Hellp me tune my carburetor...
 

I'm new here (again). I bought a Miata with an LS1 in it a few years ago but sold it before I really got to mess with it. I posted a couple of times but things didn't work out with the build (rebuild) so I dropped out. Well, I did it again. I bought a Miata with an automatic and 383 stroker in it out of Iowa. The car has a Holley 670 in it. I don't know who did the setup on this thing but it runs horrible. It idles ok but just doesn't have the smooth power that it should have. There is a dead spot and just bad performance in general. The only work I have done on it so far is to fix the bowl levels. The primary bowl was way too full and the secondary bowl adjustment was bottomed out with hardly any fuel in there.

So, I'm wondering if there are any guys in here who are good with carb setups that might be willing to give me some tips on where to start?

http://www.lightweightmiata.com/stroker/stroker02.JPG

Give me a call at the shop tomorrow. 843-225-1142

I spoke with Frank Defelice last night and he suggested calling you. Will do...

Get a bigger carb... 750 or 850 double pumper. The 670 you have is probably a vac secondary. I have a 750 dp I just took off a 383. I will take $150 for it and you can try it out first.

good call. :bigthumb:

I wouldn't go as big as a 850dp but a 750dp would be good.The 670 could be tuned in also,but would lose in the upper rpms.Vacuum secondary carbs take some work to get right.I have a 3310 750 vac sec I would get rid of also.I has been worked over with a secondary metering block instead of a meter plate.So,the secondary jet can be changed like the primaries.If the carb has a dead spot off idle,the acc pump needs adjustment or a larger squirter be added.First that should be done is set timing.Then adjust idle vacuum,metering block vacuum screws,with a vacuum gauge.After that is set then play with carb adjustments.The acc pump adjustment at WOT should be .015-.020 clearance.