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Author Topic:   Carb Question
Alltel
Dirt Maniac

Total posts: 180
posted August 14, 2005 06:01 PM  
Where can I order a rebuild kit for a 4150 on alcohol? Every kit I find is for gas.

The carburetor will not stop running fuel into the motor after it shuts off. I'm thinking the nytrophil floats are filling up. Can you run brass on Alky without crushing them? What else may be my problem?

KPLugnut
Dirt Forum Champ
Total posts: 1019
posted August 14, 2005 07:05 PM  
Sinking floats will not be a cause for the bowls draining into the engine after it is shut off other than if the float level is REALLY too high and then only the excess will drain, but the motor will run like garbage anyway. The most common cause is leaking power valve(s). Brass floats or plastic (occasionally) are what most builders use in methanol carbs. Nitrophyl floats don't usually have a direct problem with alky unless they are "cut" oval track style, and the epoxy or sealer used isn't compatible with alky. That's the most common cause of failure with those (also why we don't use 'em in alky carbs anymore. LOL).
Nitrophyl will work fine unless they're really old or have "dents", marks or scratches in them. Then they act like a dish sponge...

We can supply basic and master rebuild kits for any carb, gas or alky, street or racing. The master kits include all new hardware, skrews, bolts, etc.
Feel free to contact us.

Kinetic Performance http://www.kineticperformance.net

[This message has been edited by KPLugnut (edited August 14, 2005).]

Alltel
Dirt Maniac

Total posts: 180
posted August 15, 2005 08:46 AM  
Thanks KP

The fuel is leaking from the boosters when the motor is shut off. I am using the cut nitrophyl floats. The ones I'm currently running have what looks like a ball bearing glued into the top of it but the glue has come off. The power valves appear to be good. I'm going to replace the floats with brass and the needle and seats just to see if it works because I have them. Then I will go and buy some power valves. The motor has been running like absolute garbage. It feels like its down about 200 horses, is sluggish, and won't turn within 1000 RPMs of what it used to.

Could you give me general price for an alky rebuild kit? How about a new carb?

[This message has been edited by Alltel (edited August 15, 2005).]

KPLugnut
Dirt Forum Champ
Total posts: 1019
posted August 15, 2005 09:29 AM  
Sent ya a PM...

Modified 57
Dirt Roller

Total posts: 8
posted August 15, 2005 01:49 PM  
Are you running fuel bypass on the back of a fuel log with a fuel pressure regulator and a fuel gauge . The steel alcohol needeling seat .150 or larger, can not hold more than about 6 lbs pressure at idle. And it well flood out of the boosters and vents. Pressure well come up when you give it the gas. (MOD 57 on Alcohol)

J3
Dirt Maniac

Total posts: 188
posted August 15, 2005 02:57 PM  
KP, I run a 86 LTD pure stock. Have to run stock 2bbl carb. I am running a 1.23 carb now. The carb is completely stock except for changing jets. I don't quite understand the power valve and was hoping you can help me.

1st What size power valve does it have?
2nd What size power valve should I have?
3dr What exactly does a power valve block do?
4th Would I be better off runnin a block?

If you need any other info about motor to be able to answer these questions, just let me know and I will try to get ya that info. Thanks for you help.
Johnny

Alltel
Dirt Maniac

Total posts: 180
posted August 15, 2005 06:38 PM  
The needle and seat and floats fixed the flooding, but I have been having trouble with the front accelerator pump. It works a little(it's a weak and slow spray) when the motor is off and none at all when it is running, but the car doesn't stumble when you hit the gas. It does work when it is running if you slam it down real fast but not at all if roll into it. The secondary works fine. The front is a 50 and back is a 30. I've tried two different pumps and check valves. Maybe I have two bad pumps? Anything else that could cause this?

I appreciate the help KP.

[This message has been edited by Alltel (edited August 15, 2005).]

KPLugnut
Dirt Forum Champ
Total posts: 1019
posted August 15, 2005 08:11 PM  
partially clogged and restricted pump circuit, probably in the check needle area. Also check that the orifices in the squirters are clear of fuel deposits.
Sorry, I missed this thread and haven't had time to get back here 'till now.

KP

Alltel
Dirt Maniac

Total posts: 180
posted August 16, 2005 04:49 PM  
Just FYI, I figured out the problem with the accelerator pump. The seal was messed up between the metering block and the throttle body. I put in a makeshift gasket between them and now it squirts like a fire hose.

With changing the needle and seats, the floats, and now this, it sounds like a completely different motor. I sure hope it runs like it.

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