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

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

 

I'll look at that. I guess I could just leave the cap loose as a quick check.
Thanks
Thom W

 

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

 

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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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

 

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

 

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

 

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

 

[QUOTEtsuction tube.ube faces toward the middle, as does the ="Sprinter, post: 508074, member: 1940"]https://www.worldoftriumph.com/collections/304679-2-2?type=trophy-upto-vin-29155[/QUOTE]
Here (should be) a couple pix of the petcock. I made an error. The capped off petcock is on the back of the unit, as is the suction tube. The one that's used faces to the rear.

Thom

 

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

 

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