Help plz -Walbro 813 Carburetor

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Forist72

Forist72

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hey guys i got my Walbro WT-813 High-Performance Carburetor and Z-RC Tall Billet Intake Manifold today and installed it was running fine for a few min then lost power. Is there something i need to do special for this carb and anyone know if the setting are the same as is for the stock carb. Thanks for any help....
 
1 1/4 on the low and 1 1/2 on the high. does the bulb still have fuel in it? id you do anything to the fuel lines?
 
the 813 are really touchy to tune. the only thing i can think of is seal up the tiny hole that is on the right, backside of the carb as some dirt can get in their. it might be covered with the "Z" mainfold.(i plugged mine up awhile ago and forgot about it). start off with the stock settings and make tiny increment of about 1/16 of a turn. what problems are you having with it and have you narrowed it down to the carb? ie; air leaks and so on.. the main problem or tunning issue that i have had with every 813 is the transition from low to high speed. it seems like it stumbles right before the high carb jet kicks in. once you find that sweet spot you'll be golden. also arent you running the choke flap with that carb? ive never used them, but have seen one set-up and it just didnt look right to me. the 813 will start fine with no choke(suprisingly couse my 668 will never start without a choke). im sure the choke has nothing to do with your tuning issue, but if it was me; i would probly take it off till you get it right, but like i said, i highly doubt that "flipper" has anything to do with any tuning issue.
 
It will not start at all now. I cant get any fuel in the primer and checked the lines and toped it off with fuel. reset the settings as satt said. I also pluged the hole on the back side.hmmmmmm Im going to put the stock carb back on for now.
 
your not getting ANY fuel into the primer bulb? try hitting the clear bubble with your thumb. it wont work if you use your index fingure.. just kidding. don't throw your keyboard at me. im only joking..lol:D thats weird that nothing will get in their. try pulling the 4 screws off on the white plastic part that holds the bubbble on. thier is a very fine screen in their. its kind of like a diaphram. it should be bubbled around the sides and is very fragile there is a one way check valve kind of thing in there. if that screen/diaphram is clogged with dust or if the diaphram is wrinkled it wont allow fuel thru. that takes a long time to happen, but anything is possible i guess.
 
I put the stock carb back on and its doing the same thing. When i get to higher RPMs it starts cutting out. It might be the Z-RC Tall Billet Intake Manifold. I don't know I am puzzled .
 
sounds like you have to go back to the drawing boards. check for air leaks, cracks in the fuel line, your manifold gaskets. check to make sure the spark plug isnt fractured(that drove me crazy for about a week), check plug color for a lean condition(air leak). also the head/piston for scoring are plating flaking(loss in power/sluggish) tank ventulation(think you allready went over that). you can check for leaks really quick on the bench with wd-40. just spray it accros your base gaskits, intake and fuel lines at idle and listen for rpm spikes.
 
The 813 uses different settings than the other carbs:


I was using something like less than a turn on the low speed and about a turn and 1/16 on the high speed needle.


It cannot be mixing the fuel lines (unless the tank is full) because there is a point when the return fuel line wont be able to pick up fuel because it is set up shorter.


My guess is that your car is suffering from the fuel tank venting problem.


I have seen Redcats with this problem before and others that have not suffered from this. But not a big deal after all.


The only times I had a problem like that was with a cloged billet air filter (the car started fine but would not reach max rpms) and when the tank was pressurizing.
 
I just remembered the first time I used a 813 it ran awesome for ten minutes then it burned up the top end just like yours I put a new top and piston and it fired right up so I ran it real rich from then on
 
It might be orientation of your teflon gaskets on your Z-RC manifold. I got them on the Rampage and Baja. Double check them and make sure the fuel hole is lined up correctly with the carb and with the main body of the manifold. It's very easy to get those flipped around backward.
 
Thanks guys it was the fuel lines one was pinched a lil bit, and I think that the tank was not vented enough also as said above. Here is what i did to solve the problem so it will not happen again.
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its working fine now lotsO power :)
 
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