@Gordon Nichols posted:I found it very interesting that both Dave and Justin at Blackline Racing, the guys who rebuilt and set up my 40mm Dells, did NOT like Jet Doctors. I had them installed since the first days of running my Dells for all of the same reasons; they push the air inlet to the jet way up at the top off the air cleaner so “less dirt can find it’s way in”. That’s the story I believed.
Dave said he has seen a lot of problems with jet doctors and doesn’t recommend them for his clients (sorry, I can’t remember specifics). I had the original, shorter jet holders from when I first set up my Dells and sent them along with the carbs for their rebuild and Dave installed the originals, set everything up and sent them back. They’ve been running flawlessly ever since. I mean, I am amazed at the difference before and after rebuild.
Now, in the 18 years I had been running my Dells with the jet doctors, I had exactly one instance when I can point at something and say “that, there, is a clogged jet”, unclogged it and it got better.
Once.Other than that, they ran OK, just tended to lean out during transition off idle and I couldn’t cure it on my own.
I got my Dells back from rebuild around the end of last August and, so far, haven’t had a single issue with them, even with the shorter jet holders. And believe me, they’re running so well I’m not gonna touch them!
A friend of mine installed the Jet Doctors and noticed the car didn't run as good as when it didn't have them.