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Throttle body sync issue

6K views 9 replies 3 participants last post by  Flyers28 
#1 ·
Have a question for the knowledgeable as I admit I'm still learning to diagnose engines. Had to sync my throttle bodies and noticed that no matter how much I turned the screw in and out there would only be a negligible change in vacuum (using Morgan carbtune). So question I can't find an answer to is why this would be?

I figured the tools tubes were not sealed enough around the nipple. So I made sure that was not an issue and still same results.

The bikes at least a little smoother at rpm but it's not right because the bike sounds like a choked engine a few seconds on cold starts.

And yes I'm adjusting the right screws, done this a bunch of times with no issue.
 
#2 · (Edited)
did you blip the throttle a few times after you made an adjustment?

oddly enough the first time and the last time i tried to do my R6 it was with my buddy's morgan carb tune and I was experiencing the same thing. blipping the throttle like the manual said did seem to work.
I blamed it mostly on the tool since it uses metal rods instead of a liquid. i thought it just cant do small changes as well as a liquid.
 
#3 ·
Yep blip the throttle each time. I never had a problem with it and the tool always got nothing but great reviews. Maybe I will contact the company and see if it is tool related, but even so I would think the engine would change in tone or make some indication when the air screw is backed out or in fully.
 
#4 ·
Well I thought the vibration issues were solved at high rpm, but took it to the highway yesterday and its back. It's not just a buzz, but a pretty unnerving heavy vibration throughout the frame. Something is off and might be more than just a throttle body sync issue. Looks like I'm tearing apart the bike yet again. These are times were I would kill for a small motorcycle shop near me and not these rip off dealers that charge north of $80 to say it's all good when they know its not or worse try and convince you its x,y and z when clearly its not, uggh.

The cold start issue sounds like a fuel or air problem in one of the cylinders that eventually catches up and the bike starts to idle. But I don't get why its only when the bikes cold. If air can't access a cylinder through the throttle bodies at idle when the butterfly valves are closed why wouldn't that be an issue cold or hot. Same thing with fuel.
 
#6 ·
it doesn't sound like an idle problem to me. it sounds like an ignition or fuel delivery problem.
the sych only helps a bike idle. and barely at that with FI. this vibration does it feel like the motor or a wheel, tire or suspension. if it's speed related it's probably not the motor. unless it has an odd sound and has a loss of power.
 
#5 ·
Spoke with someone from Morgan and they agreed something seems strange. They said even the slightest movement of a screw should be enough to change the reading. They recommended using the tool upside down per the instructions for bikes like the R6 that pull a small vacuum. So I guess I'll give it another whirl for the 3rd time...but that's the charm right.
 
#8 ·
Alright so using the tool upside down helped and I could get the screws to move the gauge a bit, still couldn't get it spot on but I got other issues to fix first.

Still having cold start issues like I mentioned before. Still got a heavy spot in the engine. I've exhausted my knowledge so it looks like I will be giving the dealership my months paycheck. I put too many miles on this thing to spend each one worrying about the running condition of the bike. Just not enjoyable.
 
#10 ·
Woah thread revival, haha jk. Yea I did a compression check a while back and use a temp gun. Nothing out of the ordinary. Compression was slightly lower than the others in cylinder 2 but nothing alarming. Most of my problems have been fixed though since I posted this. I think originally the stealership did a horrible job adjusting my valves. The bike goes to a real mechanic this winter to get the valves sorted and anything in between. Will not have another summer where I 2nd guess putting 500 miles on it a weekend for fear of break down. But had it properly tuned by Bauce Racing which helped a lot, but I think combining that with valves that are properly adjusted will get her back to normal.
 
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