case 30x4 stalls when under load

[henretty]

Maybe someone can assist me? I have an older case 30x4 with a 30 hp wisconsin motor. (4 cyl) while sitting and idling runs fine, but at full throttle and operating trencher or hoe or even driving, it wants to stall. and by pulling choke it will rev back up. have replaced fuel line, replaced air filter and cleaned all associated hoses etc. any suggestions on what may cause this frustrating situation..

 

[henretty]

ok so after checking spark...(good) I was doing more looking and noticed a small amount of condensation gathering on manifold right above mounting bolt head..hmmm small leak causing too much air into manifold which would explain why using choke would stop stalling??? any ideas on if this is the case? if so any ideas on fixing the leak after locating it?