SXR Carb Manifold Cross over tube fill

[rollin5150]

Just looking to gain some more knowledge on this. I do know that most engine builders do this mod when they port and engine and such. I was also told that it makes carbs easier to tune since one carb is now feeding one cylinder. Any other benefits to doing this? Is this mod better for a specific type on engine?

 

[Waternut]

Well more importantly than easier to tune carbs is the signal going to the carbs is stronger/cleaner. I forget what the advantage to having the crossover was but after doing the research, I remember thinking it was a no brainer to fill it on a modified engine.

 

[rollin5150]

Did a lot of searching and still on the fence whether or not this a worthwhile mod.

 

[Scorn800]

I've never done it to my sxr's. I know Groupk likes it. My boy has a hammer kit with it done.
I did run true bore carbs and Timmy Z told me not to do it.
What do you think you'll gain? what carbs you running?

 

[munki63]

Well more importantly than easier to tune carbs is the signal going to the carbs is stronger/cleaner. I forget what the advantage to having the crossover was but after doing the research, I remember thinking it was a no brainer to fill it on a modified engine.

100%
The crossover was designed for a smoother idle

 

[rollin5150]

I am just running the stock 38s right now. I was just more interested with why it was being done and what gains it will provide. My friend is having his yamaha carbs modified brapjack style and art is going to fill the cross over tube as well. I have read that it is a nightmare tuning sxr carbs after the fill is done

 

[munki63]

Im not an SXR guy but tuning carbs on a SJ and a SXR should be about the same, and it's not hard on the SJ just keep it simple, as far as what you will notice I'm gonna guess a stronger cleaner signal would primarily affect your throttle response... Also some food for thought I don't believe any of the new aftermarket manifolds have crossovers

 

[Patrick Star]

I'm leaving mine open. It's a Jetmaniac engine. Looks good sitting in the kitchen! :woot: Going to put it in the ski one of these days.

 

[Tyler Zane]

I'm leaving mine open. It's a Jetmaniac engine. Looks good sitting in the kitchen! :woot: Going to put it in the ski one of these days.

looks like ill have mine back together before you!

jetworks filled my crossover.

 

[rollin5150]

Im not an SXR guy but tuning carbs on a SJ and a SXR should be about the same, and it's not hard on the SJ just keep it simple, as far as what you will notice I'm gonna guess a stronger cleaner signal would primarily affect your throttle response... Also some food for thought I don't believe any of the new aftermarket manifolds have crossovers

I do not see why it would be any different either. I have read a few posts from some experienced guys having a real hard time dialing them in. I will see how my buddies Superjet does first

 

[munki63]

I do not see why it would be any different either. I have read a few posts from some experienced guys having a real hard time dialing them in. I will see how my buddies Superjet does first

I could be WAY off base but you tune both carbs pretty much the same... start 1 turn out and go from there, adjusting both the same accordingly... the only hard thing about adjusting the carbs vs a single carb is physically turning the dam needles

maybe its just me tho, im no expert lol

 

[Patrick Star]

looks like ill have mine back together before you!

jetworks filled my crossover.

You ain't kidding! All I do anymore is study and maybe tinker with one or two things a week on the ski. As of now my carbs are coming together and I did happen to get a nice green paint job on the inside of the hull with a TON of glitter in it, I need to put up some picts later. I did register my jon boat ski trailer today.

Welcome back home!!!!