 or 185hp. The engine runs ok without a pump but I'm sure that it will need the fuel pumped up to it if I run it above idle or just hitting the throttle for a second. I'm either going to put a regulator on it or use one of my small inline pumps that I have. I appreciate all the good help and hope to get to know you guys soon. You have been a big help.

Lwells
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Joined: Sat Nov 15, 2014 9:18 pm
Location: okeechobee

Re: CARB/FUEL PUMP QUESTION

Post by Lwells »

Well, I tested the pump pressure and it was 38lbs. No wonder Carb couldn't handle it. I bought a fuel regulator but couldn't use it with this pump for it can't stand over 15lbs so I'm taking pump off in the morning and putting one of my other pumps on with it for I know they are around 4to 6lbs so I will be able to reduce to 3. I have been misspelling Schmidt's but hope they understand I'm more redneck than college graduate.lol. Thanks for the help .

Lwells
Southern Airboat Member
Posts: 327
Joined: Sat Nov 15, 2014 9:18 pm
Location: okeechobee

Re: CARB/FUEL PUMP QUESTION

Post by Lwells »

Well, changing pump worked and all is well. Thanks for info

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