Fuelling problem
 

Hi all,I've got a problem with my 43f XT600 and could do with some input..
I went for a ride on it yesterday,only got approx 10 miles and the bike hesitated when I went to roll the throttle on,say from less than 1/4 throttle to 1/2 throttle as if it was running out of fuel,I switched to reserve and it did it again,(there was plenty of fuel in the tank),I decided to head back home before the bike died but it died on me a few miles later,after about 15 mins I got it start again but once more it died before I got home and I had to push it a few miles:(.
I left it for a few hours then I checked the valve clearances,all ok.checked the plug and it was running weak (light grey colour), I then got it to fire up but once again it died after a few minutes.I have a in-line clear fuel filter on it and there was fuel up to this point,also fuel in the float bowl, when I got it to fire up again,after a few minutes it started to die but i found that if I gave it more choke it would run.So I reckon the problem fuel related not ignition.
I've now took the main carb apart but I ca'nt find anything blocked,pilot jet is clear.
I fitted new inlet manifold rubbers 500 miles ago so there's no leaks there,could the problem be float height,and if so how do you set it,the manual says I need a special tube,what do you all use?
Thanks Mark

Check the the rubbers on both sides of the carb, airfilter, airbox and such for leaks ect ect.

Perhaps a jet in the carb is partially blocked or something wack.

Sounds weird.

Hi , I have had the same problem last week, smae bike 43F which has been dry stored for about 5 years and started occasionally. Just got it mot the other week and noticed when riding at high revs it was missing and holding back when the throttle was open wide, Thursday in town it completely cut out, after 5 mins, managed to get it started but once i got back home the bike cut out again.
I first thought tha plup cap had broke down because when i pulled of the cap it fell to bits, replaced the cap and a new plug but still it wouldnt start. Today i decided to strip the carb and double check to jets, first thing i noticed was the RHS inlet rubber had started to go brittle, flake and brake away, once i removed the rubber you could pull it away slightly reveling light through it. I replaced it with a spare one from my TT600 and once it was back together it started first kick, ticked over nicely and went like stink, no missing or popping or banging. Noticed you have replaced the inlet rubbers but have you replaced the oring seal as well that sits behing the inlet rubbers. :mchappy:

Good luck
Mark

You don't need a special tool to check the float level.
You can measure it per manual specs, or you can just use a clear hose put in the secondary feed and run under the carb to the outside where you can see the gas level with it held up to the side of the carb.

I had YDIS issues that turned out to be a bad needle/seat. the little nipple had extended farther than it should it was next to impossible to adjust the float correctly.

Just sounds like fuel starvation. Dirt/water in fuel?
Check tank is venting OK - no shite in tank. Run a litre out the tap/fuel ine & see how long it takes & how well it flows. If slow, try with fuel filler cap off.

That fuel filter under the needle and seat
 

Hi all,
Have you checked that little filter under the needle and seat in the fuel :thumbup1:bowl.
Search this site for the thread.

Cheers from Oz.

Ken

That would be my first move.

Well it's running again
 

Hi all,just an update,I stripped the main carb down, took out the main & primary jets,took out the filter under the needle/seat,couldnt find any blockages so I blasted everything with carb cleaner then blew everything through with the air line.I then reassembled everything,gave it full choke and after a couple of kicks she fired up.At first the bike was running a bit rough but after a minute or so the motor cleared and the bike's running fine.I then put on pair of boots that are'nt so bad for pushing a bike in and went for a test run,I made a point of not going anywhere that would involve a uphill push but the bike was running great.:thumbup1: When I got back home I put a new plug in and did 20 miles on it with no problems (after the first journey the original plug looked less weak than when I was having problems).
Anyway a couple of questions;
1) The pipe between the main carb & secondary main jet had split so I replaced it with a piece of fuel line,the problem is this pipe is pre-formed and when I replaced it with ordinary fuel pipe it has to bend through 90 degrees to attach to the secondary carb.If the pipe has slightly kinked I can understand it affecting the fuel flow but wont that just be at the stage were the secondary carb opens and be irrelevant at start up and low revs?
2) I recently bought a locking filler cap,so if it's not venting properly I can understand that causing problems,but if the revs pick up when I give the motor choke does'nt that mean the carb is getting enough fuel,it's just not getting it in the pilot circuit?
Thanks for the advice
Mark

The secondary carb will have some effect on the idle, and could well effect idling, coz its open a little bit !

On the YDIS the secondary has a butterfly that is sealed airtight when closed and adjusted properly. :nono: Spray some carb cleaner in there the next time you have one off. It will not leak out. Evaporate yes, but not leak.

There is not idle circuit provisions to the secondary. There is a crossover that equalizes the vacuum between the primary and secondary.

Cheers Zecatfish..... I didn't imagine it would be 100% air tight when shut.... ?

But thanks for the tip, new one on me this type... The old CV's were never air tight even when fully shut.