Newly acquired DT3  and the symptoms are as follows:     Put the choke lever down , kick the bike several times  ( usually starts on 2nd kick or so ) and the bike starts but will die if I open the throttle.  I have to just wait , as the engine barely runs around 1200 rpms.  I wait for 1 to 2 mins till the engine is a bit warmed and then I can take the choke off and the bike then performs nicely up and down the street with a steady idle .    Am I losing suction somewhere in my choke circuit ,? I've cleaned carb several times now and closely looked at the start jet at the bottom of the carb     Any thoughts from the group ?      Thank you in advance  Tom

One of us is wrong… my 72 RT2, up is enrichment… down is regular running…
Sneezles61

Lever down for enrichment & up for normal running. I'd still go back to the fixed jet in the bowl cavity & probe it from both directions--side on where fuel leads to the jet & from the top looking down & probe it to size if you can find something that size. Then flush it & blow it both ways. If it's not that, then maybe left crank seal needs changing. Don't have idle set too high as choke relies on a closed throttle to suck. Alternatively can only think fully dismantle carb--everything out & probe or at least eyeball all jets & airways. Idle mixture screw no further out than 1.5 turns or try one turn initially. Air leak that bad would be obvious. I'm out of ideas.

just talking about lever again, depending if ya talking the lever or looking at the plunger the lever lifts. I talk lever ya put your thumb on--push down for rich.

On my '72 DT2 lever up is regular running, lever down is enrichment. My bike also has the Mikuni VM26SH carb with the same #60 starter jet. I'd purchased a carb rebuild kit from Niche Cycles off eBay. One of the few parts that seem to work properly from the kit are those replaced in the choke.

On all the DT's I have or had lever down is choke and lever up is normal running.

Just to make sure I understand your question does your bike run normal when it is warmed up throttle response , rpm’s etc if so these are old bikes whether a Yamaha or Honda take several minutes to warm up. My Harley takes about  5 minutes to warm up

I was thinking the same thing... A couple of years ago I bought a 1971 Ford Ranchero "hot rod" that needs some work.

Brought me right back to what seems like yesterday... on a cold morning (where I lived in California it was fairly rare to get down to freezing temps so not exactly "cold" compared to other parts of the world) you needed to warm up your car before driving off.

Computers and fuel injection have really spoiled us.

Ht1kd  :   The bike performs well once I get through this warm up period.

Brzn:     So the rebuild kit you get from Niche cycle has parts for the enrichment circuit ?   I thought the enrichment jet
              was fixed in the float bowl and not able to removed ?  

I have the normal choke lever   down for choke  up for no choke
Also if it were a left side crank seal , wouldn't it idle poorly and not run too well ? 

Thanks for all your input ...

How warm is it outside when this is happening?