80 Trailfire 340 carb question

[juiced71]

Hello Everybody...
I have a 340 trailfire got it for 200 bucks looks like the guy before me put a carb on it at some point in time because I have a extra one that came with it ...
its a mikuni ...
the only way I can get a decent idle is with the air screw all the way in and 1/2 turn out ..
had it out the other night ,throttle response isn't that great at low speeds but really hauls ass after it rolls out say about 20 feet out ..
pulls pretty hard mid and top end.....

rode it for a few hours ran good other then that... But at the end of the night I was cruising home and it died out ...
pulled it a few times nothing , put the choke on it fired back up and ran for about a 1/4 mile..
same thing , put the choke on started and shut off, buddy said open the throttle all the way ,I did that and it started back up ran for a 1/4 mile and died
,opened throttle all the way and fired back up ,made it home sheeeeeewwww!!!!
now I did notice today ,when I was poking around the fuel hose at the carb I touched it and it was loose at the fitting and leaked when I touched it ,maybe it was moving around sucked air? I know its a problem and I am gona fix that , now im nervous it will break down on next flight ...
thanks in advance......

[JDT]

If you do not know the history of the engine changing out the crankseals is a wise thing to do before your next ride.

[juiced71]

engine runs good other than it being a little boggy at bottom..
why you say change the crank shaft seals?

[harleysportster]

why you say change the crank shaft seals?

The crankseals seal the crankcase from the outside atmosphere allowing the proper transfer of fuel from the carb to the transfer ports of the ylinder. Bad seals means no or very little transfer, which means lean fuel mixture, which causes a melt-down.

[JDSnopro]

Listen to Harley. Bad crankseals give exactly the issue you are dealing with. If one or both are leaking, the engine looses crank compression and the engine needs to rev up to work. The most common problem with old snowmobile engines.

[juiced71]

Listen to Harley. Bad crankseals give exactly the issue you are dealing with. If one or both are leaking, the engine looses crank compression and the engine needs to rev up to work. The most common problem with old snowmobile engines.

not that I don't believe him I just don't know much about them ..
plugs look good tho

[harleysportster]

Refer to any 2 stroke service manual for an explanation of how a 2 stroke engine works.

[juiced71]

update...
clogged fuel filter...