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Hpi trophy 4.6 exhaust pressure valve is blocked

Hpi trophy 4.6 exhaust pressure valve is blocked

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Old 11-07-2019, 12:43 PM
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Default Hpi trophy 4.6 exhaust pressure valve is blocked

Hello guys. I'm new to rc and bought my first car from someone. I'm having an issue with the fuel reaching the carb when trying to start. I cant prime it via putting a finger over exhaust exit while trying to start as this doesnt work. If I undo pipe and blow through the fuel starts moving through the pipes. I've had the exhaust off and cant blow or suck any air through the pressure valve. I've soaked it in old fuel and then in water still nothing. The cars only been used once the guy said he couldn't get the hang of tuning but I'm wondering if this is a problem from factory. Any ideas of how I can unblock it?
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Old 11-07-2019, 01:54 PM
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Are you opening the throttle up when priming? It will be much easier when you do rather than when it's closed ie at neutral throttle.
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Old 11-07-2019, 02:07 PM
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Originally Posted by Cainmurphy View Post
Hello guys. I'm new to rc and bought my first car from someone. I'm having an issue with the fuel reaching the carb when trying to start. I cant prime it via putting a finger over exhaust exit while trying to start as this doesnt work. If I undo pipe and blow through the fuel starts moving through the pipes. I've had the exhaust off and cant blow or suck any air through the pressure valve. I've soaked it in old fuel and then in water still nothing. The cars only been used once the guy said he couldn't get the hang of tuning but I'm wondering if this is a problem from factory. Any ideas of how I can unblock it?
There shouldn't be any restrictions on the tube that goes to the tank to the muffler ,the tank has to be pressurized from the muffler ,you need to fix that ,otherwise ,you will
never get the engine tuned right ,or you can also burn the engine up do to lean outs!

If the nipples are plugged ,you need to replace or clean them ,if the tube just simply goes into a hole in the muffler rather than on a nipple ,then pull it out an cut the end of the fuel
line in an angle so the tube doesn't bottom out inside the muffler ,also ,make sure that the tank lid seal is good ,if it leaks ,you will lose pressure there as well ,but ,make sure
that the tank is getting that pressure from the muffler!....

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Old 11-08-2019, 12:55 AM
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Should I be able to blow through the exhaust nipple freely? As I cant blow through it at all ?
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Old 11-08-2019, 10:34 AM
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Originally Posted by Cainmurphy View Post
Should I be able to blow through the exhaust nipple freely? As I cant blow through it at all ?
Yes ,you should be able to blow through it ,otherwise ,the nipple would not be there at all!
You need to punch what ever is plugging it out ,or if you cant ,remove the nipple or cut it off an run the tube down in the hole itself ,
make sure that the hole is slightly smaller than the tube for a snug fit!

I had blew an engine up one time while running when the muffler fell off the header as the tank loss the pressure ,so it is important that the tank is pressurized!
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