Hi all I have a TY and whe i first got it it was a bugger to start,anyway i fitted a O-rng kit off evilbay and the bik started better and seemed to run better,the float needle was prone to sticking but i have cleaned everything I could and it still was a bad starter but once warm was fine.it sat for a month with the carb drained and i cant start it now,it runs for a bit on the choke but won't run off choke,

have a good spark and wet fuel on plug so its getting through,any suggestions? is ther an sir screw position that is best? we've had the carb apart several times and it's got us stumped.

when i got the bike there was a tube thatwas connected to the choke side and ran under the carb and connnected to a fitment on the oter side? is that right as it looks in pictures that there are two seperate tubes one on each side as drains???? should they be connected by a single tube?

Silly question, but have you ever checked the points & timing?

 

With it running with choke and not without you'd best start with pilot jet.

If this is blocked it won't idle unless the choke is pulled on.

Unscrew the smaller brass jet and hold it up to the light, if you can't see a small round hole in the light, it's blocked.

 

Next check the oil feed union on the carb (small pipe stub right side of carb, forward of slide)

Originally they came fitted with an autolube system to supply two stroke oil to the engine without the need to premix, nearly all these days have had the pump removed and drive to the pump blocked up inside the front part of the right hand crank case cover.

This stub on the carb should, if the autolube system has been removed, be blanked/blocked up or it'll draw in air.

 

There should be two other, similar pipe connectors on the carb, one to balance the air in the float bowl and one to balance the air in the carb body, it's often normal to use the same tube looped around to each connector, but doing this it needs a hole or split in it somewhere to allow air to enter/exit.

 

If you're still having issues, hard to start, wet plug, bad running without choke and are sure the spark is timed correctly, I'd say you have an air leak somewhere.

This could be either the crankseals,  perished inlet manifold or it's gaskets or head/base gaskets.

ok the oil feed it blocked off the tube had a hole in it but i thought it was perished so i replaced it with a new pipe,i'll put a hole in it,pilot jet is not blocked.i haven't checked the timing,the inlet manifold looks good.Thanks for the replies,

it was a bugger to start but was fine when warm,maybe an air leak or gasket?

ok i left it for a couple of hours and it started and seemed to rev and settle but then wouldn't ,got all fluffy on the throttle and died so i think it's the carb and not the points/timing.as it got hotter i would have thought air leaks might have sealed a bit.

any further thoughts?

 

 

"There should be two other, similar pipe connectors on the carb, one to balance the air in the float bowl and one to balance the air in the carb body, it's often normal to use the same tube looped around to each connector, but doing this it needs a hole or split in it somewhere to allow air to enter/exit."

 

 

this is very useful, but leaves me with a question..

the tube that might be running from the throttle body to the float bowl, is it supposed to be 2 separate runs? vented to somewhere? On my bike, one line connected the two, but it looked half-assed so I assumed t was wrong.

right now they're both capped.

Edited October 5, 20169 yr by contiki

ok i left it for a couple of hours and it started and seemed to rev and settle but then wouldn't ,got all fluffy on the throttle and died so i think it's the carb and not the points/timing.as it got hotter i would have thought air leaks might have sealed a bit.

any further thoughts?

i'm guessing you've checked to see that the plug is gapped correctly, and that your fuel tap isn't filled with debris? It almost sounds starved for fuel once it's running. 

carb slide isn't all scraped up and grooved? air leaking in from that can cause trouble also. 

theff float needle was getting stuck open and peeing fuel from carb,clean it up, it might be getting stuck closed starving the float?

Edited October 6, 20169 yr by retromlc

ok all good nowstripped the carb and fond some debris underneath the float needle brass housing,unscrewed it and was muck in there,probably running the best it has now,Thanks for all the advice

Check the O ring seal located around the main jet area which fits into the float bowl, if this is a poor fit it causes many issues.

Check the O ring seal located around the main jet area which fits into the float bowl, if this is a poor fit it causes many issues.

it was replaced with o-ring kit,bike running well now

don't get rattled.

if the problem was trash in the float needle, it's possible that new trash has made it's way down from the tank and cheesed you again.

If it were me, I would pull the tank, slosh some clean fuel through it, flush out the tap, and maybe replace the fuel lines and filter. If everything upstream is clean and happy, you might be set.

you're going to have to check the carb again to see if it's the same issue as before.