FG Monstertruck - Engine Problems!

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My two new Iridium sparkplugs arrived today. No luck with that though. Same crap. A bit easier to start, but wont help me much :P

Anyways i figured that it has to be the carburetor that's f:ed up. So i did a complete disassemble of it again. And googled around a bit and wound up in a chainsaw forum or something were they mentioned service etc on these Walbro carbs. Also a dude that had problem with reaching high RPMs due to a worn out diaphragm. I had reflected over it before when i disassembled the carb but didn't think much of it, but now when looking at the repair kits for the carb and the assembly metering diaphragm on those there is kind of an uprising in the rubber part around the metal disc with holes in it. On mine its totally flat. Apparently these diaphragms shrink over time and has to be replaced. Otherwise the engine wont get enough fuel when you open the throttle apparently.

Number #34 in this PDF (in the assembly plan)
http://www.mvvs.nl/Manuals/WTmanual.pdf

Should look like this i suppose, notice the uprising part in the membrane around the metal disc.
http://www.rc-car-online-shop.de/cosmoshop/pix/a/n/fg_7370-1163766306.jpg

I tried to take a picture on mine with my Iphone camera (wich is worthless) since my digital camera is at work. It's attached in this message, kinda hard to see but its flat and somewhat deformed.
So i will try to get a hold on a repair kit for the carb and see if that helps. I will probably get the new carb before that but like sperera said earlier it would be nice to have a spare carb.
 

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Well time for a little update. I sat and read through a Walbro PDF explaining how their carbs works. The carb was lying disassembled on my desk with the metering diaphragm loose on it and it hit me. When i brought it to my apartment from my fathers house where it had been standing for two years i decided to bring it all down to clean it up. Thats when it must have happen, i did disassemble the carb then and cleaned it out. And behold... i mounted the metering diaphragm upside down... jeez, i am such a f'ing idiot. When i disassembled it after that i figured that was the way it was supposed to be. The PDF explained that the needle arm has to be flat so it will move the metering diaphragm the right way. I looked at the diaphragm and noticed the little pin on the metal disc. Then it hit me, the arm is supposed to touch that pin and move it up and down. I thought for myself "can i really be this stupid?!"
So i turned it the other way and assembled it again. And the engine runs perfectly now on the high end.
So now i am gonna sit my ass down in the corner and feel ashamed. Thanks for the replys and sorry for wasting your time!

BASHING TIME!
 
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MrFnisse said:
Well time for a little update. I sat and read through a Walbro PDF explaining how their carbs works. The carb was lying disassembled on my desk with the metering diaphragm loose on it and it hit me. When i brought it to my apartment from my fathers house where it had been standing for two years i decided to bring it all down to clean it up. Thats when it must have happen, i did disassemble the carb then and cleaned it out. And behold... i mounted the metering diaphragm upside down... jeez, i am such a f'ing idiot. When i disassembled it after that i figured that was the way it was supposed to be. The PDF explained that the needle arm has to be flat so it will move the metering diaphragm the right way. I looked at the diaphragm and noticed the little pin on the metal disc. Then it hit me, the arm is supposed to touch that pin and move it up and down. I thought for myself "can i really be this stupid?!"
So i turned it the other way and assembled it again. And the engine runs perfectly now on the high end.
So now i am gonna sit my ass down in the corner and feel ashamed. Thanks for the replys and sorry for wasting your time!

BASHING TIME!
Click to expand...

Sorry bud I laughed at this especially where you call yourself an f'in idiot :lol::lol: Ive done stupid stuff but thought it was just me & that is exactly what I say to myself :lol::lol: Glad you got it sorted in the end :D
 
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My Walbro HP-813HP came today so i installed it, took it down to the parking place next to my apartment for a fast test run. First time i run it properly with the Tuning Pipe. And i was totally amazed. It runs perfect now, and what power. Insane acceleration, can do some great wheelies with it now :D
Gonna take it out with my girlfriend to a better drivingplace tomorrow hopefully. Will see if i can manage to take some pics or a video!
 
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