Synced my throttle bodies recently & came across this issue...both rear cylinder's screws are completely turned in, no adjustment range left. The right front cylinder still has adjustment. Left front is the standard. What happens when they won't sync the next go around?
Throttle body sync issue
- Thread starter ShawnD
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I'm not an expert on this by any means but I do have my throttle body's in hand atm. My guess is the rear throttle valves aren't closing as much as the front or possibly a vacuum leak somewhere. There is a adjustment screw for the rear plates next to the #1 throttle body. If you loosened that screw a tiny bit the rear plates would close and you should gain some adjustment in the air screws. I'd pay close attention to where that is set from the factory so it can be reversed if I'm wrong. Also make sure you don't go to far and cause the throttle plates to bind. It's the allen with the locknut not the Philips with the spring.
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So how much adjustment are we talking about, half a turn of the allen screw, 1/4 turn? Clockwise or counterclockwise?
I would start with 1/8th turn or less. It shouldn't take much to make a difference and more than that would likely cause the throttle plates to start binding. You wouldn't know how many turns your "master" air screw is turned out would you? I went to sync mine the other day and the previous owner had turned all the screws in all the way. That snowballed into removing and cleaning the throttle body's and injectors and some corrosion/paint repairs underneath them. I'm curious how that screw is set so I'd have a ballpark for mine.
That last reply got me thinking. Maybe someone messed with your master screw previously. That could explain why you ran out of adjustment. You might try marketing were that screw is and and turning it clockwise half a turn to see if you gain adjustment in the rear screws.
No idea but I bought the bike new. Yeah, I'm wondering how Yamaha determines what the reference screw is set to...I'm betting it's a specific vacuum reading. When I had a Bolt the service manual said to adjust the screw for the cylinder with the lower vacuum pressure but it also gave a minimum vacuum level for either cylinder. I'm almost tempted to adjust the reference cylinder & see how the bike reacts. But it synced this time around so I'm good for the moment. Guess I'll see what happens next time around.
Here you can read some useful info too Throttle body master sync screw . Until i not touched front left "master" cyl air screw, i was not able to sync all 4 cyls and i was little over allowed range with front left cyl. All 4 screws on my Vmax were untouched and all were set from factory to 1/8 turn before fully turned in. First i synced 3 non "master" cyls, then i synced "master" cyl and after that i gently adjusted all cyls. Now i have max difference between cyls about 1.5mmHg (allowed is 10mmHg) .
They were within 1/8 of a turn of fully seated? That doesn't leave much room for adjustment. Think I'm going to try your method next go around. Bike runs flawlessly so I'm not too concerned at this point.
Yes, 1/8 turn until fully seated, from factory. Without touching master screw there was no room for adjustment.
I ran across and old post of yours about your oil pressure gauge. I was wondering what you get for oil pressure at hot idle? Thanks
That was on a previous gen 2 & the memory aint as good as it used to be. I want to say it was around 10psi at idle when it was good & warmed up. This was with a 0-60 psi gauge. Was told the gauges rated for 0-100 weren't as accurate.
Thank you. Mine is getting down to 6-7 psi hot. I haven't found any cause yet. Pulled the oil pump and it had some light wear, pulled the oil pan and found a few tiny bits of non ferrous metal but nothing really concerning.
On a gen 2?
Yes
That makes me feel better. I had another post on here were I had shiny material in my oil. After pulling the pan I believe 99% of what I was seeing is clutch material. The clutch that's in it looks brand new. It came with a ackro mid pipe, pcv, and I believe a dyno tune. It didn't have the dd spring (it does now) and the clutch didn't slip at all. My theory at this point is the previous owner murdered the original clutch, changed it and sold it. However when I saw the oil pressure below spec I got concerned. It's easy to find all kinds of info on gen 1 oil pressure but not much on gen 2. Thanks for the reply
I put on a new pick up screen, had black plastic in it. Probably timing chain guide.
It's a bitch to remove the pick up screen. I put on a new screen because i couldn't get it apart with out destroying it. And the screen and mount was super cheap.
It's a bitch to remove the pick up screen. I put on a new screen because i couldn't get it apart with out destroying it. And the screen and mount was super cheap.
The only thing in my pickup screen was a bit of gasket material probably from when the PO changed the clutch. It cleaned right up
Does it pick up as soon as you start giving it some throttle? Also, what year is your gen 2?
It does pickup with rpm. I'm pretty sure it's fine now other than need the clutch material flushed out. Years ago Tim Nash was developing a oil pressure light (there's a video on utube) I sent him an email and he said he was getting 4psi at idle. The low pressure was part of the reason the light didn't work out. I know the 1st gens sometimes have 0 psi at idle. Being an Auto mechanic for 25 years the low pressure was alarming but it appears to be normal on these bikes. Makes sense I guess everything is so much lighter in the smaller engines I assume driving higher pressure just wastes HP. It's a 2009 btw and the recall has been done.
