Urgent help needed.

[ATC185guy]

Ok, so I bought my 81 honda atc185, blew the motor in about a month, it needed rebuild bad when i bought it anway...well then i bought 2 whole motors, threw one on....no spark. threw the other one on, started first pull...I rode it for about 5 minutes then it started bogging down when you hit the throttle, it would idle just fine....well so i rebuilt my carb, it did the same thing ran great for 5 minutes after warmup then started doing the same thing...so i thought, must be a junk carb. so i buy a new one off ebay....throw it on...adjust idle...ran great for 5 minutes then it would just die every time i hit the throttle...it has me completely stumped...ive got over 500$ into this thing and it just isnt running right. ...idk if maybe the timing is off...if that could do it, i dont know. the plug is fine. could the spark plug make it do that? Really thats all i can think of, i have a top end rebuild kit but i dont think the new motor needs to be rebuilt, it was used but clean as hell and in mint condition. i just dont know...
please help.

[jeffatc250r]

Sounds to me like a plugged gas tank vent. try cracking the cap and see what it does when it starts running poorly.

[ATC185guy]

thats what i was thinking, or possibly ther fuel filter....but everyone at my friends house where im storing it, they all ride and they said that cant be it but idk...im gonna take the petcock out and check the filter and see if the gascap vent is clogged...but im open to more suggestions, iwant allot of things to try tomarrow when i go over there lol..sorry about the poor punctuation, i spilled coffee on my keyboard and its sticky.

[Walkerallen]

my 110 had the same problem, first check the petcock screen, if that dont fix it check the timing

[Mr_RPM]

maybe electrical? the fuel problem sounds like thats it to me, but alot of electrical parts dont work properly when they get hot, maybe you have a faulty ignition coil or CDI once the engine gets them hot.