Question abut the carb????

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rcspeedmart

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I am going to rebuild my top end on the motor OBR suggest the 813 carb for the race ported rebuild. On the 813 carb there is no choke so want that make a bear to crank?


http://shopping.netsuite.com/s.nl/c.885035/n.1/it.A/id.4147/.f


the 813 carb is the only one that states: Features 2 tunable jets and larger venturi for more fuel / air flow. Increases low end acceleration.


I know from reading the forums there are many different opinions on carbs I an just super confused right now so any and all help and opinions will be greatly appreciated. Thanks.
 
Oh ok I live in GA so where does where you live have to do with needing a choke or not? Is it the climate? So what would be the procedure to crank without a choke? Press the bulb until it fills with fuel and hope that you don't flood the engine? So is there a carb like the 813 that's with a choke or will I just have to have the lag in the low end acceleration and have the choke?
 
If your engine is cold, then you typically need a choke to start it. On a cold day, you can heat it up with a hairdryer to loosen it up and it will start with no problems. I prefer to have my carbs custom built for big motors and have him add a choke.
 
Go with the 990. It's the same, but it doesn't have the accelerator pump. 813's have a habit of eating throttle shafts. Starting without a choke isn't all that bad, just takes a few extra pulls.
 
Deluge said:
Go with the 990. It's the same, but it doesn't have the accelerator pump. 813's have a habit of eating throttle shafts. Starting without a choke isn't all that bad, just takes a few extra pulls.
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Ok thanks for all the info so I found the 990 which states "The WT-990 Carburetor is the same as the WT-813 WITHOUT an internal acceleration pump." but it still says "tend to experience a lag in low-end acceleration when tuned for peak power." so I am guess it will do the work without the acceleration pump?

So to crank you would do as usual prime the bulb untill it fills with gas and pull the cord a few more extra times?

Thanks guys for all the help.

http://shopping.netsuite.com/s.nl/c.885035/n.1/it.A/id.7550/.f
 
rcgasser said:
Ok thanks for all the info so I found the 990 which states "The WT-990 Carburetor is the same as the WT-813 WITHOUT an internal acceleration pump." but it still says "tend to experience a lag in low-end acceleration when tuned for peak power." so I am guess it will do the work without the acceleration pump?So to crank you would do as usual prime the bulb untill it fills with gas and pull the cord a few more extra times?

Thanks guys for all the help.

http://shopping.netsuite.com/s.nl/c.885035/n.1/it.A/id.7550/.f
Click to expand...
DDM said:
Engines with the standard carburetor (WT-603, WT-668, etc) tend to experience a lag in low-end acceleration when tuned for peak power.
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The 603 and the 668 experience the lag. The 990 will do the job.

And yes, all it takes is 2-3 extra tugs.

Also, the stock needle settings for the 990 are:

H needle : 1 1/4

L needle : 1 1/4
 
Ok cool thanks for all of your help!!!!!! From watching all of the rebuild the top end videos on you tube I have decided to try to rebuild a top end and hope it works. I want to put on the new carb then since I will have to break in the engine again. So thanks fr all the help!!!!!!!!!!!!
 
Ok lol thanks I am really nervous about doing it I am not engine mechanical incline at all so I will be going very slow and keeping my finger crossed. Thanks once again.
 
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