compression question
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compression question
First off, I have searched. I have been trying to start a rebuilt 12a for a few days now. Today I checked the compression, I am at about 50 on both rotors. This was obviously on a cold motor, is this too low? The motor was just town down and all seals are good. I know the compression should be a lot higher but I am guessing that is on a motor that has been running? Do I need to start over? I have read about dumping atf and oil down the plug holes but have not tried yet. I guess I don't want to try if it's not worth it.
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#4
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I presume it is a 12a carby motor , just tip an oil cap full of oil down each primary throat of carby this will boost up compression and engine should start , once it has run for a while seals will bed in a little and should start easier
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i wouldn't expect an engine that hasn't run to have high compression, especially if its flooded/other. it should be even though.
once its started and running ok, then compression should be better
once its started and running ok, then compression should be better
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It is a proud day in my world. I finally got my 12a running. It was only for a short time but it was running. This is my first 7, I tore the motor down, ported and rebuild, twice (first time I didn't have the rotors in correctly). I still have much to do but it's a proud day in my world.
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I did spend a fair amount of time but I am having a problem with my fuel supply. I don't think my pump is putting out enough psi. I have a new one on order but for a while I wasn't getting any gas in the carb at all. I am also new to webber/dells so this will be a learning expierence as well.
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I have a 48 dell with a red holley and regulator. I'm not sure if my carb is plugged or I am not getting enough pressure. The problem I am having is I am not getting fuel. When I open the throttle the accelerator pump should shoot fuel into the barrel, correct? It doesnt, not all of the time. The carb isn't new but it is clean. I don't know if there is some contaminants in the carb or if the pump isn't putting out enough fuel. The floats are full but the pump sounds like it's running on half power and I don't see a lot of fuel running through the filter.
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That's how I knew something was wrong. I used to be annoyingly loud and now it's not. I think it has something to do with the magnets on top of the motor. Not sure what they are called but they were a little worn out when I looked a year ago. I was going to tear it down again but if my memory is correct those parts are half as much as a new pump. I did get my new pump in the mail yesterday, I hope being cheap doesn't screw me again. I got a knock off holley off summit.
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lol, my friend had a bridgeported Rx3, that did 230rwhp and you could clearly hear the holley fuel pump over the engine.... that is a LOUD pump
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I can get it to start easily when I add oil to boost pressure but it will only stay running for a short period, 20 seconds and I've only ran the motor a few times. When you say "once it has run for a while" how long are you talking.
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Just a update. I have the car running without any oil at all now and very happy about that. It is insane how much smoke burning oil creates. I'm surprised I didn't have the fire department at my house over the last couple days. Thanks for all the help guys.
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