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Tim Knowlton
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Joined: 03-17-2005
Location: Marblehead, Massachusetts USA
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This evening when I started my 74 1/5 I had to jump it with a power pack. Got it started and let it run for a good 20 minutes. Suddenley it just died I tried to start and had no response at all. No clicking of the fuel pump, turned the key and completley dead. Put a slow charge on battery for a few hours and still nothing. Pushed it into the garage and suddenley I heard the pump clinking and it turned right over. Moved a bit and died again then finally kicked over.. What's up with this????? 

Jim Sohl
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Joined: 03-26-2005
Location: Chandler, Arizona USA
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Similar things have happened to me over the years. As unlikely as it seems, remove, clean, and securely re-attach the battery post connections. Then see if symptoms go away.

Adam H
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Joined: 03-12-2005
Location: Poughkeepsie, New York USA
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I'd say most likely a loose ground.  The long shot that does happen is a shorted battery.  If you check your connections and they are all good then I would bring the battery to Auto Zone or Advance Auto to have the battery checked for free.

Mark Rosenbaum
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Location: Kingman, Arizona USA
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Most likely, it's just oxidation and/or corrosion on one or both battery posts and/or the mating surfaces of the battery cables.  If so, then cleaning as Jim and Adam suggest will cure the problem.  This is normally done with a metal bristle brush designed for the purpose, but sandpaper or a pocket knife will also do the job.  You'll want bright shiny metal on posts and clamps -- scratches, ridges, and gouges are all OK.

If you're particularly unlucky, the battery has an internal failure and will need to be replaced.  This is particularly likely if the battery has just gone off warranty -- something like two thirds of the auto batteries I've owned over the past ten years or so have died within ten days after the warranty expired.

Brett Gibson JH5 20497
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Tim, you recieved a good bunch of suggestions but if they dont work for you might want to try looking at fuse connections, I've been mucking about with installed Dellorto's and in the process brushed up against my in line fuses so the next time I went to start up I had nothing, no ignition light, zilch.

So I took them apart cleaned the connections and also added a very small washer into the fuse housing to give it more compression and that did the trick.

Tim Knowlton
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Location: Marblehead, Massachusetts USA
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Brett,

Thanks for the tip. Are you attending the 2005 meet?  If so let me know and maybe we can meet up in your neck of the woods and carravan.

Tim

Brett Gibson JH5 20497
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Location: Hilton, New York USA
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Yes Tim, I'll be there, ( if I can get these #%*^@+# Dellorto's sorted out ) I'm hooking up with Jeff and Laura Peterson from 2003 Nationals fame, and heading down there, your more than welcome to join up, the more the merrier, Jeff is putting the route together but it looks like something heading south from the NY Finger Lakes region ( nice twisty turny roads ), let us know if there's an intersecting point that works for you.

And Tim speaking of #%* Dellorto's are yours 40's and if so what kind of jetting and stuff are you using on them, for the life of me I'm having nothing but trouble with them, seem's I cant tune them in, no matter how much I balance and turn the mixture screw all they want to do is spit back, I've tried every tune up guide on the web from vac gauges on all barrel's to running on 2 cylinders at a time still Zilch,

Here's my data on them if someone should know of a fix for me, ( thank you )

choke  35        venturi   7848.1    main jet 130   MJ emulsion tube  7772.5     

MJ air correction jet  60    idle jet 55    IJ emulsion tube 7850.5  pump jet 45

cold start jet   70   CS emulsion tube  7482.1

the one thing I did notice is that on the drawings of the carbs posted the pump jet shows a spring in it and my carbs dont have that spring, not sure if it is cricital.

Any ideas

Thanks

Brett

Jim Ketcham
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Joined: 03-13-2005
Location: Salt Point, New York USA
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Hello Brett,

I went through the same issues with my first set of Dellorto's a few years ago.  For the stock 907 I strongly suggest using the jetting that Greg Fletcher recommended.  That is:

Venuris: 33mm
Main Emulsion Tube: 7772.5
Main Air Correction Jet: 190
Main Jet: 145
Pump Jet: 45
Idle jet 55
Starter (or cold start) Emulsion Tube: 7482.1
Starter (or cold start) jet: 70



I believe the smaller chokes are critical to get the air velocity up an low rpm.  I also used the same jetting on 45's and they work beautifully.  I think you will be delighted at the difference.

For the 2.2 stroker with 107 cams:

Venuris: 37mm
Main Emulsion Tube: 7772.8
Main Air Correction Jet: 230
Main Jet: 160
Pump Jet: 50
Idle Jet 58
Starter (or cold start) Emulsion Tube: 7482.1
Starter (or cold start) Jet: 70


Good luck,

Jim

Jensen Healey
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Joined: 03-11-2005
Location: San Anselmo, California USA
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Hi Brett,

Is your car stock? Eurocarb says the stock JH needs 33mm chokes.

The idle circuit is the most critical of all on the Dellorto carbs. The running up to 3000 rpm is facilitated by it. Your idle jets should be OK at 55 so the issue is probably the idle jet emulsion tubes. The 7850.5 is LEAN which causes the spitting back. I suggest you go to http://www.dellorto.com and purchase a set of 7850.7 idle jet emulsion tubes. This should get the car running.

If it runs too rich you can always drill out the correction holes to the next size. I actually soldered up my 7850.1 and re-drilled it until I got satisfactory results.

If there's a lack of power after about 3000 rpm you will need the main jets and air correctors as Jim Ketcham has posted.

Any performance modifications (or engine wear) will affect the tuning. When I install my 107 cams I plan to use the 35mm chokes (I currently run the 33s) and will have to re-jet.

Good luck,

Kurt

Brett Gibson JH5 20497
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Thanks for the tip's guy's, I guess I'll be buying some Dellorto parts today, I'll let you know how I make out once they arrive.

Brett.

Brett Gibson JH5 20497
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Kurt, I wasn't sure just what you meant by redrilling your emulsion tubes untill I just recieved the 7850.7 idle jet emulsion tubes from Dave Bean yesterday now I understand better , they are all the same stuff just differant size holes, I also recieved the Main Air Correction Jet's 190's which was a little strange because one had a differant size hole from the other 3, someone must have drilled it out and not stamped the size change on it, Dave Bean is replacing that one for me, Greg JHPS, is sending me the 33 chokes along with 145 main jets and hopefully that will straightnen things out, I should find out this weekend.

You mentioned that you were thinking of going to 35 chokes, which is what I will be removing from my 40's so if your interested in them let me know off line.

Also is there a chart or anything that tells what size holes are used on the differant jet's ???.

Thanks for the help

Cheers         Brett.

 

Jensen Healey
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Hi Brett,

I have never seen a chart but I did see a photo of all of them lined up. They are substantially different in the number and size of the holes.

Thanks for the offer but I have a set of 35mm chokes already.

 

Kurt



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