Page 5 of 14 FirstFirst ... 34567 ... LastLast
Results 41 to 50 of 132

Thread: Engine Fluttering Sound

  1. #41
    Senior Member rippin209's Avatar
    Bike: 2012 NC700X
    Join Date
    Jan 2016
    Location
    US
    Posts
    1,415
    Hearing that the throttle body was loose is an odd problem but explains the symptoms. I remember reading this thread awhile back and recently had similar problems.
    No noticeable power loss but it felt like riding something with a carburetor with the choke on our when it's cold.
    Not noticeable (at least to me) at an idle or when above 4,000 rpm but under load (when riding) it was definitely not right.
    I thought bad gas or a vacuum leak so I take out the air filter and there's a small gasket on both the top half and bottom half of the air box and part of it was out of place, lined it all up put it back together (did the EFI reset) and sure enough problem is gone.

    It doesn't take much to make a noticeable difference on the NC apparently

  2. #42
    Senior Member
    Bike: '12 NC700XC
    Join Date
    Nov 2012
    Location
    Arizona, USA
    Posts
    1,598
    Intake tract leak could easily swamp the ECU's demand (control) authority to adjust pulse width on the injectors.

  3. #43
    Commuter Extraordinaire Engine Fluttering Sound
    Engine Fluttering Sound
    SergeantChuck's Avatar
    Bike: NC700X
    Join Date
    May 2013
    Location
    Cabot, AR
    Posts
    3,803
    Both Friday and Saturday, I sprayed starting fluid all around the throttle body area with no reaction by the engine. I even expanded the spraying a little further than the throttle body and still nothing. Looking like it is not a vacuum leak. My next step will probably be to change the injectors and fuel rail.

  4. #44
    Commuter Extraordinaire Engine Fluttering Sound
    Engine Fluttering Sound
    SergeantChuck's Avatar
    Bike: NC700X
    Join Date
    May 2013
    Location
    Cabot, AR
    Posts
    3,803
    Quote Originally Posted by rippin209 View Post
    I thought bad gas or a vacuum leak so I take out the air filter and there's a small gasket on both the top half and bottom half of the air box and part of it was out of place, lined it all up put it back together (did the EFI reset) and sure enough problem is gone.

    It doesn't take much to make a noticeable difference on the NC apparently
    I'll take a look at this. I have had the air box apart many times and could have missed that but I think it is good. I have also done the EFI reset. I did not try a reset after fixing the throttle body leak.

  5. #45
    Commuter Extraordinaire Engine Fluttering Sound
    Engine Fluttering Sound
    SergeantChuck's Avatar
    Bike: NC700X
    Join Date
    May 2013
    Location
    Cabot, AR
    Posts
    3,803
    Quote Originally Posted by rippin209 View Post
    Hearing that the throttle body was loose is an odd problem but explains the symptoms. I remember reading this thread awhile back and recently had similar problems.
    No noticeable power loss but it felt like riding something with a carburetor with the choke on our when it's cold.
    Not noticeable (at least to me) at an idle or when above 4,000 rpm but under load (when riding) it was definitely not right.
    I thought bad gas or a vacuum leak so I take out the air filter and there's a small gasket on both the top half and bottom half of the air box and part of it was out of place, lined it all up put it back together (did the EFI reset) and sure enough problem is gone.

    It doesn't take much to make a noticeable difference on the NC apparently
    Just wanting some clarification. I took the air box back out. You said something about a small gasket on both the top half and bottom half of air box. I see the gasket in the bottom half of the air box but the top half is supposed to have one too? I did not see one BUT I really did not look that hard. I will take a good look tonight.

  6. #46
    Commuter Extraordinaire Engine Fluttering Sound
    Engine Fluttering Sound
    SergeantChuck's Avatar
    Bike: NC700X
    Join Date
    May 2013
    Location
    Cabot, AR
    Posts
    3,803
    I finally got around to swapping the injectors. What a PITA. There is no room in that area. The wiring harness clips to the fuel rail which complicates things and the electrical connectors have a large rubber cover which in my case made it hard to press the release lever hard enough for it to click so I could pull the connector free.

    The hose between the throttle body and the intake could not be removed because of how they positioned the clamp. I cannot get a wrench, socket, or screwdriver on that fasteners to loosen it so wiggling the fuel rail past that was tough. I got the new injectors in place and will reinstall the throttle body tonight.

    Cross your fingers. I hope this fixes my problem.

  7. #47
    Senior Member rippin209's Avatar
    Bike: 2012 NC700X
    Join Date
    Jan 2016
    Location
    US
    Posts
    1,415
    Quote Originally Posted by SergeantChuck View Post
    Just wanting some clarification. I took the air box back out. You said something about a small gasket on both the top half and bottom half of air box. I see the gasket in the bottom half of the air box but the top half is supposed to have one too? I did not see one BUT I really did not look that hard. I will take a good look tonight.
    There is two Part #4 one above the filter and one below (one for the box and one for the lid)

  8. #48
    Commuter Extraordinaire Engine Fluttering Sound
    Engine Fluttering Sound
    SergeantChuck's Avatar
    Bike: NC700X
    Join Date
    May 2013
    Location
    Cabot, AR
    Posts
    3,803
    Quote Originally Posted by rippin209 View Post
    There is two Part #4 one above the filter and one below (one for the box and one for the lid)
    I found the second seal/gasket the same day. Finally decided to remove the filter and look in that grove. Thank for the reply.

  9. #49
    Commuter Extraordinaire Engine Fluttering Sound
    Engine Fluttering Sound
    SergeantChuck's Avatar
    Bike: NC700X
    Join Date
    May 2013
    Location
    Cabot, AR
    Posts
    3,803
    Well, if anyone is following this story, the injectors did not help. Still having the same issue. I post all this just in case someone else has the same problem in the future.

    In my mind, this leaves one of two things. Just maybe, it could have something to do with the Throttle Position Sensor or it is a partially restricted fuel filter which is lowering my fuel pressure and it the engine is not getting supplied enough fuel. I'm looking into a way to test the fuel pressure. I spoke with a fellow worker and was told he might have a fuel pressure tester that has some sort of a "tap" that is used jump between the fuel line and the fuel rail. He is checking to see if he still has it.

    I'm going to pull the new spark plugs and take another look since it has been ridden on those plugs for about 200 miles. I want to see if it is in fact running lean. I have a bad feeling I'm going to have to pull the tank and replace the fuel pump/filter. If/when I do this, I will try to take some photos since I'm not sure I have seen any posted on the site.

  10. #50
    Senior Member Jt105's Avatar
    Bike: 2015 NC700X, 2012 ST1300A
    Join Date
    May 2018
    Location
    Michigan, USA
    Posts
    419
    You’ve done a lot of work chasing this problem. When you checked the valves, did you verify the cam timing to see if the cam chain skipped a tooth?

    JT

Similar Threads

  1. Sound from engine area
    By QuaXum in forum Garage / Mechanical Help
    Replies: 34
    Last Post: 26th June 2018, 19:18
  2. Loud ticking sound from Engine area
    By sk8norcal in forum Garage / Mechanical Help
    Replies: 23
    Last Post: 12th June 2018, 03:36
  3. Replies: 35
    Last Post: 12th October 2016, 12:43
  4. Intermittent Engine Shutting off. (not engine failure)
    By Disastrous in forum Garage / Mechanical Help
    Replies: 30
    Last Post: 26th June 2015, 18:55
  5. check engine didn't go away after engine start
    By wildeone in forum NC750 Technical
    Replies: 3
    Last Post: 8th June 2015, 04:47

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •