# Dellorto Jet settings



## 2L Bunny (Aug 15, 2000)

Anyone here running Dell's. Let's share some jet settings to get a general idea of what works on what motor.
2L 8V, TSR head, 285 cam
Dellorto DHLA(h) 40's
37mm chokes
58 idle jets (jet holders are fixed in the h carbs)
.7 Emulsion tubes ( can't locate .5's anywhere)
150 main jets 
200 Air Corrector's
40 Pump jets

Runs like crap. I can get it to idle ok, but I think my pump jets are too small, and it won't accel past 3000 when under load. Standing rev it'll rev up. Too small mains?


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## PA 16v (Nov 5, 2001)

*Re: Dellorto Jet settings (2L Bunny)*

Accelerator pump jets only serve to compensate for lack of fuel between the end of the progression phase and until the mains can supply enough fuel when the butterflies are opened very rapidly.
I therefore do not think that it's the pump jets. I am more conserned with your 37mm chokes on 40mm carbs... Thats not much choking. I'd go with 34's. In fact, I didn't know you could have up to 37mm in a 40mm carb... Are you sure of your numbers?
I'd also bump the mains up by 10.
Carbs are fun aren't they


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## 2L Bunny (Aug 15, 2000)

*Re: Dellorto Jet settings (PA 16v)*

Yup, they sure are 37's, I bought them from Eurocarb, as the largest I could find stateside were 34's. From all the reading I've done the 34's seemed like they'd choke off my top end quite a bit. 
I'm thinking pump jets, as initial throttle tip in cause a hickup, but slow opening works ok. Similar to my accel enrichment on my SDS being tuned too low. 
I've ordered another step larger mains, as well as 180 a/c's as I was recommended them as well. Thanks for any help you can offer.


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## PA 16v (Nov 5, 2001)

*Re: Dellorto Jet settings (2L Bunny)*

Personally, i'd only put 34's in a 40mm carbs, especially since you have an 8v and you won't be reving close to 8000 any day soon.
The emultion tubes are probably way too rich, and since .5's aren't available any more (except used), I would gladly go two steps down to .14's. I think that's what is the real problem behind it all.
So, slightly bigger mains (160 or 165), leaner emultion tubes (.14) and 34mm chokes to draw the fuel properly from the tubes. And make sure your timing is advanced quite a bit (like 30 degrees).


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## 2L Bunny (Aug 15, 2000)

*Re: Dellorto Jet settings (PA 16v)*


_Quote, originally posted by *PA 16v* »_Personally, i'd only put 34's in a 40mm carbs, especially since you have an 8v and you won't be reving close to 8000 any day soon.
The emultion tubes are probably way too rich, and since .5's aren't available any more (except used), I would gladly go two steps down to .14's. I think that's what is the real problem behind it all.
So, slightly bigger mains (160 or 165), leaner emultion tubes (.14) and 34mm chokes to draw the fuel properly from the tubes. And make sure your timing is advanced quite a bit (like 30 degrees).

Glad to have someone here willing to help out, as most people on here just seem to repeat what others have said. That said








My 8V actually does rev up to ~7500, with occational overrev on track to 7800 with my old SDS. Again, quoting books, it seems that the 34mm's would be limiting my max RPM down to ~5500ish. 
The emullsion tubes are one thing that confuses me. My understanding with Dell's was that they are rich to lean on direct numerical order. And .5's seem to be what was recommended for 500cc cylinder capacity. I also have a set of .8's and .12(I think) if any of those would be a better idea.
thanks again,


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## PA 16v (Nov 5, 2001)

*Re: Dellorto Jet settings (2L Bunny)*

I wouldn't fear the 34's. Sure it will top out at 6200rpm, but now you can't even get past 3000! If you still have them, put them in and take it for a spin just to check.
Dellorto emulsion tubes are not from lean to rich in numerical order (go figure):
First, 7772.3 and 7772.4 are for DHLB32/35 carbs, they fit in DHLA, but forget about it!
Second, 7772.8 to 7772.16 are for emission control carbs... read on!
Third and last, general performance application, 7772.1, 7772.2, 7772.5, 7772.6, and 7772.7
Here is a list from lean to rich:
7772.10(e), 7772.8(e), 7772.2, 7772.1, 7772.14(e), 7772.5 (no longer sold), 7772.7 and 7772.6
(e) signifies the tubes are for Emission control carbs.
Although the 7772.14 is for an emission type unit, that is were it fits in the overall scheme of things. 
SO, your 7772.8's and 7772.12's would be too lean.
Theoretically, your 7772.7's should be ok... so what is your problem?!?
Put your 34mm chokes already!








What type of ignition do you run?


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## PA 16v (Nov 5, 2001)

*Re: Dellorto Jet settings (2L Bunny)*

I saw your pics in another thread, and I must say the carb bodies look to be bolted tight to the manifold, like it doesn't have a soft gasket to allow for the bodies to move.
That will make your fuel all foamy dude!







I hope you changed that!


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## 2L Bunny (Aug 15, 2000)

*Re: Dellorto Jet settings (PA 16v)*


_Quote, originally posted by *PA 16v* »_I saw your pics in another thread, and I must say the carb bodies look to be bolted tight to the manifold, like it doesn't have a soft gasket to allow for the bodies to move.
That will make your fuel all foamy dude!







I hope you changed that!


I'm in the process of changing that with damper kits in the mail. As to the 34's, now that I think of it I might only have 32's, I remember the included chokes as being rather small. And I'd rather not choke my engine to 6200 RPM's. This is a race car that will see street use maybe once every 2 weeks. The cam makes HP to right around 7000, with overrev above when I can't shift. I'd prefer to get them running with the right chokes for my powerband the first time even if it takes longer to tune.
thanks for all the help, Dell tech's are getting hard to find.


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## 2L Bunny (Aug 15, 2000)

*Re: Dellorto Jet settings (2L Bunny)*

Got confirmation that my dampers will be here tommorow, so I'll throw those on and see how they help. I changed jets a bunch tonight and made a HUGE difference. Also I checked and the chokes I had were only 30..ick
180 air correctors
165 mains
45 pump jets
I'm not sure if the 40's were too small or what? but they could also have been partially plugged as they were old. 
Results? Runs much better, I can drive it around, floor it at 2000, and rev it out. Now to work on the ignition side of it, then start the plug reading. Right now I'm running a recurved dizzy with vac advance of unknown origin. So I need to find out how much advance it's offering. If it's too much I may go back to a stock dizzy. Also chasing starting issues. With the car stored for the last 2 years ground coorosion to the rearmount battery could be an issue. Because the small sealed battery started it before on ITB's. 
I'll keep on working on it, and any other ideas would be appreciated. This is my first time working with carbs, besides my Go Ped


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## 2L Bunny (Aug 15, 2000)

*Re: Dellorto Jet settings (2L Bunny)*

Ok, for sake of searching for base settings here's where I'm at now and it seems to be running good.
Dellorto 40's 
37mm chokes
58 idle jets
45 pump jets
180 air corrector
160 main jets
*.8 emulsion tubes
The *.7's gave me an odd lean spit at highway speeds cruising. I was going to try the .8's as they have a leaner low end then run larger idle jets, but it's working great for now.


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