SJ carburetor upgrade

[Ahmed AN9]

Hey guys I was wondering if i have to do somthing with the carbs after I upgraded the engine to 772cc and a FB pipe. Am using the stock 38's. Is there any probleme if i kept it as it is?

 

[Vumad]

@JetManiac runs 38s on a lot of his motors. Kawi 750s run 38s and 800s run 40s.

Cost is low if you get oem 44s, but they can burn substantially more fuel for not a lot of gain. It depends on how important the power is to you and how far you ride. I have 38s on my 701 limited Superjet and stock b1 but 44s on my limited x2. I have different priorities with the machines.

 

[erik mx45]

i put 46s on my ported 701 and i had big gains over 38s for my set up!

 

[Ahmed AN9]

I am thinking to go for racing in the next national tournament. So do you think that I only need to adjust my carbs with my new engine set-up without replacing anything?

 

[Lumpy]

Probably going to need to change jets.

 

[Ahmed AN9]

So, from what I understand that there will be no effect on the engine except the performance. But what do you recommend me to do with my stock carbs as long I switched from recreation to racing?

 

[Vumad]

So, from what I understand that there will be no effect on the engine except the performance. But what do you recommend me to do with my stock carbs as long I switched from recreation to racing?

Bigger carbs will make more power especially in racing. If you want to be competitive, upgrade to the most power you class allows that you can afford. If you are racing for fun, then 38s are acceptable and you decide the carbs based on your budget.

You probably have to rbe jet anytime you make any significant changes to your setup. Ask the builder who bored out your engine what specs they suggest. They are your best source for what size carbs to use as well. If it's a homebrew bore and port, then you need to do some research on what similar motor setups are using and proceeding with caution. Jetmaniac can probably tell you what he jets he motors and if you take his time to ask such questions then you should repay that advice by buying the parts you need from him.

 

[Ahmed AN9]

So Jetmaniac advice is not free. But I will go for whatever he said and I'll buy probably jettings from him. Thnx Vumad