yesterday afternoon was a typical yuma fall day, sunny 85*, debby and i went out to run errands on the bikes, when we got to the stop sign at the highway(aprox 1mi) her bike died when she clutched in to idle down (hmmm, thats  odd, i thought to myself) ???. when she restarted, it took a few cranks, normally it pops right off (hmmm, thats odd) ???, when it lit off, a boil of  black smoke exited the tailpipe (hmmm, thats odd) ???. so we decided to go on down the road and see if it would clear up. at the next stop light (aprox 2mi) she and the bike went through this drill all over again! at this point she is not having fun, and i'm not happy with a certain carburetor rather than fight her way through town and wrestle with this thing in city traffic, we opted to return the suzuki home, and would run our errands two-up on my HD.
 later in the afternoon (aprox 2hrs), i was done being mad at her bike, and decided to dig in to it, naturally the first thing is to fire it up, and diagnose the problem. it fired up and ran perfectly! so, go for a test ride, it rode and ran fine! ??? i'm starting to think i've got an intermittant issue with the needle and seat. any body else have similar issues or suggestions?

Sounds like it's running rich. Maybe dirt or a bad float?

I'd bet on reelthing's experience.

Check for fuel in the petc0ck's vacuum line.  There should be absolutely none.

Toss a shot glass of two stroke oil in every other tank full, can't hurt anything.

Serowbot wrote on 12/31/69 at 16:00:10:

no vacuum, 'nother idea i didn't like, so ours has been converted to manual.

georgekathe wrote on 12/31/69 at 16:00:10:

i,ve been dumping my extra 2stroke fuel into my cars and 4stroke bikes for 30+ years and never noticed the smoke in the exhaust like you get with the 2stroke motors ??? as mentioned you'll add lubrication to the fuel system, not nessesarily a bad thing. i used to add a cup of marvel mystery oil to 5gal of aviation gas, when i was running it in my sandbuggy, because av gas doesn't have any lubrication additives or properties.

Ed L. wrote on 12/31/69 at 16:00:10:

i might give that a try, we have a 2oz bottle of marvel mystery oil that we carry behind the chrome side cover, i think the tool kit is supposed to be there.

Savage_Rob wrote on 12/31/69 at 16:00:10:

does it fit in the stock air box and cyl mounts? i'd like to try to keep that stuff in place if possible, which is why i was considering other carbs from similar type installs.

I do add a little bit of 2-stroke every now and then - maybe 1 oz to every 4th or 5th full tank - but it's syn castrol tts - next to no smoke or carbon buildup at far higher mixtures - the idea is to add a little lube to the slide - the biggest deal I think on the slide galling - other than the design - is air leaks around the filter or the rubber intake boots - you can help the stock airfliter seal better with some grease on the foam - of course this 10%Eth doesn't help matters any either

thanks! i'll certainly keep lancer's amal in mind.