weird start up problem

[cbcanada]

this is obviously not gs related but i am stupmed and could use fresh advice..

i have an old yamaha 1981 xj750

bike was running, and i decided to clean the carbs

i sprayed seafoam diect into fuel line until bike would run no more

i put fresh tank of gas and tried to start wouldnt start. looked at plugs they were soaked with seafoam and fouled

i changed the plugs from bp7es to bpr7es (ic ouldnt find bp7es) and i snipped 1/8" off the plug wires because the contacts were bad and rescrewed them and confirmed spark in all 4 plugs

i went to start the bike and noticed gas pissing out from my air box over flow hose.

took the carbs back out and saw that i set the floats upside down, so i turned them over, put the carbs back on.. no more gas pissing from air box hose, i was happy !

try and start the bike, nothing,,, i pull the plugs and all are dry and look brand new, there is no gas getting to the cylinder? there is no sign of combustion

unfortunately i cannot use the drain screw to see if there is gas in the bowls because they are stripped. i did pull the gas line off the petcock and confirmed gas comes out at prime setting.

so what do you think has happened here guys? i dont mind pulling th carbs again but before i do this i would like to know what could have gone wrong here so i know what to look for.

[craigs449]

Sounds like no fuel getting from the carbs to the comb chamber.  Sounds like the floats are closing the fule supply to the bowls.  Did you confirm spark?

[cbcanada]

Sounds like no fuel getting from the carbs to the comb chamber.  Sounds like the floats are closing the fule supply to the bowls.  Did you confirm spark?

i did confirm spark on all 4 plugs! the thing is all four plugs look brand new there is no sign of combustion... so i agree no fuel getting in there cuz atleast they would be wet of gas.

so now here is what i am thinking. the frist time i set the floats the gas was pissing out of the air box drain hose, i pulled the carbs back out and figured the floats were upside down and flipped them over, i must have done something wrong and not there is no gas ccoming in there. i cannot confirm without pulling them back out but before i do i want to get as much info as i can

[craigs449]

LOL.......How the hell did you put the floats in upside down?  Find out what the correct float height is, put them in the right way, adjust them accordingly, and button it up.

[cbcanada]

LOL.......How the hell did you put the floats in upside down?  Find out what the correct float height is, put them in the right way, adjust them accordingly, and button it up.

this was my first carb cleaning... you know the parts that are suposed to float i had them turned upside down... i never touched the height of the floats so they should be fine as i said the bike was runing fine before

[craigs449]

The floats will and do go out of spec (heightwise) over time especially if sitting over a period of time in gasoline. 

[cbcanada]

The floats will and do go out of spec (heightwise) over time especially if sitting over a period of time in gasoline.

yes but 3 days ago before i pulled the carbs cleaned and put back together everything was fine...

[craigs449]

OK, well apparently all is not fine now.......Pull the carbs and check that the floats are installed correctly and set the float height according to specs for the bike.