Yamaha G1 bigger carb?

[dirtbikeguy2003]

I would like to put a bigger carb on my G1. I rebuilt the engine it runs good but would like some more power. I have read that people use blaster carbs, How are they running the throttle and choke? What about the intake boot and reeds? Is there a kit from someone or is it a piece together? I have tried searching but havent fount the exact answers.

Thanks Howie

[TheNewGuy]

Welcome to BGW!

IMO these kinds of mods are a lot of trial and error. Try doing a search on here to find more info.

[sho305]

People have done it, larger will give more topend at expense of bottom end. Be careful of jetting you can burn the piston with a 2 stroke going too lean. It needs some other things to really run though, just a carb only helps so much. Advance the timing, cut the head, raise the port a hair, clutch it up, then it should run better if the top end is in good shape. If compression is low bore it first. You can use other pipes too but again lots of trial and error, some used a banshee pipe on them.

[dirtbikeguy2003]

I have good compression and the kart runs well. Do you know how they fit a banshee pipe? I have a set of stock banshee pipes at my dads house but they dont look like they will fit very easily.

[sho305]

It should work, there are threads on it one guy had a yellow jeep front on his G1 and did a lot of work on it....might have posted what carb he used but you would have to do some digging. In fact I might have been on BU back then. The pipe all I know is one side fits it somehow, you may have to weld the header from the stock pipe onto it if size is different and to aim it better. It will be for much higher rpm, you can try to make the header longer that will tune rpm lower. If you want to get creative find an old bravo yamaha sled and put that 250 engine in there, the ignition fits and it runs pretty strong.

[Freezeman]

On mine when I first rebuilt the motor I fitted a WB20 Walbro with a velocity stack and K&N. I also did some head and port work along with eliminating the oil injection and choke.
Even with the stock pipe the motor came to life well enough that I took the Walbro off as I didn't want someone blowing up the motor from over revving it as it would rev some much that you could hear the poor bottom end asking for some mercy.
I ended up boring the stock carb out a bit and eliminating the coke butterfly and thinned the throttle butterfly,shaft and screw which made the stock carb with a K&N flow a bit more and tamed down the top rpm's the motor would twist to.
I don't use a choke and only miss it in the cold early mornings to take the trash can down to the Highway. A squirt nozzle choke would be nice for cold days as it wouldn't impair the flow . The throttle is hooked directly the the gas peddle.

[GMB74]

Pix of a Banshee exhaust setup I picked off the forum somewhere.

Link to my G1 bigblock project:
http://www.buggiesgonewild.com/big-b...lockin-g1.html

Search for posts by Tikicart, he has done some modding on G1's.