Super Jet epoxing intake manifold

[JPCharmin]

My buddy was told that doing this would create alot of bottom end, would this be so? He has dual 38's

 

[Matt_E]

It's called filling the cross-over.
You need to make sure that it's epoxied all the way. It needs to be flush with the rest of the metal.
In the picture, it doesn't look like there is enough epoxy.

 

[JPCharmin]

ok cool i'll pass the info along, but is it a mod that will make a noticeable difference?

 

[Matt_E]

I can't say, I've never tried that on identical setups back to back.

 

[Crab]

I wouldn't unless your modding the carb like Jetworks does, his jetting is based on the fill.

 

[aramis]

I wouldn't do this unless you are 110% comfortable tuning carbs...jetting, pop-off pressure, etc. should all be things you don't mind playing with.

 

[BruceSki]

heres how mine came out. I bolted the motor together then took it all back apart to build an ss865. Never got to run it. Still have it on the shelf.

 

[Freakrider]

John at JSS is adamant about his stance on this subject...he states that filling in the crossover is a mistake and maintains that there is better carb signal / low end hit with the crossover...it is my understanding that Yamaha added the crossover because it helps tune low speed/smooth out the idle...

 

[Cannibal]

John at JSS is adamant about his stance on this subject...he states that filling in the crossover is a mistake and maintains that there is better carb signal / low end hit with the crossover...it is my understanding that Yamaha added the crossover because it helps tune low speed/smooth out the idle...

Hmm, interesting. I'd like to hear more opinions on the subject.

 

[scotts2t]

All the a/m intakes for running 44mms+ have no crossover.

 

[Freakrider]

All the a/m intakes for running 44mms+ have no crossover.

However, the stock 44mm intake does have the crossover. Also reported to help attenuate the unwanted pressure waves in the intake. If I recall correctly, John at JSS did back to back comparison testing and claims the crossover intake performs better...

I am not convinced this is true (I run a R&D intake) but it is very interesting when you here John explain it...

 

[scotts2t]

Im not conviced either. I have r&d duel aswell. It allows me to keep the cylinders at slightly different jetting specs eg. The rear needs a bit more fuel than the front because it works harder. Keeping them separate seems more accurate to me.

 

[FearMyWrX]

Im not conviced either. I have r&d duel aswell. It allows me to keep the cylinders at slightly different jetting specs eg. The rear needs a bit more fuel than the front because it works harder. Keeping them separate seems more accurate to me.

That makes perfect sense. I just let Art At BlackJack Performance do his thing, got it filled.

 

[augustaf]

The crossover seems to work well on the stock 38 set-up, however when I tried a 44mm oem 760 carb / manifold on a superjet, I was unable to tune the carbs til I filled in the crossover!

 

[hoopsnap]

just going to throug this out there. yamahas famed banshee 350 two stoke uses a crossover tube, called a boost tube. aftermarket boost tubes are an even larger chamber then the stock, and they add more torque............ my addvice? leave it alone, possible make the internal chamber larger but do not open up the original openings.

 

[Mark44]

The crossover seems to work well on the stock 38 set-up, however when I tried a 44mm oem 760 carb / manifold on a superjet, I was unable to tune the carbs til I filled in the crossover!

same here.

 

[#ZERO]

The stock 38s only have one fuel pump so there's really no need to fill the intake crossover on the dual 38mm manifolds unless you want to install an extra fuel pump.

 

[SUPERJET-113]

Im not conviced either. I have r&d duel aswell. It allows me to keep the cylinders at slightly different jetting specs eg. The rear needs a bit more fuel than the front because it works harder. Keeping them separate seems more accurate to me.

^^ Exactly why I do it.
Why do you think aftermarket intakes have no crossover...

 

[Matt_E]

Probably because it would take more work to do. :lmao:

 

[SUPERJET-113]

LOL, yeah thats it, thats the ticket, yeah....(Jon Lovitz voice)

My last one was a OEM dual 44 intake that I filled the crossover tube with JB weld and ground/sanded it perfectly flush and then epoxied in bolts up through the upper carb base mounting piece and put on dual BrapJack 44's. That w/Vforce II and R&D 3° angled reed spacer worked killer!