I have a hyper .21 8 port race engine and when I start the car it idles fine but when I sit the car down and drive it out about 15 feet and back the engine is revved really high and my temps are close to 300f. I have taken the engine aart to seal the carb, backplate and HSN housing with RTV sealant but dont know what else it could be. I have just recently ordered a new fuel tank and new tubing to replace, can someone advise any other possible causes.

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if its made like the hyper 9, then its got some flaws!











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Sounds really lean.... Check and see what your owner's manual say about the basic needle settings. Start from there. Adjust your high speed needle first making long straight away passes. I prefer to run my engines a bit rich. After that, fine tune your low speed needle. I usually just start by letting my car idle for about 15 seconds and then gunning it. If it sounds like its starving out, I open the lower speed needle a bit. If it babbles (which is most likely the case from the factory settings), like it's rich, I lean it out a bit.

As you get your setting correct, you'll eventually have to set your idle speed. Engines tend to idle faster when the low speed needle is set too lean. As you richen it up (the process above), expect the engine to stall when it's idling. You'll most likely have to turn the idle screw in.

PS.

It also could be a piece of dirt caught in your carburetor. I check that by backing out the high speed needle an opening the carb (which pull the low speed needle out of the way) and shooting some fuel through the carb fuel inlet. Another problem could be that the pressure line is melted and not pressurizing the fuel tank. Check all your fuel lines.

Good luck.