Triumphrat

trophyste · 05-07-2009, 02:41 PM

hi guys im new so be gentle

i have a 1997 immaculate triumph trophy 900 but im having a few issues with fuel.

first question is on top of the tripple carbs is a rubber over two of my carbs breathers on the 3rd right hand side as you sit on the bike one is missing is this delibrate or should there be one on there?

second question

if i put my fuel tap to the on or reserve setting after a while it starts to starve of fuel if i put it to prime it last longer but eventually it will stutter also more so if i ride it eventually it will cut out.

i have checked for kinks there dosn`t seem to be any i have a pipe comming from the right hand side of the 3rd carb which goes to the centre of the fuel tap im guessing this is correct.

then one pipe to the right of the fuel tap the straighter pipe and one to the left of the tap with the curve on it im also guessing they are correct.

when the fuel gets to the bike it runs great.

there dosn`t seem to be any other pipes attached to the carbs other than the ones mentioned above, i read in the book there suppose to be two is this correct?

any help will be appreciated thanks

TxGr8WHite · 05-08-2009, 04:21 AM

Had the same problem on my 1995 Sprint 900. The fuel petcock has a vacuum line on the back (small rubber line) that allows the fuel to flow based on the carbs requirements. What happened to mine was the rubber diaphram in the petcock failed and I experienced the exact symptoms you described. Replaced the whole assembly (about $95) and everything works like it did on day-one.
Good luck.

narrowminded · 05-08-2009, 08:19 AM

While the tank is off, replace the fuel and vacuum lines. Triumph offers a rebuild kit for the petcock or get a new one, either stock or aftermarket. The tricky line is the vacuum tube from the carb to the center-back of the petcock. Make sure it doesn't kink.
WHile in there replace the fuel line filters, ensure the vent tube is ok.

Carry on!

jimballard · 05-08-2009, 09:43 AM

Don't forget to check the "tip over valve" by opening the gas cap a bit and riding the bike. If it runs o.k. with the cap doing the venting for the tank, then the check valve in the breather line (if you still have one on it) is probably clogged.

Hope this helps: Jim

trophyste · 05-08-2009, 10:09 AM

thanks guys looks like it is the petrol tap.

but i am curious about the carb vent a tiny rubber cap on top of all the carbs except the 3rd one is it missing or is it suppose to be like that thanks again

BlueTrophy · 05-08-2009, 10:51 AM

Where is that vac. line that goes to the petcock attached to the carb? On mine it is on that nipple on the carb.
None of those should be open.

trophyste · 05-08-2009, 11:37 AM

the centre of the petrol tap to the right hand side of the carb then on the top of the carb theres a rubber cap missing of the right hand carb as you sit on the bike.

BlueTrophy · 05-08-2009, 06:33 PM

The rubber cap missing is your problem. You should be able to get one at an auto parts store. I just replaced one on mine from Bike Bandit but I was ordering other stuff anyway. The 900 must be different. All the 1200's I know of use one of those to activate the fuel tap. Are they Mikuni carbs?

DCM · 05-09-2009, 06:00 AM

I have a 2001 900 Trophy that had a similar problem. The center carb should connect to the vacume line on the fuel petcock. When you replace the fuel lines use a few inches extra so the bends wont be a problem. Also check the large plastic selector knob on the petcock. Mine was broken on the backside. I filled in the spaces around the metal shaft with epoxy and filed the edges to accept the shaft. Once I got the fuel problem solved I ended up replacing the coils. 125% difference! Does not even sound like the same bike! Good luck with your bike!

NCBIKER · 05-15-2009, 11:09 PM

I agree. The missing vacuum line sounds like the problem.