Walbro WT-668 Carb overview and install. Water cooled sport's new carb.

[@Fotopro]

Thanks for the reply. I’ll keep an eye out for the video.

[@kaiyuVFX]

Just found your channel last week been binge watching while wrenching on my bigfoot 🔥

[@aaronpratt89]

Hell yea man! I’m trying to get better at editing lol Thanks for the support!

[@josephagetti8122]

took me a good couple hours i thought the spring that came with the hp carb was too stiff.. anyway, good ! thanks for everything.

[@chadr00]

Cut the metering spring is something I hadn't heard of. I bent the metal piece holding the needle so that it opened sooner. It helped to add more fuel but it wasn't easy to tune accurately. It was often too rich on low and mid throttle. Does cutting the spring shorter have the same negative effects?

[@aaronpratt89]

@@chadr00 raising the fulcrum doesn’t change the pop off rate. It actually changes the timing. Pop off rate is the amount of pressure required to push the needle open and pressurize the diaphragm area of the carb. By raising the fulcrum you risk over pressurization and the seat never closing. Sounds similar to why you had a hard time tuning it and it running rich. By cutting the spring the fulcrum can stay closed when not being used and still open at the correct time while allowing more responsive fuel delivery.

[@Fotopro]

Great videos. Can you please explain what the two smaller screw adjustments are for? I know one is for idol. I assume the other is for how rich you run the fuel. . What is the best way to tune the two together?

[@aaronpratt89]

sorry for the delay. there are 3 screws. one for low speed fuel, one for high speed fuel, and one for idle air. ill have to make a video on how i tune a carb, theres a lot to explain in text.

[@UnknoWnSaVaGe420]

What is the best setting for your carburetor

[@briang4470]

I'm surprised you didnt try an 813 carb with an accelerator pump if your looking for throttle response.

[@aaronpratt89]

I’ll get to that one one day lol. In my experience they tend to flood stock engines.

[@dawsonmacie6984]

@@aaronpratt89 the 813 was more impressive then i thought. I use it with small engines. Seems to help quite abit in the low end

[@aaronpratt89]

@@dawsonmacie6984 it’s next on the list for testing. Moving right now so videos are on hold for a bit lol

[@RKQUD]

What are the screw size for the carburator

[@offroadhooligans8701]

Why do you delete the choke?

[@aaronpratt89]

Well these engines tend to start easily with out using the choke. The choke plate itself restricts a small amount of air flow. So removing it helps this little engine breathe just a little bit better. However the only difference is super small and may only be noticed on a dyno.

[@godsun358]

New subscriber brother

[@donniep90]

What does cutting the metering spring do ?

[@aaronpratt89]

It lowered the pop off rate. Lowe pop off rate allows for sooner fuel delivery. Helps eliminate horrible throttle response.

[@donniep90]

@@aaronpratt89 gotcha ... Thanks for explaining that

[@godsun358]

Dang bruh you are good... My rc 5th scale with a wt668 carb is blowing bubbles in the fuel tank when I press the bulb. I recently changed fuel tank and carb, what did I do wrong 😕

[@aaronpratt89]

Bubbles are normal. When you push the primer bulb it pushes the air out of the fuel system to it the tank.

[@godsun358]

@@aaronpratt89 ok brother but I see there is no fuel going into carb bubble. Thanks for the reply and help

[@aaronpratt89]

@@godsun358 if it’s not picking up fuel, are your likes backwards?

[@aaronpratt89]

@@godsun358 it’s not a Chinese carb is it?

[@godsun358]

@@aaronpratt89 I thought so, I took off the one leading to carb and placed it where the 2nd line goes and put the 2nd line on carb and still nothing.

[@JayPlays792]

Nice work my guy i'm your 500th subscriber please tell me your on gopednation and gopedworld on facebook if not go go add yourself it will be epic!! I own a sport bigfoot and gsr46 hit me up!!

[@aaronpratt89]

Thanks man, I am on Goped nation lol