More on Basic Part - casting - Numbers

[makomark]

I have a marine Q-Jet with casting number 17090211.  Does the 9, fourth position, indicate 1990's build timeframe?

tnx

[jamesF]

I believe that 1990 was the last year a Qjet was used. So a 9 in that position makes sense as a 1989 designator.. ?

Just guessing..
Can you check the other casting numbers on the carb?

Click on the Logo up top and go to Cliff's site. He has some good info on numbers in the Tech Section. If you haven't already.

Good Luck!
James

[makomark]

James:

been to the tech articles pages and also have the book....the nine isn't covered in either spot, hence the Question.

tnx mark

[comp]

did you findyour info

[Cliff Ruggles]

Sorry I missed this thread.  Marine q-jets continued to use the early design castings thru the production runs.  I have yet to see a later style casting built by the factory as a Marine carburetor.  I have seen a few electric choke models, still based on the early castings, instead of divorced choke.

In any case, to date I haven't seen any q-jets, Marine or otherwise with a "9" in that location in the number sequence.   I would imagine that it is for a 1990 Marine application, as the last number run was "8" and coverted 1980 and later units.  It would make sense that a "9" would be the very next run, covering 1990 and later units. 

It would be interesting to know when the last Marine Q-jets were produced.  I've worked on a few Mercruiser marine carburetors as early as 1993, and they were the Webber AFB clones, not Quadrajets, so they may have been phased out by then?.......Cliff

[makomark]

Thanks for the responses.

I have a few service manuals and TSB-equivalents and will see what I can find. I concur with your timeframe and the transitional products. I do know they used a small, 2-bbl, MerCarb (that I was told was a rochester 2G knockoff) thru 1998 model year.

The V-8 service books split at 88-89 and 92-93. My guess is no more Q-Jets after 1992. that would infer no more production after 1991 (late 1990 on the early end,  early 1992, at the latest).

If more cast numbers show in the service pubs, I'll add them if there's any interest

[makomark]

Did some more checking in the service manuals.

found there were two small block versions that were made 1993 thru 1995 w/ a Qjet. one used a 17080565 casting and one used a 17085013 casting. In 1996, all production deliveries with Qjets had ceased.

[Cliff Ruggles]

Good information.  It appears that they used some Webber AFB clones when the Q-jets were first phased out, as we've encounted a couple of them.  Not sure how they worked out, as those carbs are the WORST carburetors I've ever worked on.  The accellerator pump is always defective, and they have no adjustment for the opening rate of the secondary airflap.  The owners of every one we've worked on complained of stumble/hesitation/bog when going quickly to full throttle.  Imagine trying the yank a couple of skiers out of the water and have the engine stumble!......Cliff

[makomark]

Sorry for being a bit slow on this but i think I've got the light bulb glowing now....

Marine Q-Jets, even the 170 series, are early (702 type) casting designs. This means they not only use the 'older' style floats but also the longer 703-style primary rods. So the mantra "don't use 70 series primary rods in a 170 series casting" doesn't apply to the 170 series marine Q-Jets?