# 53 Jubilee- Fuel Starved? Or Carb Issue?



## mrlewp87 (Apr 26, 2014)

*Had this Jube running great last fall. Then one day, heading for the pasture, it stopped cold. Since that time, it would never run for more than 10-20 mins. at a time. Recently, even shorter periods. 
Weeks ago, I started out looking into the electrical system. All seemed to be in order... more or less. (more on that, later)
Then, focusing on the fuel and carb side of things, I siphoned gas from the bottom of tank. Yes, there was crud, or rust. I then drained the lines, siphoned again, cleaned the screen in the carb's fuel intake. My feeling of bliss was short-lived, as it started right up, ran for 2 minutes, then quit cold again. 
Suspecting that the carb intake screen was again clogged, and perhaps the shut-off valve and screen also, under the tank.... I knew what I had to do.
Now I've removed the tank, removed the shut-off, cleaned the screen, flushed out the tank using what I had on hand- a fuel conditioner, before than rinsing it with about a quart of gasoline. Using a flashlight, I couldn't see much in the way of rust on the inside surface. But since the sediment bowl wasn't part of the package when we bought the tractor, I decided to add an in-line fuel filter- yes, meant for gravity fed fuel systems. I did a great deal of reading on this, and surely found more positive stories than negative 
Finally now re-assembled, all NEW 1/4" fuel line used, all screens clean, fresh gas (with Ethanol additive), and I'm very hopeful. Alas ..... there was no improvement. I had to choke it to death, and do repeated crankings of the starter, before it even attempted to run. At best, about 20 seconds.
I went to great lengths to make sure the the entire line that the fuel flows, is downhill. I had noticed that there was a slight uphill from the tank valve, then again leading up to the carb fitting. I never cared for this, but ignored it because as I said up front, the ol' JuJuBee ran great last fall. Hours, not minutes.
With the see-thru in-line filter, I can now see a very tiny trickle of fuel coming from the tank. Absolutely identical to what I saw before going to the extra efforts in removing and cleaning the tank! In fact, while cleaning the shut-off valve and screen, I couldn't help but notice the really TINY hole that must allow fuel to "dribble" into the fuel line I'd safely claim that an 1/8 " drill bit would be too large to insert into the hole. This is confounding to me, as it cant even fill the fuel line, which is 1/4 ", with the internal diameter being for sure more than 1/8"! How can this maintain the fuel supply required to run the engine? I'm no mechanic or engineer, but it just doesn't LOOK right. Ever hear of anyone drilling out that hole to enlarge it? ( I know, you'd have to do a right-angle to lead into the flared start of the fuel line)
The coil is new, because I had left the key on.(again!) I have since read that the condenser could go bad from an over-voltage condition. The tractor had been converted to 12V, and I understand that the distributor and it's parts are only available in the original 6V types. I read that the condenser may work ok until it gets too warm, than fail again until it can cool down. This would permit arcing to occur, causing mis-fires in the least
Seems keeping this tractor running well is a common problem, but I've yet to find a cure in all the reading Ive done. I'll admit to having no experience with carburetors, but fine-tuned this one using forum notes. That's when it was running fine, last fall. I'd hope to do all I can, and avoid removing it, unless it becomes the prime suspect here.
Thoughts? Helpful hints.*


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## pogobill (Jan 31, 2012)

Sounds like you have gone over the fuel system quite well. One thing you didn't mention was the fuel tank venting. Check that as well.
Other than that, did you replace the coil with an after market 12 v unit, or an original 6 v unit. If it's a 6 v, you need to ensure that the conversion was done with the kit supplied resistor installed properly and that it is working. If you put a 12 v coil in, you may need to by-pass the resistor.


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## mrlewp87 (Apr 26, 2014)

pogobill; I forgot that I had covered the conversion by a prior owner in another post. (yesterdaystractors.com- "To Resist, or Not To Resist?", or a similar corny title) *12V Alternator-single wire, "self-exciting", no voltage regulator.
*12V coil- enclosed notes, or package states "No Resistor Required". I suppose because it's internal resistance holds the current under 4 amps, which I've read is the max. allowed to prolong the life of the points, plugs and condenser.
There was no resistor or regulator when I bought the Jube, and after fine-tuning the idle, large and small screws on the carb- I had our JuJuBee really humming along last fall. That's why this is so frustrating, having gone back and forth in the forums, and with parts dealers regarding the electrical system. 
And now, needing to question the skimpy fuel flow from tank to carb, because it also was the same last fall. BUT, for the addition of the in-line fuel filter. After all the effort put forth removing and cleaning the tank and replacing the fuel line, I was actually hoping to SEE the filter trapping some crud from the tank. Not a spec !! as of yet. Did I note that I had siphoned rust (assumed) from the tank, and trapped it coming from the old line. Then I opened the carb drain, and was aghast at what came out, before feeding clean fuel from the cleaned tank to it. This was super-fine, which got by 2 screens. It was like a fine black dust or soot in the fuel. I'm sure there's several problems this could cause for the carburetor, from what I've read. 
Today I started her up, and it started on the first turn! Ran absolutely smooth as I've ever heard it..... until once again, it just stopped, as if the key was turned off. I was able to repeat this event soon afterward. Thing is, it used to run for about 10-20 mins. before quitting. Now more like 2 mins. It's been suggested that it would run until the carb emptied it's bowl of fuel. I dont think I've been allowing it to fill lately, because I usually catch it leaking when it does. I've come to learn that's all too common also, so am sure to shut the fuel off when not needed. ** Air in the lines? In the filter? (Yes) Nothing I've tried causes the filter to fill up. I'll have to disconnect it, fill it, then quickly attach the line again. But having to repeatedly turn the fuel off at the tank- a problem there? 
>> Another thing confounding about this fuel flow issue- we also own an old Yanmar, diesel- and gravity fed! I eventually thought to have a look at it. To my amazement, the line goes down to a filter-which IS full of diesel- then takes a 90 degree upward turn, about 6 inches. What's more, the tank is maybe half the distance above the filter (and the 90 dgr.upturn), as the Jube's tank is above the carb. Think "gravity" here. Is diesel heavier? The diesel line is larger, that's for sure. I just cant get over the pencil-lead diameter of the hole in the Jube's shut-off valve!? If under-stated, I'll guarantee a 1/8th in. drill bit wont go into it.
I truly apologize for my word count here, but I'm left with a question over your remarks. If it's true that the distributor and it's parts have always remained as 6V, even after the 12V conversion- why did the 6V version require the step-down resistor, and NOT the 12V? Ok, had to remind myself that it was a 6V coil, therefore less internal wiring resistance. But also only 6V, so still curious.
Finally, another update from today- I was betting, and really hoping to measure the capacitance of the condenser to find that it was way off the mark. Unfortunately, using my DMM, it measured nearly exactly the same as the new condenser that came with the points I bought. 24 uf. The new one read as 25 uf, or right on the mark, from my research. Is it possible it only fails after in use for a while, but measures OK when cold?


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## bensdad (Mar 2, 2014)

Your Jube is acting just like mine. I know what the problem is. You're not gonna like it. That's why I haven't done mine yet (procrastinating). 

Pull the oil filter. You will find foam. You either have a cracked block (not super likely, but possible) or a compromised head gasket (WAY more likely). Have fun. 

Sorry to be the bearer of bad news.


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