Qet primary jets- anyone have a Rochester reference

[Howard Sterndrive]

1984 3.8L (MR185 V6)
I bought a reman carb off ebay from i5, and it has worked really well for a year now, except I doubt the primary jets are right. The plugs look charcoal bbq'd after a long cruise at 3200 rpm.

the original rochester number for my carb is 17082515
anyone know how to find out what size jetting would be in that?

I'm kind of glad it was rich as my engine was new last year and I'd rather be rich than lean, but not this rich.

 

[Don S]

Re: Qet primary jets- anyone have a Rochester reference

.066, but here is a link to download the OEM manual. Section 5D covers the Q-Jet.

http://www.4shared.com/office/OWg8q3NF/07__GM_V6_83-93.html?

 

[Howard Sterndrive]

Re: Qet primary jets- anyone have a Rochester reference

awesome - thanks Don - I have the right rods (although 1 was bent), but .071 jets...

should be an easy fix... we'll see now if fuel economy improves. I was watching my mpg gauge pretty closely last trip out.
4.5 mpg was the absolute best I could get on cruise.

this video made it a breeze btw for anyone jetting a QJet:
http://www.youtube.com/watch?v=4BU7FfDXXi8

 

[Howard Sterndrive]

Re: Qet primary jets- anyone have a Rochester reference

hmm... secondary rods are way too big too... DA in it instead of DH
I have some DR's in another parts carb- very close to the DH
so I was running rich primary and lean secondary
I bet there's some unrealized top end in this scow.
.... I'm starting to think i5 just throws anything together that's on the bench

the assembly quality looks decent, but the parts are not right. going to check float setup too just for giggles.

 

[Howard Sterndrive]

Re: Qet primary jets- anyone have a Rochester reference

update....
big difference. Went from a max of 4.5 mpg to as high as 5.4 mpg
I don't smell gas anymore after shutdown.
Starts easier, idles smoother.
WOT speed is the same though - I guess the old secondaries weren't leaving any HP on the table after all.
For some reason the engine seems much quieter too from cruise rpm right up to WOT- can't figure that one out.