Page 9 of 10 FirstFirst ... 78910 LastLast
Results 121 to 135 of 148

Thread: Idling @ 8000 rpm

  1. #121
    Join Date
    16th September 2009 - 11:05
    Bike
    '99 GSX750F, FXR150 bucket, RMX250
    Location
    Palmerston North
    Posts
    455
    Quote Originally Posted by RDjase View Post
    CRC or WD40 sort of does the same job as Ether, it just seals the air leaks when it is sprayed on and sucks it thru the vacuum leak/leaks.

    Ether does work better and wont make the manifolds slippery as you want to seal them with RTV

    Getting closer mate
    Ah OK, yeah Ducatilover gave the inlet manifolds a liberal soaking with CRC, didn't make any difference.

    Have degreased the rubbers and manifolds, all shiny smooth and good as new.

    Yup getting there! Will report back after I've tried the carbs with a bit of sealant.

    Cheers all!

  2. #122
    Join Date
    17th July 2005 - 22:28
    Bike
    Dougcati, Geoff and Suzi
    Location
    Banjo town
    Posts
    10,162
    It was worth the beer.
    I'll give my brain a bit more of a work out and see if anything pops into my mind.
    Thankfully there wasn't any sign of condensation in the oil cbfb has dropped out of the bike. I couldn't find any signs of a decent air leak. Carb #4 had the float level set as high as fuck, which seemed to indicate why it would piss out of number four.
    I'll bring the hammer next time, I have to use it on the CB tomorrow, it's decided to start missing like a pig.
    Quote Originally Posted by Paul in NZ View Post
    Ha...Thats true but life is full horrible choices sometimes Merv. Then sometimes just plain stuff happens... and then some more stuff happens.....




    Alloy, stainless and Ti polishing.
    Bling your bike out!
    PM me

  3. #123
    Join Date
    13th September 2005 - 18:20
    Bike
    Crashed it.
    Location
    Auckland
    Posts
    2,043
    Quote Originally Posted by cbfb View Post
    Well a bit of an update... Ducatilover came over yesterday to have a look at it, we got the fuel leak sorted I think, needed the float height adjusting on one of the carbs. Bit strange as it was only out on one carb, but anyway it doesn't seem to be leaking anymore.
    So you didn't check the float levels after you reassembled the carbs? That's a fundamental error. Any time you disturb them even by just removing the float bowl they MUST be checked. For the high fuel level to have been a cause of the overflowing fuel, the float would have to have contacted the carb body before the float valve seated. That's a LONG way out. Methinks you've not seen the last of that issue.

    Quote Originally Posted by cbfb View Post
    Last remaining issue is that once the bike is warmed up, the white exhaust appears (doesn't do it when cold) and the idle gradually increases on its own from around 1500 to around 2500. We were thinking it might be an air leak, the carb rubbers look mint but I'm gonna replace them with a thin layer of sealant to see if that helps.
    An idle speed of that magnitude if the butterflies are indeed closed does indicate an air leak, unlike 8000rpm.
    If it wasn't for a concise set of rules, we might have to resort to common sense!

  4. #124
    Join Date
    16th September 2009 - 11:05
    Bike
    '99 GSX750F, FXR150 bucket, RMX250
    Location
    Palmerston North
    Posts
    455
    Quote Originally Posted by ducatilover View Post
    It was worth the beer.
    I'll give my brain a bit more of a work out and see if anything pops into my mind.
    Thankfully there wasn't any sign of condensation in the oil cbfb has dropped out of the bike. I couldn't find any signs of a decent air leak. Carb #4 had the float level set as high as fuck, which seemed to indicate why it would piss out of number four.
    I'll bring the hammer next time, I have to use it on the CB tomorrow, it's decided to start missing like a pig.
    I have a fine selection of hammers, 8 at the last count

    Quote Originally Posted by Max Preload View Post
    So you didn't check the float levels after you reassembled the carbs? That's a fundamental error. Any time you disturb them even by just removing the float bowl they MUST be checked. For the high fuel level to have been a cause of the overflowing fuel, the float would have to have contacted the carb body before the float valve seated. That's a LONG way out. Methinks you've not seen the last of that issue.

    An idle speed of that magnitude if the butterflies are indeed closed does indicate an air leak, unlike 8000rpm.
    Ah, the tab was only slightly bent, I didn't realise they were that sensitive. Another lesson learnt. What makes you say it will be coming back? I do wonder about that carb maybe I need to replace it.

    Good, will see how I get on with the sealant.

  5. #125
    Join Date
    13th September 2005 - 18:20
    Bike
    Crashed it.
    Location
    Auckland
    Posts
    2,043
    Quote Originally Posted by cbfb View Post
    Ah, the tab was only slightly bent, I didn't realise they were that sensitive. Another lesson learnt. What makes you say it will be coming back? I do wonder about that carb maybe I need to replace it.

    Good, will see how I get on with the sealant.
    They're sensitive in that a lot of float movement is required in order to move the float valve a little because of the distance from the pivot of the float compared to the distance to the valve. This is to some degree done to damp the float movement due to the fuel movement and also to centralise the floats forward and aft at a point at which the fuel level doesn't particularly vary. But I digress.

    All I'm saying is that I doubt the float level was the real reason for the overflowing fuel because it has to be a long way out to do that.

    I'm not sure where you're planning on using the sealant exactly, so I'll say this: Go very easy on the sealant.

    Given the very nature of the carbs going inside the rubbers any sealant you were to use there (which I simply wouldn't - ever) is unlikely to make any difference anyway - sealant works on face-to-face contact - just fitting the carbs into the rubbers will remove most of it.

    Using sealant on the face of the rubbers where they connect to the head will really be masking the fault and it will come back so if successful you still need to find where the air leak actually is because it will grow if it's a crack in the rubbers. So largely that would be a wasted effort.

    I take it you've actually checked all the rubbers where they connect to the head for leaks on that face?
    If it wasn't for a concise set of rules, we might have to resort to common sense!

  6. #126
    Join Date
    16th September 2009 - 11:05
    Bike
    '99 GSX750F, FXR150 bucket, RMX250
    Location
    Palmerston North
    Posts
    455
    Quote Originally Posted by Max Preload View Post
    They're sensitive in that a lot of float movement is required in order to move the float valve a little because of the distance from the pivot of the float compared to the distance to the valve. This is to some degree done to damp the float movement due to the fuel movement and also to centralise the floats forward and aft at a point at which the fuel level doesn't particularly vary. But I digress.

    All I'm saying is that I doubt the float level was the real reason for the overflowing fuel because it has to be a long way out to do that.

    Go very easy on the sealant. Given the very nature of the carbs going inside the rubbers it's unlikely to make any difference anyway - sealant works on face-to-face contact - just fitting the carbs into the rubbers will remove most of it.

    I take it you've actually checked all the rubbers where they connect to the head for leaks on that face?
    Ah OK. It seems that whoever owned the bike previously had set the float on this one carb way high; Ducatilover & I set it back to normal, still overflowing so went a bit the other way so floats are sitting low in order for the needle to close earlier.

    Yep I will use the sealant sparingly.

    We sprayed CRC around but didn't notice anything. I haven't got a can of ether, could go buy some, any other method you could recommend?

  7. #127
    Join Date
    13th September 2005 - 18:20
    Bike
    Crashed it.
    Location
    Auckland
    Posts
    2,043
    Quote Originally Posted by cbfb View Post
    Ah OK. It seems that whoever owned the bike previously had set the float on this one carb way high; Ducatilover & I set it back to normal, still overflowing so went a bit the other way so floats are sitting low in order for the needle to close earlier.
    In what way were they set to 'normal' - just a measurement from the bottom of the float to the carb body float bowl base? Have you also verified the actual fuel levels in the bowls are correct?

    At the end of the day if it's overflowing you have either a leaking float valve or the float valve seat body o-ring (the one where Viton was discussed). There's no other way for the fuel to enter the float bowl.

    Quote Originally Posted by cbfb View Post
    We sprayed CRC around but didn't notice anything. I haven't got a can of ether, could go buy some, any other method you could recommend?
    We used to use an 9kg LPG bottle with a hose off a regulator and a copper rigid end to poke around and accurately locate vacuum leaks. Just do it in a well ventilated area like outside so the gas concentration doesn't build up and get to potentially explosive concentrations.
    If it wasn't for a concise set of rules, we might have to resort to common sense!

  8. #128
    Join Date
    17th July 2005 - 22:28
    Bike
    Dougcati, Geoff and Suzi
    Location
    Banjo town
    Posts
    10,162
    Quote Originally Posted by Max Preload View Post

    We used to use an 9kg LPG bottle with a hose off a regulator and a copper rigid end to poke around and accurately locate vacuum leaks. Just do it in a well ventilated area like outside so the gas concentration doesn't build up and get to potentially explosive concentrations.
    That's a neat idea.
    Before the cabs go on, perhaps you should do the float height cbfb?
    http://www.factorypro.com/tech/carbt...m_engines.html
    This may help a wee bit.
    Quote Originally Posted by Paul in NZ View Post
    Ha...Thats true but life is full horrible choices sometimes Merv. Then sometimes just plain stuff happens... and then some more stuff happens.....




    Alloy, stainless and Ti polishing.
    Bling your bike out!
    PM me

  9. #129
    Join Date
    16th September 2009 - 11:05
    Bike
    '99 GSX750F, FXR150 bucket, RMX250
    Location
    Palmerston North
    Posts
    455
    Quote Originally Posted by Max Preload View Post
    In what way were they set to 'normal' - just a measurement from the bottom of the float to the carb body float bowl base? Have you also verified the actual fuel levels in the bowls are correct?

    At the end of the day if it's overflowing you have either a leaking float valve or the float valve seat body o-ring (the one where Viton was discussed). There's no other way for the fuel to enter the float bowl.

    We used to use an 9kg LPG bottle with a hose off a regulator and a copper rigid end to poke around and accurately locate vacuum leaks. Just do it in a well ventilated area like outside so the gas concentration doesn't build up and get to potentially explosive concentrations.
    Yes that is how I checked float height and no I havent checked actual levels as I didn't know how.

    Quote Originally Posted by ducatilover View Post
    That's a neat idea.
    Before the cabs go on, perhaps you should do the float height cbfb?
    http://www.factorypro.com/tech/carbt...m_engines.html
    This may help a wee bit.
    OK will do...

  10. #130
    Join Date
    18th June 2010 - 19:27
    Bike
    honda vtr1000
    Location
    Auckland
    Posts
    28
    are the slide diaphrams in the carbs in good condition? have you checked if they have a hole or a small tear? with regards to idling?

  11. #131
    Join Date
    16th September 2009 - 11:05
    Bike
    '99 GSX750F, FXR150 bucket, RMX250
    Location
    Palmerston North
    Posts
    455
    Quote Originally Posted by disorderly View Post
    are the slide diaphrams in the carbs in good condition? have you checked if they have a hole or a small tear? with regards to idling?
    I gave the diaphragms a visual check when I had them out. Slide/diaphragm operation looks/sounds as you'd hope - Ducatilover will agree with me there I'm sure.

    Well I've decided this has gone on long enough, I want to ride the bloody thing while it's still summer! So will:

    - Check/adjust float height
    - Refit carbs with sealant
    - Warm up
    - Use ether to check for leaks if still idling funny

    If none of that gets me anywhere, and if this white smoke persists, I think I'm gonna have to take it down the road to the garage . Should be OK to ride that short distance as is...

  12. #132
    Join Date
    11th February 2010 - 10:01
    Bike
    1994 Yamaha Zeal
    Location
    Christchurch
    Posts
    1,030
    Quote Originally Posted by cbfb View Post
    I gave the diaphragms a visual check when I had them out. Slide/diaphragm operation looks/sounds as you'd hope - Ducatilover will agree with me there I'm sure.

    Well I've decided this has gone on long enough, I want to ride the bloody thing while it's still summer! So will:

    - Check/adjust float height
    - Refit carbs with sealant
    - Warm up
    - Use ether to check for leaks if still idling funny

    If none of that gets me anywhere, and if this white smoke persists, I think I'm gonna have to take it down the road to the garage . Should be OK to ride that short distance as is...
    You've given her a great crack by the looks of things, even if it doesn't work you've learned about your bandit and how it works. I have no idea about how my bike works...
    Quote Originally Posted by White trash View Post
    I'd rather eat cat shit with a knitting needle than go to Green Day

  13. #133
    Join Date
    16th September 2009 - 11:05
    Bike
    '99 GSX750F, FXR150 bucket, RMX250
    Location
    Palmerston North
    Posts
    455
    Quote Originally Posted by Gibbo89 View Post
    You've given her a great crack by the looks of things, even if it doesn't work you've learned about your bandit and how it works. I have no idea about how my bike works...
    Yeah mate, it's been a learning experience but sometimes you've got to admit you're out yer depth!! Could probably sort it out eventually but too much on atm, just want to ride. Plan is to buy another machine eventually, one to tinker with and one that's working.

    Cheers

  14. #134
    Join Date
    11th February 2010 - 10:01
    Bike
    1994 Yamaha Zeal
    Location
    Christchurch
    Posts
    1,030
    Quote Originally Posted by cbfb View Post
    Yeah mate, it's been a learning experience but sometimes you've got to admit you're out yer depth!! Could probably sort it out eventually but too much on atm, just want to ride. Plan is to buy another machine eventually, one to tinker with and one that's working.

    Cheers
    What was you previous experience with small engines?
    Quote Originally Posted by White trash View Post
    I'd rather eat cat shit with a knitting needle than go to Green Day

  15. #135
    Join Date
    17th July 2005 - 22:28
    Bike
    Dougcati, Geoff and Suzi
    Location
    Banjo town
    Posts
    10,162
    Get into it man! Take it up the road anyway.
    A compression check may be in order if there's still a gay idle, but, setting the floats could have something to do with it too.
    Quote Originally Posted by Paul in NZ View Post
    Ha...Thats true but life is full horrible choices sometimes Merv. Then sometimes just plain stuff happens... and then some more stuff happens.....




    Alloy, stainless and Ti polishing.
    Bling your bike out!
    PM me

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Posting Permissions

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