My old 250E keeps loosing prime... after i prime the carb and run it awhile it starts fine but after letting it set say an hour... I have to prime the carb again.... anyone know what might be causing this to happen? it has done this every since i got it...

 

something in tank clogging screens?

 

possibly... but it runs fine once i get it started and has good top end, but it doesnt like to idle at all....i have tried turning the fuel off when it sits but this doesnt help... i have tried adjusting the carb but the screws dont seem to have any affect on idle or performance... i'm stumped... could i be getting air somewhere? the bike sat up for 5 years until i got it. i cleaned the carb and it runs but it wont just start up... i changed the fuel hose that comes off the little pump (dry rotted), and it is pumping fuel out but not at a continuous rate. it pumps with every turn over of the engine ( is that because it isnt running at the regular rpms?) it has a bad bowl gasket.. could that be the culprit? last question... how do i check the screens? oh i tried using ether and spraying around the carb while it was running but it didnt rev up was told this was a good way to find air leaks... any help would be awesome.

 

if it ant thing like my lts unscrew petcock from fuel tank should be 2 screws holding it on be careful with gasket dont rip it. hard to say if that your problem but you need chk everything I would also pull apart the petcock might as well chk it all

 

thanks but no my petcock is stand alone (not attatched to the tank) but that does give me an idea i recently bought a universal petcock.... i may just replace it and see if it will work... i am going to replace the gaskets and all fuel lines to make sure that i am not getting air into the system... I have a sheet of gasket material so i can replace any gasket (cut it out myself) so ill give that a shot but if anyone has had this problem before and can save me some time trouble shooting i would greatly appreciate it!

 

thing is, it seems to me like the bowl should be full after i ride, so for some reason the fuel is somehow draining from the bowl which tells me that it is losing syphon.... that says that there is probably air entering the route somewhere.... question is how do you find where the air is entering the system? this is just a guess based on my limited knowledge of fluid dynamics... lol i cant even spell it... but i wonder if there is something in the carb that could let this happen i.e. something not seating right or a o-ring that isnt sealing as it should... these are places that i would really like to start first just to clear them from my mind as i go through this process... anyone know where all the o-rings are in this particular carb?

 

After it sits remove the drain screw from the bottom of the carb to see if there is fuel in it.
On my 86 LT 250r it is hard to start after is sits. I use the choke with the switch off. Kick it three times, then turn the switch on about 3/4 throtle and kick it hard. It starts,

 

My bike is electric start with a pull rope back up... Anyone got any idea why a carb with fuel in the bowl whould not blow fuel into the combustion chamber when the jets are clear?

 

Yes I knew that, My point was to try turning it over with the kill switch off and check the plug to see if it is wet. Check the compression, may need to adjust the vavles.

 

from what i read it seems like your getting air and its not sucking the fuel in somewhere since ur jets are clear did you check all the seals