Random / adhoc fuel starvation

Moderators: trixynut, Mincehead, dicky, phuk72, Jak, Kevtrx849

Post Reply
User avatar
drix
Site Sponsor
Posts: 555
Joined: Wed Apr 16, 2008 9:25 pm
Location: London/Surrey - UK & Valenciennes - FR

Random / adhoc fuel starvation

Post by drix » Tue Jun 19, 2012 3:43 pm

Hi all

Been having a bit of frustration with the Rex on what seems to be a random/adhoc fuel starvation and it has happened again today.

In short, yesterday, it was running just fine but this morn when starting up, no way she would idle (cold or warm) and so have to keep the throttle slightly open to keep her running (running rough by the way). Accelaration is fine although I can feel a little less pull than usual, there lots of farting about about from the exhaust on decelaration (already runs a little lean) and lots of farting about from the cylinder head breather when at low revs/light throttle. Fuel tap is on "on" mode, nothing changes if I put reserve or PRI, the fuel in the tank is fresh and the engine oil level is good. When I open the tank lock, there is pshhhh of air making me think the fuel doesn't go down properly but where to look?! Didn't touch anything over night, it was parked in the usual spot in the back garden, under the cover so I am little confused. :?

Had this problem randomly appear before and lifted the tank up, played with the hoses etc and the problem went away but it's obv a little annoying when it comes and not knowing what causes the issue. :(

By the way, my old tankhad two breathers and hoses to connect on the lower right side (when you sit on the bike) and the tank I have now only has one... this is the only difference I have noticed.

Any prompt help welcome as I am taking her to France Thursday eve :oops:

Thanks
Adrien

User avatar
cal
TRX-Enthusiast
Posts: 652
Joined: Wed Jul 28, 2010 11:46 pm
Location: York
Contact:

Re: Random / adhoc fuel starvation

Post by cal » Tue Jun 19, 2012 5:19 pm

There is a mesh filter attached to the fuel tap, that might want cleaning,tank off and drain job, then remove the tap from the tank.
there is another filter as the fuel pipe goes into the carbs, just at the point where the one pipe "T"'s off to the two seperate carb feeds again might need a clean.
Cal

User avatar
drix
Site Sponsor
Posts: 555
Joined: Wed Apr 16, 2008 9:25 pm
Location: London/Surrey - UK & Valenciennes - FR

Re: Random / adhoc fuel starvation

Post by drix » Tue Jun 19, 2012 5:28 pm

Phew, problem solved.

She was running on one pot as one header was getting warm whilst the other one wasn't on idle/low revs. This was due to a split carb inlet rubber... bought and cut some to fit the wider FCR inside diameter a few weeks ago but it obviously didn't like the work I did to it and its short life on a TRX engine :shock: .

Good idea about the mesh filter clean :wink:

Anyone got any ideas on the one tank breather hose instead of two and the pshh from the tank cap?

Cheers
Adrien

User avatar
Mincehead
TRX-Enthusiast
Posts: 6345
Joined: Sun Jan 25, 2009 1:40 pm
Location: West Sussex
Contact:

Re: Random / adhoc fuel starvation

Post by Mincehead » Tue Jun 19, 2012 5:37 pm

Really, did you get a tad carried away with the Dremmel or die grinder matching those internal diameters? :?
LOUD PIPES SAVE LIVES

User avatar
drix
Site Sponsor
Posts: 555
Joined: Wed Apr 16, 2008 9:25 pm
Location: London/Surrey - UK & Valenciennes - FR

Re: Random / adhoc fuel starvation

Post by drix » Tue Jun 19, 2012 11:51 pm

Mincehead wrote:Really, did you get a tad carried away with the Dremmel or die grinder matching those internal diameters? :?
Possibly :oops:

Thought what I'd done was ok and didn't think the rubber would split open horizontally :? I guess you learn from you rmistakes. One thing for sure is that I am becoming a pro at taking off and putting back on those FCRs! :lol:

cobbadiggabuddyblooo
Site Sponsor
Posts: 6809
Joined: Thu Aug 28, 2008 9:19 am
Location: Brisbane,Australia

Re: Random / adhoc fuel starvation

Post by cobbadiggabuddyblooo » Wed Jun 20, 2012 7:30 am

Run a piece of fine wire down the breather hose while attached to the tank (from the cap down)and make sure it's not blocked just to make sure
laughter is the best medicine

User avatar
Mincehead
TRX-Enthusiast
Posts: 6345
Joined: Sun Jan 25, 2009 1:40 pm
Location: West Sussex
Contact:

Re: Random / adhoc fuel starvation

Post by Mincehead » Wed Jun 20, 2012 5:34 pm

+1.

Use some 1mm stainless mig wire, it`ll bend around anything but remain rigid enough to find it`s way through, alternatively a blast from a high pressure air gun often clears anything. :wink:
LOUD PIPES SAVE LIVES

User avatar
drix
Site Sponsor
Posts: 555
Joined: Wed Apr 16, 2008 9:25 pm
Location: London/Surrey - UK & Valenciennes - FR

Re: Random / adhoc fuel starvation

Post by drix » Thu Jun 21, 2012 10:54 am

I'll sure give that a go! :wink:

Post Reply