Crenche
Not a Newbie
Posts:15
Registered Users
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| 11/04/2007 10:41 PM |
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I will follow your instructions when I get the sea foam. There is Autozone up the street as well as Murrays discount auto. I will buy it there soon.
Is there a section on DIY for the Rochester carb yet? How to tweak and get it tuned up and running most efficiently.
I have no idea how to check how many jets my carb has on it. I think I need to rebuild it though.
I get a strong gasoline odor after I run my RV engine. I think it mostly due to bad exhaust manifold.
I thought I might as well rebuild the carb during this winter while the RV lies dormant.
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Airstream345
Site Host
Classic Master
Posts:1335
Administrators
Louisville, KY
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| 11/05/2007 7:35 AM |
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There is a great book on rebuilding the Rochester QJet. It's $13 on Amazon.
http://www.amazon.com/Rochester-Carb-Hp014-Doug-Roe/dp/0895863014/ref=pd_bbs_sr_2/102-3875540-1888965?ie=UTF8&s=books&qid=1194266129&sr=8-2
I bought it when I rebuilt mine. I also made sure to buy a rebuild kit from NAPA. A little more money but it uses higher quality gaskets and included a replacement float.
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Steven Webster
1986 Airstream Classic 345
Host, ThisOldRV.com |
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Crenche
Not a Newbie
Posts:15
Registered Users
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| 11/05/2007 9:20 AM |
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I will have to get that book when I redo the carb.
I hate to talk about other parts of the RV in sections that don't warrant it. For instance. We are talking about carbs in the generator section.
So was it easy to rebuild the carb? Never done it before but I would like to try.  |
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Jim Elliott
Camper
Posts:64
Registered Users
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| 11/05/2007 11:38 AM |
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The Rochester carb ain't easy to rebuild but is doable..Just take your time and MAKE sure you have the right REBUILD KIT.
Some of the better kits contain multible gaskets for the top, Study every hole in your old top gasket and match it up with the new.
A can of "Berryman B12" (spray) is excellant for cleaning out everthing inside the carb.
Idle adjustment screws not available for removal and cleaning out??????
Just turn the carb over and you will see 2 plugs up front along with 2 dimples on each side of the plug.
Once you see the dimples simply grind out between the dimples and 1/4 inch back from the plug and knock the plug out and now you will be able to adjust the idle mixture.
Grab the right slotted screwdriver that fits tightly into the main jet and remove the jets and see what you have.....My sold 87 had 76 jets and after a month of testing I settled on 73 jets which is the same as my current 83..............
I'll come back on the carb subject when the "Good book" is found with some other tips & part numbers.
Jim |
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Jim Elliott
Camper
Posts:64
Registered Users
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| 11/05/2007 11:45 AM |
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http://www.chevyhiperformance.com/tech/engines_drivetrain/induction_poweradders/0510ch_carburetor_tuning_gas_mileage/index.html
The above site can/will give everyone a greater insite to the Rochester carb.
Jim |
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Jim Elliott
Camper
Posts:64
Registered Users
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| 11/05/2007 12:20 PM |
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The Doug Roe book is a very good one
Also very good is the book by Cliff Ruggles (SA113)
Now for some interesting items IF you read the above site,
First of all you will need a "Indexed vacuum gauge"to find
out what your vacuum readings are while cruising down the slab,
They are indexed at 1 pound and work well.
Generally our rigs languish @60 MPH around 9-14 inches of
vacuum which is a waste of fuel with the stock carb that is
built for cars.....Why? Well the stock power piston
(power enriching rods) kick in at 11 inches of vacuum and below
so you can see we do nothing but constantly dump in fuel that's
NOT needed.
A power spring from GM (7037305) opens/pulls up the rods
at 6 inches of vacuum for enrichment and will save you a ton
of fuel, If you cannot find that spring a carb guru and I mean
a guru can modify your spring and dial it in.
Ignition timing for me is the start cuz once setup properly
your vacuum will automatically rise then it's off to the races
with the carb.
Ignitions should another thread and done first then lock it
down and forget about it..........
Jim |
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Airstream345
Site Host
Classic Master
Posts:1335
Administrators
Louisville, KY
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| 11/05/2007 7:12 PM |
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I split this topic from the original generator topic since it became more about the QJet.
Jim,
Great tips. I'm going to look for that spring. I've always felt like my rig runs too rich (especially since I installed headers and 2.5" exhaust) for it's own good. With few options for carb adjustments I like the idea of replacing that spring. |
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Steven Webster
1986 Airstream Classic 345
Host, ThisOldRV.com |
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Jim Elliott
Camper
Posts:64
Registered Users
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| 11/05/2007 8:53 PM |
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Steven, With headers and 2 1/2 inch plumbing that should have leaned it out a dab
so you can see just how overly rich they come from the factory.
Before you touch the carb I will open up the ignition section cuz by doing certain
mods it will get rid of some of the rich conditions also.
That poor carb gets more "bad mouthing" then it deserves and can be cured,
Those springs come in a 10 pack and like I said a true GURU can cut them down
to keep the rods in place above 6 inches instead of 11 inches.
Jim
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jsteiner4
Newbie
Posts:6
Registered Users
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| 12/26/2007 5:43 PM |
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| I've rebuilt about a hundred Q-jets over the years as a dealer tech. [ 19 yrs. pre fuel injection ] including the one on my current '87 Southwind. What I've found in recent years is float saturation with composit floats. [I don't know if this is from ethenol fuel or just plain old age ] NAPA sells brass floats for under $15.00 and I would recommend that you pick one up with your carb kit. Don't forget to properly set the float level [ the instructions in most kits these days are sketchy at best, find and use a good service manual] and properly torque the float bowl cover to prevent internal vacuum leaks in the enrichment circuit. Take your time match all parts and gaskets and you'll do just fine. |
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73Krager
Not a Newbie
Posts:24
Registered Users
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| 01/31/2008 6:54 PM |
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Jim,
Quick question. I have a Rochester on my Chrysler 440. Do you think the spring would benifit my set-up? I am going through the ignition section and trying to see if it applies to my 440. Is anyone buying the big tenpack of springs? We could share costs. Also, looking at the diagrams, I think I can change the spring while the carb is installed. Is this advisable. The engine and carb are fairly new (2000 miles) and I don't want to upset any of the good work that the previous owner did.
Thanks,
Larry
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