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302 Pops and trys to die at top end ( was "newly overhauled 302 won't start".)

Back to post #59 (too late to edit)....

To clarify in paragraph 2: "if fuel bowl is draing empty while sitting for an extended period of time...."

I mean to say overnight or just a few days. Later in paragraph 4 I clarify the timeline better.
 
I dug into my archives:
'74 & '77 302 170/175/190/195 hp all use the same part number distributor. I have to assume 75 & 76 also. Cap has conventional style cap with wires out the top, not the "crab" style cap. Crab style appears to be used on 351s.

Timing is 10 deg BTDC @ idle RPM. Idle is 500 to 600 in FWD gear with a target of 550.

Also as you discovered long ago, there are different firing orders depending on hp/camshaft. But you have that sorted out.
 
Also, that engine had a ballast resistor in the circuit from the key switch to coil positive stud. There was also a ballast bypass circuit from the starter solenoid to the same coil positive stud. So when in operation (key released, engine running), coil receives a reduced voltage (perhaps 7 to 8 volts) to extend point life. The bypass provides 12 volts (in theory but because the starter draws cranking voltage down to probably 10 at best) during engine start.
Assuming your wiring is still factory then you would need a coil designed for use with external resistor.
If you have a ballast resistor but no bypass circuit for some adulterated reason you will have weak spark while cranking. It stands to reason that voltage thru the ballast circuit would be further reduced during cranking (to maybe 5 to 6 volts).
All that being said, your aftermarket electronic ignition could possibly throw a curve in that reasoning.
 
If I recall, you reinstalled the factory 2 barrel Holley carb?
If so, did you adjust the float level? It is done with the engine idling by turning the screw/jamnut on the top until fuel dribbles out the level screw.
 
I am just a young buck, 74 years. I attached a document with my engine specifics with my as-is wiring schematic, below. It is a 1976 Ford 302 190 hp with GT 40 heads. I did change the timing back to the factory recomendation of 10 degrees BTDC. I did change to an electonic ignition with the Pertronics distributer and 45,000 volt pertonics Flame thrower II coil. It also has Iridium plugs that really light up. I did throw away the old distributer, silly me. I was quite happy to loose the points, gap and dwell...
I believe the carburator is original. I did re-build it about a year ago with a new choke module, so it should be in pretty good shape. I did set the float at exactly level, per the specs. I haven't adjusted it while running, so I need to do that. Gas squirts nicely into both venturi. The choke usually doesn't close all the way at the adjustment that is recommended - I have it loose so I can crank it closed, if it is not starting. It seems to need to be twisted pretty far back to get closed - below the setting marks. Should I leave it there? Or maybe I have it set-up wrong. It has the electronic heat element which after a few minutes it is supposed to open it up by warming up the spring.
So I am just becoming a motor head. I did overhaul a 1957 Triumph TR3-A about 40 years ago - duel SU carbs and a lot of Lucas crap. And a BSA 650 - more Lucas crap. I grew up on a farm, so I have some basics, but am missing a lot. Don't be afraid to lecture me.
 
The bimetallic choke spring can loose its temper over time.
Try adjusting the tension up so choke just closes fully. Disregard the marks for now. After engine start, verify the heat element causes the choke to fully open within few minutes. If it does, try leaving it at that setting. If not, then the spring is probably too far worn out & may need replacing.

What does the Petronics kit say about the ballast resistor? Do they say remove it, leave it installed?
 
Here is the engine data with the wiring schematic - no ballast resistor :
 

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I wasn't adjusting the idle with it in gear, just at idle. So that's one thing, which may handle my fail 3 of my sea trials.
Then there is the float adjustment - I will have to figure out what the level screw is that the fuel is supposed to dribble out of.
Then there is the choke - I believe the spring is in the cap, which would be new - I will have to check that. And to see if it opens up after a few minutes with it adjusted to the butterfly closed.
That may just do it! I have been aiming for reliability, and so far have failed. It should just start up!
On the pertronics, I did adjust the centrifical springs closest to the advance curve of the 302. There were also some advance limiters, and I put in the one with the highest advance of 20 degrres. It is a Pertronics D231800 with a Flame thrower II coil and it is at pertronics.com.
 
From 1974 manual, bottom picture shows level adjustment. Unfortunately 1977 doesn't have this. IDK about 1976.
 

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If no wet float adjustment, then live with the adjustment you made at assembly.
Adjust mixture screws to max idle speed on warm engine then perhaps 1/8 turn out from there. Hopefully both screws will be within 1/4 turn of each other.
 
Engine wiring from 1974, no Selectrim option available in 1974.
 

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Yes, choke spring is in black plastic cap. I guess disregard the marks & adjust as I suggested.
So if I read correctly, you are running 30deg max advance. Specs call for 27deg, plus or minus 2deg.
 
Thanks for the references - some of those diagrams are better tha the ones I have, so I saved them.
I believe I have the float adjustment, so will do that, top off the lower oil, adjust the idle mixture and the prop - I am not sure if I will order a new one, if the old one is okay. I do need to order a trust washer, though. I can't really envision a prop change at sea - leaning over the transom and the drive pin or cotter pin ending up in Davey Jones's locker.
I am not sure I ever measured the max advance, which I believe is the advance at high rpm. I would have to mark it to be able to see it on the markings on the engine. The distributer is somehow separate from that, which I don't really understand, but the advance on it is 24 degrees max without the limiters, It says they are not required, but I put in the highest one, being 20 degree advance. There are two smaller ones. So should I check the max advance? At what rpm? Under load?
Not sure if I will get to this today.
 
Your timing will be base (10deg) plus whatever limiter you have installed. So I guess 30 total at this point.
 
I did make it out and topped off the lower, and it just took a few squirts to fill up, and it was nice and clean green, so I don't think that was a problem.
I don't have a float adjustment, it just has a hump there that is part of the fuel bowl and I don't think I have the overflow window or screw, but there is a recessed hole there that looks like it is just sealed off, as I could not get a screw driver to bite on anything.
It did start right up! I gave it three pumps and set the throttle up for about 2000 rpm. I think it works better setting the throttle higher, as if it doesn't start on that first hit, it usually just grinds, but if it gets enough gas on that first hit, bingo. After it warmed up, I just gave the idle mixture screws both an extra half turn, which didn't change the rpm and it sounded good. I did start it three times after it warmed up and it started right up with no pumps and at the idle setting, which was about 700 rpm, not in gear. I forgot to try it in gear. The choke was set just two clicks back from the recomended three clicks, not further back and I did not take off the spark arrestor to see where the butterfly was, but it would usually not be fully closed. The temperature out was also about 75 degrees, so that probably helped.
Should I set a smaller limiter? The choices are 16 or twelve degrees.
 
I don't have an answer to the timing question. There is a graph if the timing "curve" in my manual. The curve is a straight line. I'm not home to look it up and post a picture. If your running premium non ethanol you are probably ok. Or you could set the timing to about 8 deg & see if it boggs/backfires on acceleration?
What about prop slippage?
 
I think I should put on the 16 degree limiters, as you said base = 10 degrees plus the limiter and the specs call for 27 degrees plus or minus 2 degrees, which would make it 26 instead of thirty, or it says I can mix the limiters and just put in one 16 and one 20, which would be 18 degrees plus the 10 base giving it 28 degrees. What do you think?
I did get a timing curve for a 302 from Makomark and put in the correct springs in the centrifical advance to get it close to that curve as the curve shown in the Pertronix data.
Now looking at the Pertonix data again, there is an alternative wiring for an OMC sterndrive with ESA, electronic shift assist. Is that what I have??? It says to put some "diode and resistors on the ground wire because of the extra voltage at the coil negatve from the electronic ignition. The fix is lowering the voltage (0.5V or lower) to allow the ESA to ground correctly." I have no idea if this applies to my situation. I had thought that it didn't. Any ideas?
I am running regular with 10% ethanol and marine Stabil and a little octane booster, just because I had it around. Non-ethanol is only found at about three stations in LA, and it is over $10 a gallon, and I am not sure of the octane level. All my seals are new and are probably rated for ethanol. Is it worth 2-3 times the cost? I need a good lecture on fuel.
I thought we eliminated prop slippage with my pipe wrench test. I have the mark across the back of the hub, so I will be able to tell if there is any further slippage under load at high rpm. We are hoping it was just some kelp in the prop, but I can check that if it does it again.
 
The ESA is for 78 & newer mechanical shift units.

If you can mix & match, I'd go 28deg. Manual says 27 plus or minus 2.

If your fuel lines, fuel pump & carb kit were all new, you are probably OK with ethanol as far as deterioration of components is concerned. But, remember ethanol will absorb moisture like a sponge until it reaches a satuaration point & then it will phase seperate leaving a unburnable layer on the bottom of the fuel tank.

Here in WI, virtually all premium fuel is non ethanol, about $4/gal. Currently I can buy regular 87 octane non ethanol for just over $3.
 
Vertually all California fuel is 10% ethanol, $4.25 for regular unleaded right now at cheap places. Should I go for higher octane?
The marine Stabil is supposed to help the water problem. I also try to keep my fuel tank as low as possible so the fuel doesn't get old.
I will change one of the limiters to 16 to end up with 18 + 10 = 28 degrees.
Good on the ESA.
I am sprucing up my prop and will be ready for another trip probably next weekend. I use liquid steel epoxy to patch the knicks, sand and paint.
What was your thought on changing the timing to 8 degrees?
 
given the hybrid build and the changes(fuel formulation, especially) since the factory spec was created, I don't think changing the max advance is worth the time at this point...I'd be more inclined to figure out the gearcase/prop issue first....and then get the engine to stay at a stable idle after the cruising period...
 
Changing the limiter is easy, so I am going to go ahead and do that. So, Mark, do you have any ideas on the possible gearcase problem? We are hoping in was just some kelp on the prop, but that was not verified. If it is a internal problem with the lower, I would rather verify the easy stuff before I open up the outdrive. I had so many stripped and broken bolts to deal with when I overhauled the upper. And some of the specialized tools aren't available - I had to guess at how many spacers to use, and just put in the same number that it had before.
The manifestation was like it just slipped out of gear after a few minutes at FOT and engine red-lined and then went back in when I brought the throttle back down and it did it again when I brought it up to 3000 rpm, but at 2500 it was okay. I did not think it was kelp on the prop at the time.
I put a lot of pressure on the prop and it did not budge, so we kind of rulled prop slippage out.
So I plan to go out again probably the following Sunday and try FOT for 10 minutes as a test. I will mark the prop to see if it slips under load, and will check for kelp on the prop if it slips again.
If it is a fail, then I do the surgery on the lower. It would probably be those two springs in there that are $300 each. I would replace most of the questionable parts, so it will probably be about $1000 in parts. I would like to do what I can to have it start and idle in the meantime, if you have any thoughts on that.
 
I did change the limiter, but I found out that what I had in there was the 16s. I thought I put in the bigger ones. So I put in one of the 20s, so am up to 18 degrees - was 16 before, if that changes any ideas on how to procede.
On the carb, Mark, on #35 you said to make sure the vacuum break adjustment is correct. I never found any reference on the vacuum break adjustment. Could you clarify?
 
I went to start it and it started right up with a few gooses and a very high idle. I let it warm up and let it idle at about 600 and put it in gear and the idle stayed the same, not under load. The idle sounded a bit rough, so I upped both idle mixture screws around a bit and was not much change, so I left them about a half turn higher. I started it up three times at idle and it started right up every time, but it did like a little gas, a high idle to come to life.
 
Neal - now that you ask, I think you went back to the two barrel (Holley?) so its no surprise you didn't find a reference to a vacuum break adjustment - I don't think the two barrels use it...
 
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