Synchronizing the Throttlebodies

[Janne339]

From 2008 Nytro manual. But like Cannondale said, The Nytro throttle bodies are maybe different.

 

[Janne339]

The ports after throttle plate closest to air filter would be the ones to sync with. Nytro has different port location so does not apply to us. Keep going guys we need to analyze everything to figure out how to make this motor best it can be! Awesome work!

Hmm.. Are you sure about sync throttle bodies to port closest to air box? If these ports are connected before throttle valves (airbox-side)?

Maybe I understand wrong but if sync to the other ports, closest to engine, you got the vacuum of each cylinder?

 

[cannondale27]

Hmm.. Are you sure about sync throttle bodies to port closest to air box? If these ports are connected before throttle valves (airbox-side)?

Maybe I understand wrong but if sync to the other ports, closest to engine, you got the vacuum of each cylinder?

Yes you are correct. Was thinking flow guage. Corrected that statement.

 

[Dinner]

Ok so I uncapped one of the ports at the rear of the throttle body (closest to engine port, same hook up MCX is using) and with my mouth it is A LOT harder to pass air through that port. I went back to the front one (MPI hook up, farthest from engine) and it is definitely a lot easier to make air flow through that port.

Now, both ports can be heard through my intake tube and heard louder once the throttle is opened. It just the port MCX is using, is difficult to flow air compared to MPI ports. So now I'm not sure what to think!!!

 

[cannondale27]

Ok so I uncapped one of the ports at the rear of the throttle body (closest to engine port, same hook up MCX is using) and with my mouth it is A LOT harder to pass air through that port. I went back to the front one (MPI hook up, farthest from engine) and it is definitely a lot easier to make air flow through that port.

Now, both ports can be heard through my intake tube and heard louder once the throttle is opened. It just the port MCX is using, is difficult to flow air compared to MPI ports. So now I'm not sure what to think!!!

It could be the intake valves were closed. I will ask dealer if they still have the TB rack and if so map it out. Holes could ever be sized different. I know the one I could see was very small I'd.

 

[Dinner]

It could be the intake valves were closed. I will ask dealer if they still have the TB rack and if so map it out. Holes could ever be sized different. I know the one I could see was very small I'd.

Yeah perhaps! So maybe the rear ports are for behind the carb and front ports are for infront of carb. I agree bench testing one would be so much easier...but I wanted to go ride

Also my vacuum gauge is reading fine...10, 8 inHG at idle. I forgot my AEM's likes to see load/boost before it smartens up

 

[cannondale27]

Yes go ride! Thanks for all the work. I know it's not fun getting in there! Happy Trails!

 

[ateick]

It could be the intake valves were closed. I will ask dealer if they still have the TB rack and if so map it out. Holes could ever be sized different. I know the one I could see was very small I'd.

Bringing back an old thread but did you ever find out why two different sized vac ports on each carb?

 

[cannondale27]

Bringing back an old thread but did you ever find out why two different sized vac ports on each carb?

No. Yamaha took the rack back so couldn’t look.