Welcome to NESR! Most features of this site require registration, including replying to threads, sending private messages, starting new threads, and uploading files. Click here to register.

Page 3 of 3 FirstFirst 123
Results 51 to 60 of 60

Throttle bog at low RPM

  1. #51
    Lifer Wishbone's Avatar
    Join Date
    Jul 2006
    Location
    Worcester
    Age
    41
    Posts
    3,679

    Throttle bog at low RPM

    there is no in line filter between there and the carbs?

    0 Not allowed! Not allowed!
    ~ Life passes most people by while they're busy making grand plans for it.~

  2. #52
    Bikeless in Blackstone The Snowman's Avatar
    Join Date
    Jun 2006
    Posts
    12,538

    Throttle bog at low RPM

    Nope. It goes straight from the petcock to the carbs. No filter.

    0 Not allowed! Not allowed!
    CCS/LRRS Expert#39, retired | Tony's Track Days, Instructor #11, retired
    |

  3. #53
    Banned
    Join Date
    Aug 2001
    Posts
    15,160

    Throttle bog at low RPM

    There is a filter (strainer) in the top of the petcock assembly, inside the gas tank.

    The petcock has a vacuum hose that goes to it and when the carbs are running, the vacuum pulls a spring-loaded diaphragm to one side to allow fuel flow.

    It's possible I suppose that at those RPMs the vacuum isn't enough to pull the diaphragm because it has some crap in there that makes the diaphragm stick a little.

    I'm dying for you to find out what the hell this problem is. I'm wondering if the new fuels are damaging the rubber inside the petcocks and vacuum pumps. I have seen 3 of these type issues in the past month now. Every one on a carburetter bike with a petcock.

    derek

    Derek

    0 Not allowed! Not allowed!

  4. #54
    Bikeless in Blackstone The Snowman's Avatar
    Join Date
    Jun 2006
    Posts
    12,538

    Throttle bog at low RPM

    Quote Originally Posted by Degsy View Post
    There is a filter (strainer) in the top of the petcock assembly, inside the gas tank.

    The petcock has a vacuum hose that goes to it and when the carbs are running, the vacuum pulls a spring-loaded diaphragm to one side to allow fuel flow.

    It's possible I suppose that at those RPMs the vacuum isn't enough to pull the diaphragm because it has some crap in there that makes the diaphragm stick a little.

    I'm dying for you to find out what the hell this problem is. I'm wondering if the new fuels are damaging the rubber inside the petcocks and vacuum pumps. I have seen 3 of these type issues in the past month now. Every one on a carburetter bike with a petcock.
    Well, I pulled apart the petcock last weekend and it's fine. I did order a new diaphragm assembly and filter screen, because the screen looked like it was being twisted and sucked in toward the petcock's tube. Probably age and it's only plastic that's been sitting in gas for over 10 years. The diaphragm I'm replacing just in case. $43, shipped for the screen o-ring and diaphragm assembly, so it's not a huge expense.

    The rest of the petcock is metal, either aluminum or steel, so I doubt there's any breakdown.

    I'm anxious to solve this mystery as well. I want to ride!

    0 Not allowed! Not allowed!
    CCS/LRRS Expert#39, retired | Tony's Track Days, Instructor #11, retired
    |

  5. #55
    Kosher Assassin Stoneman's Avatar
    Join Date
    May 2001
    Location
    Center Barnstead, NH
    Posts
    1,128,390

    Throttle bog at low RPM

    Stator my friend. Stator...

    0 Not allowed! Not allowed!
    Did you grit your teeth and try to look like Clint Fuckin' Eastwood?
    Or did you lisp it all hangfisted like a fuckin' flower?

  6. #56
    Lifer
    Join Date
    Oct 2001
    Location
    Bedford, MA
    Posts
    5,233

    Throttle bog at low RPM

    Quote Originally Posted by Degsy View Post
    I'm dying for you to find out what the hell this problem is. I'm wondering if the new fuels are damaging the rubber inside the petcocks and vacuum pumps. I have seen 3 of these type issues in the past month now. Every one on a carburetter bike with a petcock.

    derek

    Derek
    You thinking the E10 fuel blends are causing this?

    There were warnings about it.

    0 Not allowed! Not allowed!

  7. #57
    Just Registered TLRMan's Avatar
    Join Date
    Jun 2001
    Location
    Northshore/Beverly, MA
    Age
    65
    Posts
    2,005

    Throttle bog at low RPM

    Sometimes it does go after the brass bits, and may attack the rubber stuff, but I've seen this problem with petcocks since the start of using vacuum to open them, so this isn't a new problem to me.

    I know what causes the 3-4k bogs and usually it's a quick fix.....if it's petcock related, I know how to test that one out too.
    If you brought the damn thing over to my place you'd be running good by now...
    ...and I can check the fuggin stator too.

    0 Not allowed! Not allowed!
    Too old to rock and roll, too young to die.

  8. #58
    Bikeless in Blackstone The Snowman's Avatar
    Join Date
    Jun 2006
    Posts
    12,538

    Throttle bog at low RPM

    Quote Originally Posted by TLRMan View Post
    Sometimes it does go after the brass bits, and may attack the rubber stuff, but I've seen this problem with petcocks since the start of using vacuum to open them, so this isn't a new problem to me.

    I know what causes the 3-4k bogs and usually it's a quick fix.....if it's petcock related, I know how to test that one out too.
    If you brought the damn thing over to my place you'd be running good by now...
    ...and I can check the fuggin stator too.
    Well, if the new screen and petcock diaphragm don't do the trick, I just might take you up on this.

    Damn stator is $250 new.

    0 Not allowed! Not allowed!
    CCS/LRRS Expert#39, retired | Tony's Track Days, Instructor #11, retired
    |

  9. #59
    Member jamotech741's Avatar
    Join Date
    Jul 2007
    Location
    NH
    Posts
    165

    Throttle bog at low RPM

    Ive never been a carb guy, but I do have limited experience with carbs. It sound like a flat spot that is "usually" fuel related. However I am familiar with cbrs and their stator problems, but "usually" it is also having problems with dying batteries if its a stator. If its not the stator which is easy to check, Id say its a fuel issue. Most likely not an ignition problem unless the stator is acting up causing voltage problems that can affect the igntion system. Paul D and tlrman are leading you on the correct path to diagnosis. Good Luck!

    0 Not allowed! Not allowed!

  10. #60
    Bikeless in Blackstone The Snowman's Avatar
    Join Date
    Jun 2006
    Posts
    12,538

    Throttle bog at low RPM

    Thanks. I'm still waiting on the filter screen and petcock diaphragm.

    As far as the charging system goes, the battery seems to be fine. The bike hasn't died while running.

    0 Not allowed! Not allowed!
    CCS/LRRS Expert#39, retired | Tony's Track Days, Instructor #11, retired
    |

Page 3 of 3 FirstFirst 123

Similar Threads

  1. whiskey throttle
    By breakdirt916 in forum Dirty Bastards
    Replies: 6
    Last Post: 03-25-13, 05:51 PM
  2. Replies: 59
    Last Post: 12-24-11, 12:12 PM
  3. need a duc throttle..
    By landricscustoms in forum Wanted
    Replies: 4
    Last Post: 09-20-10, 11:07 AM
  4. R1 throttle mod
    By Jim in forum General Bike Related
    Replies: 46
    Last Post: 04-10-08, 02:29 PM
  5. throttle mod?
    By akira700 in forum General Bike Related
    Replies: 15
    Last Post: 11-15-06, 11:36 AM

Posting Permissions

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