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Major snow storm 1976 JC LP surging - help!


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  #1  
Old 02-25-2010, 09:28:25 PM
mike sylvester mike sylvester is offline
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Default Major snow storm 1976 JC LP surging - help!

Well it's what we've been waiting for, Major snow storm(northern nj, 24"). My 1976 JC LP has tested fine for months, big blue arc in the sky and poof, no power. I waited 1/2 hour to see if it would come on before i fired my baby, started up and ran great for 30 min. then started to surge. Tried a few adjustments, nothing. took side cover off and saw the gov. arm going up & down, held it steady and let go, now running fine. It's 8:30pm here & won't go to bed until i figure out why she is surging (was) so far so good! Don't want her to start surging when i'm sleeping. What caused this??
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Old 02-25-2010, 09:47:20 PM
Wayne 440 Wayne 440 is offline
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Default Re: 911!!!!!

I had one years ago that did that once in a while. There seemed to be some mysterious combination of loads in my house that would make it start hunting, then the only thing to do was grab the linkage manually or drop the whole load and pick it all back up. No individual load I could turn on or shut off would settle it back down.

Mine was a 12.5 JC on gasoline, it worked fine after I decreased the governor sensitivity just slightly. I think you go in clockwise direction to decrease, but you will want to check the book. Since yours is LP, this may/may not be sound advice, proceed accordingly.
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Old 02-25-2010, 10:14:42 PM
richard.bessey richard.bessey is offline
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Default Re: 911!!!!!

I have also had similar type surges with certain types of loads. Do you have fan motors or something kick in/out?
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Old 02-25-2010, 10:33:45 PM
pegasuspinto pegasuspinto is offline
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Default Re: 911!!!!!

check for slack in the governer linkage, check that the linkage is all moving freely. it may not do it again now that it's warmed up. I'd go to bed and worry about it in the morn'

Robert
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Old 02-25-2010, 10:43:04 PM
mike sylvester mike sylvester is offline
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Default Major snow storm 1976 JC LP surging - help!

No big loads, fridg, well tv lights & furnace. This never happened before, been running fine now for two hours, We have a blizzard going on, tree are leaning everywhere! Going to be a fun night!!

No slack gov. arm is a solid piece to carb.
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Old 02-25-2010, 11:24:51 PM
Jim Rankin Jim Rankin is offline
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Default Re: Major snow storm 1976 JC LP surging - help!

I had a big one do something like the same thing, only it was pretty impressive, it would stumble and backfire. IH 549 V-8.

Turns out the LP gas co had replaced the regulator feeding it and it was too small. If I restrained the governor arm, I could get it up to speed and then it would handle most anything that the dairy barn it was attached to could throw at it. Only one large motor could bump it enough to set it off sometimes, and then it would go to stumbling and backfiring. With the previous regulator, none of this happened, it ran like the beast that it was supposed to be.

I bet it's just colder than it usually is and you had some combination of loads that created a Wide open throttle event for a second that the LP system couldn't meet the demand. Could have some sort of crud in a regulator restricting it a bit.
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Old 02-25-2010, 11:39:05 PM
Wayne 440 Wayne 440 is offline
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Default Re: Major snow storm 1976 JC LP surging - help!

If it has run OK for 2 hours, I would say it was just "Murphy" at work. Turn all your lights on, and sleep well.
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Old 02-25-2010, 11:44:34 PM
mike sylvester mike sylvester is offline
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Default Re: Major snow storm 1976 JC LP surging - help!

Jim, you might be right, the 500 lb tank is older but the regs, 1" lp line are new. I think its a fuel/reg. issue. never happened before under load. Only thing different from last time running is i replaced the point ignition with a pertonix 1545, flamthrower coil & accel ign. wires
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Old 02-26-2010, 12:07:54 AM
Ted_Cool Ted_Cool is offline
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Default Re: 911!!!!!

Turning the governor screw adjusts the speed, not the sensitivity. I recall the book seems to imply that you can somehow jump the spring on the notches using the screw, but I like to see for myself what actually happened.

Moving the spring end up a notch will decrease the sensitivity. I've always left mine on the most sensitive setting without problems.

Similar problem for my JC tonight - It never had a problem during test runs, now tonight the power quit, and when I started it, it wouldn't come up to speed for almost a minute. It fixed itself suddenly and ran like a champ. I've never had that happen before.

I guess now I'll have to look over the governor and throttle to see what's up.
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Old 02-26-2010, 12:35:18 AM
mike sylvester mike sylvester is offline
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Default Re: Major snow storm 1976 JC LP surging - help!

Powers back on, my girl ran well. Surged twice? Will have to investigate tommorrow, been plowing, going to bed. Nighty all & thanks
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