My 1997 Stihl TS 510 Brazilian made cut off saw (same metal base as a chainsaw, carb's a Tillotson) ran well for 10 minutes, then lost power if under load, but would spin up if not under load and sound ok, but bog down again if loaded. So, I replaced the ignition coil with Stihl part and it coughed once after a couple pulls but didn't start, then I have a very short shot of ether, ran for .5 second, then, no more signs of starting. Pulled carb, looked at hoses, cleaned carb with brake cleaner, diaphragms look good, it ran a second on first pull, then no coughs, nothing. The upper seal on the carb, just below air filter is not completely torn, but is thin and tattered. There is a very small gas leak, a few drips around the hose attachment onto the big rubber fitting that pushes with some effort into the metal hole the hoses run through to the gas tank. IDK if the Tillotson is original, or the last guy had problems? I took the hoses off, blew through them, no visible issues. I think it's a fuel issue. What's my next move?

Far too often people get one of those silly little pressure gages that have a female hose thread adapter and attach that to a hose bib or laundry faucet and blindly assume the pressure they see is the actual working pressure of their system but such is not the case. When you attach one of those gages to a faucet then open the faucet to take the reading the gage is blocking the outlet thus for all intents and purposes they are still recording the pressure in a closed system. The basic laws of physics state that the pressure will remain constant at all points in a closed system however, the moment that we open a faucet and allow water to flow the pressure throughout the system immediately drops to "Dynamic Head Pressure" or more commonly stated as "Working Pressure." Dynamic head or Working head pressure is Static Head pressure minus "Friction Head Loss" and "Vertical Static Head Loss". Water physically weighs 0.434lbs per vertical inch column therefore to compute vertical static head loss we must measure the actual vertical rise from the point where we measure the pressure to the point of demand. As an example; let us assume a two-story house where the water line enters the basement near the floor and the shower is on the second floor. Typically we would have an 8 rise to the ceiling plus 1 for the floor joists and flooring material on the first floor, 8.5 to the ceiling and another 1 for floor joists and flooring material to the second floor and finally a 5.5 rise to the showerhead for a total vertical rise of 24Â. The vertical static head loss from the main water shutoff valve to the showerhead would then be 0.434psi x 24 = 10.4psi loss. Now assume that we measure the pressure at the main water shutoff valve and we get 45psi. This means that the absolute maximum pressure at your showerhead would then be 45psi minus 10.4psi = 34.6psi. From this we would then need to subtract friction head loss to determine the actual pressure at your showerhead. In the original post they stated that the pressure and volume is fine when only one faucet is opened but it decreases rapidly as two or more demands are opened. That is because "Friction Head Loss" increases dramatically as the velocity of flow increases. By example, let us continue to examine what happens if just the shower is used. Let us assume that in addition to the 24 vertical rise there is a 10 horizontal offset from where the supply line enters the basement to where it rises up to the shower therefore the total length of the line inside the house from the water main to the shower is 24 vertical plus 10 horizontal for a total of 34Â. (Technically we would need to also add in the fitting insertion losses but for now we will disregard them). The post states that they have a ¾" supply line that is 200 long. Let us assume the line to the shower to be a ½" line 34 long and the shower is rated for a flow rate of 2.5gpm. We measured 45psi at the main water shutoff valve and as was previously stated the pressure is constant at all points in a closed system so it then stands that the pressure at the prime mover (municipal main) is also 45psi however when flow begins friction head loss also begins at the prime mover. The post states that the existing supply line is ¾" and let us assume it is continuous roll PE-SDR pipe (black poly-which has one of the lowest friction loss factors). Consulting the PE-SDR friction loss table we find that at 2.5gpm the loss is 1.5psi/100ft and we have 200 so the loss is 3psi from the municipal main to the main water shutoff valve. Assuming the ½ line to the bathroom is copper we then consult the type L copper pipe friction head loss table and find that for the 34 run from the main to the showerhead we have a net loss of 0.118psi/foot x 34 = 4.02psi so at 2.5gpm the total friction head loss is 3psi + 4.02psi = 7.02psi (round off to 7psi) The static head pressure was 45psi and dynamic head pressure is static head pressure minus vertical static head loss + friction head loss so the actual pressure at the showerhead is 45psi  7psi  38psi. That is not bad pressure if we could be assured that no one would turn on any other fixture while we are taking our shower however the plumbing code requires that when we design a water supply system it must be capable of maintaining certain minimum pressure standards in a worst-case scenario where all the demands in the structure are open simultaneously. Under the UPC we would use the FU (Fixture Unit) method as I described in my previous post whereas under the IRC we use a minimum gpm rate for each fixture. Both methods will ultimately arrive at the same solution so for simplicity let us use the IRC demand rates here. Bob sent me an email stating that he has the following fixtures: 4 sink faucets 2 toilets 2 bathtubs 1 shower 3 hose bibs outside When I examined the list I was a bit confused. With 2 toilets I am assuming he has two bathrooms and one of the sinks is obviously a kitchen sink so I am guessing that he has a master bath with both a tub & a shower and perhaps 2 lavatories but on the other hand one of the sinks could also be a laundry sink. From IRC table 2903-1 we get the following minimum pressure and flow rates to each fixture. BathtubÂÂÂÂÂÂÂÂ.4gpmÂÂ8psi Shower (temp controlled)Â3gpmÂÂ..20psi LavatoryÂÂÂÂÂÂÂ..2gpmÂÂ.8psi Kitchen sinkÂÂÂÂÂÂ.2.5gpmÂ.8psi Water Closet(tank type)..Â3gpmÂ....8psi Laundry hookupÂÂÂÂ..4gpmÂÂ8psi Hose bib #1ÂÂÂÂÂÂ.5gpmÂÂ8psi Hose Bib#2ÂÂÂÂÂÂ.5gpmÂÂ.8psi TOTAL LOADÂÂÂÂ28.5gpm Although not mentioned, if he has a dishwasher that would add another 2.75gpm. Now let us examine the Friction loss table once again. With a flow rate of 28gpm the velocity of flow through his ¾" PE-SDR line is 16.82feet/sec or more than 4 times the maximum allowable 4ft/sec and at this rate the line will exhibit severe pipe wall and fitting erosion resulting in premature line failure and the friction loss is 59.41psi/100 of pipe. Given that his line is 200 long @ 28gpm the total friction head loss is 2x 59.41psi = 118.82psi thus the friction head loss is more than twice the supply pressure of 45psi and with all fixtures open at best he would barely get a trickle of water and no noticeable pressure. Even increasing to a 1" line would still result in a 36.5psi friction head loss from the municipal main to the main water shutoff at the house. On the other hand if the line from the main to the structure was increased to 2" the friction head loss through the supply line would be reduced to 1.36psi and the resultant pressure at the house main shutoff valve would be 45-1.36= 43.64psi which remains slightly above the code minimum supply pressure of 40psi.

Ron, I can't see the need to get hostile toward anybody on this topic. You and I and many others have lots of experience with cabling. I agree with your statements as my comment stated. In our power plants we brought the Belden twisted pairs into the cabinets with the jacket stopped at times a foot and a half or more from the device, (RTD monitors, recorder or PLC, or what ever), and untwisted the pairs because they went to different locations. This never caused a problem. As you know what does cause a problem or can cause one is grounding the shield at both ends of the cable. We usually had a 5 or 6 ft long copper ground buss that we made up( drilled and tapped) and mounted it in the cabinet. There we terminated the bare shielding wires from the many cables. Soldered Burndy lugs on all ground and signal carrying conductors. Clamp or pressure terminated wires were used on some equipment that had those kinds of terminations, however they were avoided as much as possible. One problem with them was it made it harder to lift and lay back down the wires during troubleshooting or testing as the wires fray and are difficult to get back under the screw, especially when energized. And we had one guy that always made the strands of wire look like a worn out paint brush when he laid down those wires. At least 1/4 of the strands were sticking out. Terrible! One time we got a new pre-wired cabinet in from a manufacture and when we were putting the equipment into service it was not working. So naturally we looked at our own wiring and found no wires laid down wrong. After much troubleshooting we found where the manufacture had stripped the wire correctly but got the insulation under the screw where the conductor did not make contact. Boy that drove us crazy! Anyway, from one old sparky to another, good luck.

As the proud owner of a ca. 1825 farmhouse, I understand a lot of the challenges and adventures that come with playing "this old house", and it sounds like you have your share too! That said, I have no idea what it might take to rework your plan to take power from the main panel instead of that unused two-wire ungrounded circuit. Any chance you could pull a new cable there with an equipment ground and maybe a bit more ampacity? The lack of a ground at the point of hookup is definitely a problem and it all but guarantees that any "solution" you try will violate modern electrical codes. I think I understand the ground rods providing some protection against lightning and other surges but not being conductive enough to create overcurrents that will trip a breaker (though surely strong enough currents to trip the GFCI I plan to place on the barn branch circuit). Actually, equipment grounds have little or nothing to do with the operation of a GFCI. Because a GFCI works by monitoring the hot and neutral and only trips when they are out of balance, a GFCI doesn't even need a ground wire to function properly. But you should also keep in mind that, while a GFCI protects against ground faults, it doesn't provide overcurrent protection. Thus, in the case of a short circuit, the heat can start a fire while a GFCI continues to feed power! "Actually, as a side note, I once measured an impedance of about 10 ohms in a ground rod circuit. Indeed not low enough to generate the 20amp overcurrent to trip a breaker at 120V." Yep, you're spot on there and, actually, 10 ohms is better than average! With this in mind, you may have wondered why I recommended two ground rods. It's because recent code editions allow a single ground rod where the impedance is 25 ohms or less. If a single rod flunks this test, a second rod is required and many single rods do, in fact, flunk. Don't ask me why (practicality, I'd assume), but the two ground rods together don't have to pass the test--they're just presumed to be OK. So it ain't all pure science, if you catch my drift. :-) "I am starting to get the feeling that unless I establish a (green) equipment-ground wire in the house circuit and connect it to the main panel, there is no way to take electricity to the barn and still meet code." That's my take too. "I assume that by equipment-ground you mean the wire that is normally green in color but sometimes grey or bare copper. Yep. (While gray is technically designated as an alternate color for neutrals, those old green ground wires do sometimes look gray.) 1. Maintain separate neutral and ground bars in that panel. (You may have to buy a small ground bar for a couple of bucks or, if there are two bars and they are connected, they need to be disconnected.) There is only one bar in the small barn subpanel. But no problem, say I buy a small separate ground bar. If you still have the packaging materials, they'll probably say somewhere the correct part number with the notation "sold separately." (Thanks, folks.) It's best to use the designated part although, in truth, those short ground bars are fairly interchangeable. 2. In your house, connect the equipment ground wire to the ground bar. In a main panel, there is often only one bar, serving both neutrals and equipment grounds. (That's fine in a main panel. In a subpanel, however, they should be separated.) There are no equipment-ground wires in any of my house wiring. That is, there are no green, gray or bare copper conductors anywhere. All wires in my house are 2 conductor wires, just one white and one black (hot+neutral). The only ground (bar) is inside the main panel where the neutral from the utility pole attaches. See, for now, I was planning to feed the barn circuit from an existing, unused, 20amp two conductor (black+white) house circuit. This house circuit was originally used to feed an old radiant space heater in one of my bathrooms (that bathroom is the closest room to the barn anyway so tapping into that circuit for the barn is most convenient). I disconnected the old radiant heater a long time ago for safety reasons and since that was the only appliance on that circuit, this circuit is now unused and available, I assume, to feed the barn. But it is strictly a 2-conductor wire (black+white only). Sigh, I feel your pain. (Really! No sarcasm intended.) 3. At the barn, connect the equipment ground feeder to the subpanel ground bar and land your branch circuit ground wires there too. In other words, all the (green) equipment-ground wires go to the subpanel ground bar. However, there is no existing (green) equipment ground wire coming from the house. If one is needed I would have to install one on a separate route and run it all the way to my houses main panel. True, true and true. (Not to get too picky here, but technically speaking, the EG is supposed to run in the same cable or raceway, btw.) 4. Drive two 8' grounding electrodes (ground rods) at least 6' apart and connect them to the panel ground bar with #6 copper wire. Again, from what I understand, unless I install that (green) equipment-ground conductor from the house main panel to the barn, then I should probably not ground/earth the barn subpanel at all. IMO, earthing the barn panel is a good thing in any event. What is to be avoided is a "false equipment ground". (That's a made-for-purpose term meaning that if the EG's are connected only to a grounding electrode, it may create a false confidence in addition to a code violation.) Somewhat better (although not fully code compliant!) would be to bond the neutral and the grounding electrode at the barn's ground bar. (That is what is done with a so-called three-wire 120/240V outbuilding service--the neutral effectively serves to feed both grounded conductor and grounding conductor.) But note that, as ronnatalie has correctly pointed out above, this approach is not strictly applicable in your case because there are other metallic connections (e.g., the phone wire) between buildings. Now that would take another long-winded discussion, but suffice it to say that the code only permits a neutral-EG bond when the house and outbuilding have no other connections. That may be a technical glitch, but it's a potential violation nonetheless. If I do run the (green) equipment-ground wire from the barn to the houses main panel then I should probably ground/earth the main panel only using rods implanted somewhere close to the main panel. If your house really has no earthing system, that would be a wise improvement in any case. It might also be useful to evaluate your plumbing as a potential source of earthing. If your water service is metalic when it enters the house, and runs at least 10 feet in the ground, you should also connect the water supply at the point of entry to your main electrical panel. With an old house, seemingly simple projects do tend to mushroom, don't they?