96 Trophy 900...(third????) Bad Petcock?

Discussion in 'Technical Help' started by thom wessels, Dec 30, 2020.

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  1. thom wessels

    thom wessels New Member

    Dec 23, 2020
    5
    3
    Wildomar, CA
    Many trips to the shop to get the bike to stay running. Bought 2 new petcocks, now working on #3. Last shop got it all set and it finally stayed running....until after a 200 mile ride. Again, it wouldn't stay running more than a couple minutes, apparently until the float bowls are empty. I've tried to put it on 'prime' when that happens but still don't have much luck keeping it running. Apparently, the petcock is NOT working right AGAIN.

    Is there any other way to test the 'suction safety function' of the petcock? The suction hose is hooked up but I don't think it's having any effect. If I run a hose directly to the carbs, it stays running.

    Anyone know how to fit a different blasted petcock than the one that's there OEM? I'm tired of shelling out $140. each time a BRAND NEW petcock goes south. I'm almost ready the take a vice grips on the hose to shut it off.

    Thanks for any help.
    Thom W
    1996 Trophy 900
     
  2. capt

    capt Elite Member

    May 8, 2016
    3,052
    750
    western Australia
    Try the breather in the tank Cap.
    If it's blocked it will cause those symptoms.
    Bike will run for a while then vacuum will build in the tank~ ergo fuel flow stops
     
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  3. thom wessels

    thom wessels New Member

    Dec 23, 2020
    5
    3
    Wildomar, CA
    I'll look at that. I guess I could just leave the cap loose as a quick check.
    Thanks
    Thom W
     
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  4. Sprinter

    Sprinter Kinigit

    Aug 17, 2014
    6,026
    1,000
    uk
    Would be safe to say it is not the Petcock then. Have you looked at the carbs, cleaning the vacuum channels?
     
  5. sprintdave

    sprintdave Nurse,he's out of bed again

    May 25, 2014
    1,491
    750
    Birmingham
    Make sure you haven't kinked the fuel line under the tank when you put it back on. Very easy to do.
     
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  6. thom wessels

    thom wessels New Member

    Dec 23, 2020
    5
    3
    Wildomar, CA
    Not sure how to check the vacuum channel, unless I maybe blow air down through the vertical tube where the vacuum is tapped to the carb. The carbs were 'cleaned' (every time it was worked on) and 'rebuilt' about 3 times, according to every shop it's been to... I'll try that.

    Thom
     
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  7. thom wessels

    thom wessels New Member

    Dec 23, 2020
    5
    3
    Wildomar, CA
    I actually can see that the vacuum line had a kink in it where it exits under the big frame tube and connects to the petcock. That would certainly be a cause for no vacuum!

    nb: the last shop STILL didn't hook up the new petcock like it was designed to be connected. Example: The forward facing petcock tube is connected as well as the vacuum line. The rear facing petcock tube however is capped off. That can't be right.....right??

    Thom
     
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  8. Sprinter

    Sprinter Kinigit

    Aug 17, 2014
    6,026
    1,000
    uk
    Put your finger over the vacuum tube, you should feel a pulsing suck ( said the actress to the Bishop).Not strong but constant.
     
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  9. thom wessels

    thom wessels New Member

    Dec 23, 2020
    5
    3
    Wildomar, CA
    #9 thom wessels, Dec 31, 2020
    Last edited: Dec 31, 2020
    .
    Yes, there's slight but noticeable suction. I'm putting it all back together tomorrow, watching the suction tube for kinks.

    What do you think about the capped - off rear facing petcock outlet? Is that the 'reserve' tube? If so, that would mean that even when I figure out the trouble, I still won't have the option of switching to 'reserve', if I'm reading this correctly

    Thom W
     
  10. Sprinter

    Sprinter Kinigit

    Aug 17, 2014
    6,026
    1,000
    uk
    The reserve is a different tube within the tank, so as to take fuel from lower down in the tank, not so much a "reserve" as a "|heads up your down to the bottom 1/4 of fuel"
    So the reserve fuel flows from the tank to the carb through the same tube. Normally.
    I can only guess as to the use of the capped off rear facing outlet.. May be for another model.
    Have you got a photo?
     
  11. thom wessels

    thom wessels New Member

    Dec 23, 2020
    5
    3
    Wildomar, CA
    I'll try to upload a pic. The petcock is definitely specific for this bike.

    Regarding 'reserve' function, I'm confused about your description. I get that gas will flow through a different tube from the tank when low, but the petcock has 'ON', 'PRI'(ME) and 'RES'(ERVE). My understanding was that when I got down to say 1/4 tank, I would need to actually turn the petcock knob to RES so the fuel would again flow. Otherwise, why is there a RES there?

    Thanks for any thoughts on this subject.

    Thom W
     
  12. thom wessels

    thom wessels New Member

    Dec 23, 2020
    5
    3
    Wildomar, CA
    I'll try to upload a pic. The petcock is definitely specific for this bike.

    Regarding 'reserve' function, I'm confused about your description. I get that gas will flow through a different tube from the tank when low, but the petcock has 'ON', 'PRI'(ME) and 'RES'(ERVE). My understanding was that when I got down to say 1/4 tank, I would need to actually turn the petcock knob to RES so the fuel would again flow. Otherwise, why is there a RES there?

    Thanks for any thoughts on this subject.

    Thom W
     
  13. Sprinter

    Sprinter Kinigit

    Aug 17, 2014
    6,026
    1,000
    uk
    Yes you manually turn the tap to reserve, it flows through the same pipe from tank to carb. Prime is only if you have disconnected the system ( does not need vacuum to flow).
     
  14. thom wessels

    thom wessels New Member

    Dec 23, 2020
    5
    3
    Wildomar, CA
    #14 thom wessels, Dec 31, 2020
    Last edited: Jan 1, 2021
    Got it. I do still wonder why they put the (middle facing) other tube there!

    (I see that the petcock tube that is being used actually faces rearward).

    Thom W
     
  15. thom wessels

    thom wessels New Member

    Dec 23, 2020
    5
    3
    Wildomar, CA
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  16. capt

    capt Elite Member

    May 8, 2016
    3,052
    750
    western Australia
    Looking @ your pictures.
    You don't have the genuine for Triumph fuel tap!
    Genuine has vacuum coming into the rear and Two fuel out lines/Connections. Front facing is the main line, this has fuel flow through when tap is in the On or Reserve position. The Rear facing Connection is PRIME !! It goes to right hand side of Central Carburettor down low..
    That tap looks like one off a Suzuki Bandit 600/1200 they have the same mountings to the fuel tank !
    How do I know this .... I'm researching a cheaper price for a tap for my T300 Sprint Executive 1998 !
     
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  17. thom wessels

    thom wessels New Member

    Dec 23, 2020
    5
    3
    Wildomar, CA
    That's weird because I bought the first one from 'Douglas Triumph', the dealership in San Bernardino. There didn't appear to be any question that this is the correct Trophy petcock. It exactly matched the OEM one that had never been changed out. Before I purchased that one I did a lot of research and it always came down to this exact unit. Second one was from a shop in Placentia that all the Triumph riders frequent and give very high marks to. What are you saying the actual 1996 Trophy 900 petcock looks like? Is there a website I can go to?

    Thom W
     
  18. Sprinter

    Sprinter Kinigit

    Aug 17, 2014
    6,026
    1,000
    uk
    The chances of two new petcocks being broken are very low. Keep going we are here to help.
     
  19. thom wessels

    thom wessels New Member

    Dec 23, 2020
    5
    3
    Wildomar, CA
    #20 thom wessels, Jan 1, 2021
    Last edited: Jan 1, 2021
    Thanks for the encouragement. The first new one went bad because apparently, the first shop soaked the tank (with petcock attached) in something caustic that ruined it's rubber diaphragm. I got a new diaphragm kit that time. The last shop installed the next new one because in the process of messing with it, one of the two little nubs behind the plastic knob was found to be broken off, rendering THAT petcock barely turnable. (I guess that means I've bought 2 .5 petcocks).

    The last attached pic above shows the suction tube was kinked off after I worked on the system. I added a short piece of hose outside of that tube to stiffen it and help keep it from kinking. It now appears to keep running. HALLELUJAH!

    I'm still wondering about 'reserve' function but I guess I'll just have to monitor the fuel level, see if it runs out at about 1/4 and go from there.

    Here's to carefree riding, all!

    Thom
     
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