carburator help

[motoman14]

hey, i have a 70's argo 6x6 with a kohler 2 stroke motor (k399 2t) and a tillotson hr4 carburator, and i cannot get the carb tuned right. when i rev it up gas/air mix comes out of the top of the carb. it acts like there it geting to much gas because it bogs out pretty easy, or its not getting enough gas, (like there is a back pressure from motor kinda explains the gas coming out of carb).it does run, but you have to play with the throttle to get it to rev up, ive tryed playing with the 2 adjusting screws, and the tab that is on the needle. nothing is seeming to help. the carb does have a fresh rebuild kit. has anyone delt with this before or has any ideas. thank you

[Slimpickin]

From my snowmobile racing days I would say you have internal motor problems. You shouldn't have any air gas mixture blowning back out the carb if things are right inside the engine. I've never worked on a two cycle kohler, but they all work on the same principle.

Slim

[jpswift1]

Another thing you should do is ditch the Tillotson carb ASAP and replace it with a Mikuni. Those Tillotsons and Walboros are not very good carbs and are very temperamental.

[motoman14]

ya, swift ive noticed that they have a mind of there own. where could i get my hands on a mukuni if i went that route. and slimpickin any ideas on where to even start?? thanks

[6X6]

Motoman, that motor is a piston port motor. Since it does not use a reed valve or rotary valve, the airflow DOES change directions, and without the air filter it can be noticeable. This is why they are less efficient/powerful as reed or Rotary engines, but more simple. You said out the TOP, is it coming out the intake of the carb or elsewhere? You should start a Tilly HR at 1 1/4 turns out.
Anyone looking to rid themselves of pumper carbs, I'll gladly take em off your hands. Yes, pure performance I prefer Mikuni, but for riding I like the twist a screwdriver adjust-ability. If you rebuild one and don't rush it, and run a filter, IMO you should get good service from one, but this is of course based on my experiences.

*Not typical. Your results may vary.

[motoman14]

ok. ya its coming out of the top of the carb. like the intake. It currenly does not have an air filter. you can visualy see it, and when you put you hand over it, your hand has a wet spot from the air gas mix. it dosent happen when its at an idle only when you rev it. thanks