I battled with two things during the major heat wave here. Fuel petcock did not have enough steady flow for sustained red line ''the rubber inerds warped'' and I had to place the the fuel line into a cooler spot. In the end with that carby I had taken the petcock out and ran the line straight back with a inline filter of coarse. The float was working fine.
What I always had was if I sustained a somber Idle for way too long without periodically bumping the throttle just had to raise it a little '' note did not have to rap it'' I had to go half a neighborhood block to blow the motor out. Then it ran great perfect!
The Morini has been a way different animal than a H.T. At 11,000 12,000 rpm as compared to a 6000 rpm motor. Think of a hot rod V8 motor with a lot of carb loading up from excessive Idling is the best description I got like when its at a mechanic shop and got moved and parked for a week and never blew out.
I am at 6000 feet above sea level I did just about absolutely everything with that original carb set up. I am convinced it was as good as it gets. Went three Atomizers leaner among trying jetting and it was not bad after that!
I spent a small fortune in jets etc and everything for these model Del's fits another Del! So I am ready for a custom bigger jug piston set later on and or to go to one of our bike races at a different altitude.
I love Del's now!!
6000 foot would be about roughly a 30% percent difference in Horse power from sea level so I hear and after studying jetting through other forums across the country the info reflects this percentage wise in jet sizing for every 1000 foot.
Also reading about Ultra Light planes you get this info too.
I got one of Nidyanazo's old carbs his was selling he kept from a custom Morini he sold. The Del 21mm I put on today. Thanks buddy! Now I know what he jetted that carby at at sea level
I can't always say I know what I am doing. Always learning something new that's what I love about this hobby!!
The 21 is a improvement with the extra high elevation thin air here. Its kinda like a touch of porting just breaths much better. It is essentially the exact same carb just a larger opening at the intake side. The kinda feel you get when you port out a china 2 smoke kinda thing for the first time. I pack more into the motor now. Plus since I used the original custom jets I should in theory get a tad better gas mileage. lol.