Challenge number 924!

We have 2 DT3s. One start easily one does not. 
Both have comparible compression
Both have new points.
Both have a good spark.
We have swapped out reeds and carbs.. ie works on one but not the other.
So is our conclusion we have a timing issue?

If so, apart from adjusting the gap... how do we adjust timing 

Any help welcome

if it's similar to my Dt1, then the guidance I got confirmation on from experts is that you set the timing and the points gap is what is is and if it is out of spec then time to replace points since cam follower block has worn out of spec.  You can probably find the manual in the tech library to confirm

good luck! 

Exactly.  You adjust the point gap to set the timing.  Then then max gap should be within acceptable range in manual. 

Ok ....time to eat some humble pie. After an hour fiddling, sorry..fine tuning the gap... still nothing. So when I said I swapped reeds, carb etc from them
 firing bike to non firing bike, the one thing I didn’t swap was .... the spark plug. Now, both bikes had a spark, I checked that. But when I replaced the new splug with the crappy old well used spark plug... it fired up... has done since. Probably circumstantial... but both bikes are now running. 

We've all been there.  I tend towards pulling out the engine and tearing it completely apart before realizing the reason it quit running was I ran out of gas.