Mike C Posted August 6, 2006 Share Posted August 6, 2006 I've finally started to fine tune my Del'Lortos. I havd Des Hamill's book and it shows 140 as a main jet for a motor with about 480cc per cylinder which is perfect for my mild 2.9l motor. But mine has 115 mains! Anybody else with Del'Lortos able to tell me what your motor setup and main jets are? The rest of my carb setup is right in line with what the book suggests. On a sie note, anybody run the Innovate Motorsports LM-1 wide band O2 air fuel ratio monitor and data logger? I think I'm going to suck it up and get one. $349 seems kinda' pricey, but if it does what it says it might be worth twice that! Quote Link to comment Share on other sites More sharing options...
Mike C Posted August 9, 2006 Author Share Posted August 9, 2006 I KNOW there are a few other guys running Del's. How about weber guys? What main jets are you running on your 40mm carbs and what sort of engine mods do you have? Quote Link to comment Share on other sites More sharing options...
Mike C Posted August 12, 2006 Author Share Posted August 12, 2006 Bueller...Bueller... Somebody help a guy out, please! Take 5 and pull a main from your 40 Del'lorto and save me some $$$$$! Quote Link to comment Share on other sites More sharing options...
Sam280Z Posted August 12, 2006 Share Posted August 12, 2006 You need to know more than just the main size. The choke (or main venturi) , auxiliary venturi, and air corrector jet sizes all influence the correct main size. The Delorto is very similar to the Webers DCOE and Mikuni PHH. Any reading you can do on these will help. A smaller venturi will create a stronger vacuum signal and require a smaller main. A smaller air corrector jet will let you run a smaller main and lowers the engine speed at which the main circuit comes on. There are some very good discussions on tuning DCOE style carbs on the LM1 forums. User type26owner has some interesting insights that allowed me to get my Mikunis running pretty good. I'm no expert and I still have a ways to go getting my engine tuned right, but you should check out the LM1 forums... http://www.innovatemotorsports.com/forums/showthread.php?t=3476&highlight=weber Quote Link to comment Share on other sites More sharing options...
Mike C Posted August 13, 2006 Author Share Posted August 13, 2006 I've done quite a bit of reading on the carbs. All of my other components appear to be just where they need to be, but the 115 main seems way out of line. I did not pull the chokes when I rebuilt the carbs, but I probably should of. I have a 45 accelerator pump jet 7850.1 idle jet holder 45 idle jet 7772.6 emulsion tube and the 115 main. All of these are appropriate for a 2.8l motor EXCEPT the main. I just want to get in the ball park when I buy jets. Guess I'll get the LM1 first. Thanks for the response! Quote Link to comment Share on other sites More sharing options...
ezzzzzzz Posted August 14, 2006 Share Posted August 14, 2006 You can pull a choke with the carb installed. Remove the air filter housing. Loosen the jam nut on the side of the barrel (it's at approximately 5 and 7 o'clock depending on which barrel you're pulling from. Back the lock bolt out of the barrel. Pull the choke out. The size is cast into the throat of the choke. There's a guy named Alfa1750(?) on eBay. I've gotten many parts from him. I'm sending a set of DHLA's over for complete repair and calibration. Once they're back I'll decide whether to run them or sell them. I love the look and sound of triples but my Ztherapy SU's kick arse too. Quote Link to comment Share on other sites More sharing options...
Sam280Z Posted August 14, 2006 Share Posted August 14, 2006 I have done a lot of reading on carbs as well. The stuff that type26owner has to say goes against alot of what I have read, but trying them brought me some better results. FWIW, Sam Quote Link to comment Share on other sites More sharing options...
Mike C Posted August 15, 2006 Author Share Posted August 15, 2006 Mine are 100% better than when I got them. They were on a friend's car he bought in about '88 and drove daily til around '99. I bought car in '03. I pulled the carbs and drained them. Then re-installed on same motor when I put it in my car. Ran like crap. Pulled and cleaned carbs and it was better. Ordered rebuild kits, completely disassembled carbs (except for chokes... reading about stuck chokes and pullers etc. had me shying away.) Much better now. In reading the Weber sticky, it may be my idle jet is too small? Still think I'll get the LM-1 first then throw money at jets. YOu could pay for the LM-1 in no time just getting several jet sets! Quote Link to comment Share on other sites More sharing options...
Sam280Z Posted August 15, 2006 Share Posted August 15, 2006 I agree. Get the LM1 first. I used one and it helped a lot. Sam Quote Link to comment Share on other sites More sharing options...
Rebird Posted September 12, 2006 Share Posted September 12, 2006 hey mike c, how is the tuning going? i'm about to do a triple delorto setup and was wondering how easy/hard the tuning went? thanks Quote Link to comment Share on other sites More sharing options...
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