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Engine won't start (first start)


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I'm restoring a 1930 Hupmobile S, as close to original as I can.  I've gone completely through the engine, new rings, gaskets, cylinders sleeved, etc.  It has an updraft carb on it, I bought new one that fit a JD tractor.

 

I have a spark to the plugs (I got quite the "shock" figuring that one out) :)

 

I'm getting fuel to the carb, running it gravity from the vacuum tank. 

 

The engine turns over well, I'm getting a good amount of suction on the air intake on the carb while its turning over.

 

After turning over the engine for a while, and choking the carb while doing so, I have taken a spark plug off and don't smell gasoline under the plug, only the Marvel Mystery Oil I have put in there.

 

Also, after turning over the engine for a while, and choking the carb while doing so, I get a couple teaspoons of fuel that pours out the air intake of the carb.

 

I have had it fire once, but only once, and there was a decent flame that came out of the exhaust with that one.

 

I'm at a loss for what I'm doing wrong here.  Any help from the hive would be much appreciated.

 

Eric Hupp

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I take it your car doesn't have fuel primer cups?  You mentioning that there is no smell or sign of gas makes me wonder if its not pulling the fuel up from the carb.  I guess a serious intake leak could cause that but I am not an expert.  You are on track, spark, and fuel at correct time and she should fire. Be sure to let us know what you eventually find is the problem.

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I’ve double checked timing, with #1 at TDC both intake and exhaust valves are closed.  I’ve also verified distributor is not 180 off.  I’m leaning towards the intake leak, but I don’t think I’d have the vacuum at the choke that I do if that were the case. 

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Sometimes the simple things confound the wise. Is the firing order correct ? I went through all this with my '25 Buick. Checked timing, distributor ,carb, etc. We cranked it, towed,it and pushed it, to no avail. After everything else failed, I read the manual. I assumed the firing order would be like all GMs I had encountered ,1-5-3-6-2-4. Nope.

This one is 1-4-2-6-3-5 ! It fired right up after switching the wires around.

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Displacement on the JD is 202 cu in compared to Hupmobile 210 cu in

 

i did find that I had it set up for CW rotation where it is actually CCW rotation.  I changed that, I’m hoping that will make all the difference!  Good idea!!

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Yes CW vs CCW will make a huge difference.  I run a small Carter BB1 on my 28 and 31 Graham both run great (1 1/4 inch throat).  Just a dumb question it should be 6V positive ground car... I would check to make sure the battery connections are correct.  Also if it is turning over too slow they don't like to fire.

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It should roll over pretty good, how do the battery cables look?  I just go down to the local tractor store and get a new set of 6v cables.  Most welding supply stores will make up cables should be 2/0 copper.  If the cable is not the is size of your thumb it is too small, need to check the ground cable also.

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6 hours ago, EDHupp said:

Yes, I have it as 6v positive ground.  Slow turnover is certainly a possibility.  Any thoughts on getting it to turn faster (besides putting a 12v battery on it)?

 

Should be more than adequate, it's worth checking that your strap doesn't have rust/crud built up where it bolts to the chassis 

 

Old engines will start pretty readily if they've got fuel, air, spark and timing. They might run like garbage until you get them dialed in but but it should at least show signs of starting

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My 1931 model S, when first started, needs the spark pulled out about 1” along with the choke all the way out & hit the starter.  After 5 or 10 seconds I push the choke in as I pump the throttle 2 or 3 times.  I pull the choke out & try again.

 

how is the compression?  All the cylinders should be about nearly the same about 70 or or so.

 

check the vacuum at the windshield wiper motor to see how close it is at the air intake.  My car has a rubber hose under the dash connecting 2 metal lines.  Ran better after I replaced it.

 

 

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