For this post, I want to share a great trick that I thought, for quite a while, I was the only one that knew about (at least around here). It ends up it’s a trick that some other mechanics have been using for years. They were probably using it before I was born, but anyway, I’d like to pass it along.
It has to do with the process of replacing valve stem seals in gas driven golf carts. The age old issue here is that of keeping the valve from falling down in the cylinder during the process of removing the valve spring, its keeper, the tappet assembly, etc. You can find, if you look around a bit, a tool that you replace the spark plug with that allows you to use compressed air to do the trick. You simply get the piston at the beginning of the power stroke with both the intake and the exhaust valves in the closed position, add air pressure with a compressor, and the valves are held against their seats while you do the work with the valve seats and springs. But it takes a compressor, the spark plug replacement tool and all of that. You also must keep the compressor attached the whole time, because there is a little leakage of the compressed air past the rings so the pressure must be maintained.
What I do to avoid all of that is just get the piston at bottom dead center coming up on the compression stroke, and fill the cylinder with quarter inch rope. I use cotton rope that you can get at almost any hardware store. It’s real cheap and I’ve been using the same 5 foot piece for over 10 years. It’s a little crusty by now, but it still works just fine. Just remove the spark plug and feed the rope down the cylinder. I use some long nose pliers to get it started. Once the rope is in place, just continue to move the drive clutch on the crankshaft by hand to move the piston up the compression stroke until you can feel the rope being tightly compressed against the valves. You can tell when it’s in the proper position because you can’t feel any (or much) movement of the valve when you push down on top of the stem. You are then safe to remove the hardware to get to the valve stem seal, replace the spring and keeper(s) and then just back the piston off a little and pull the rope out, and you’re ready to adjust the valve clearances and be done with it.
If you haven’t removed the spring and keepers before, there is one thing to be very careful with. There is always an oil return opening or two at the bottom of the area that you are working in on top of the head and it is extremely easy to drop one of the valve spring keepers down one of those openings right into the crankcase. You don’t want to have a keeper drifting around in the crankcase. It can get into the wrong area and do a bunch of harm. Let’s say it gets in between the gears of the crankshaft and the camshaft or balancer. You can imagine what could happen the instant it jams things up. To avoid this, be sure to block off that opening(s) with a rag, paper towel or whatever, so that if you do drop a keeper, you will be able to retrieve it with a magnet or tweezers or pair of pliers. Trust me. I have dropped them before. On one occasion I was working on a 2 cylinder EZ-Go and thought I had the oil returns plugged up, but while I was removing the keepers, one of the keepers took off to parts unknown. When I double checked the return openings, sure enough, I had not gotten one of them completely blocked off. I couldn’t be sure that the keeper hadn’t gone through the space that was left open, so I spent the next several hours fishing around through the opening that is exposed when you take off the oil filter with a magnet to try to find the missing potential source of a catastrophe. Thank goodness, on this model, when the oil filter is removed, there is a reasonably large opening that you can work through. You can even shine a flashlight into the opening and look down the oil returns and see the light. On other models, you just have to try to work through the return(s) and try your luck. On this type of engine, the return holes lead directly to the crankcase with no obstructions, so the keeper should have been easy to find through the oil filter opening (with a magnet on a stick), but despite all of my efforts, I never found it. I even added new oil, ran the engine for a few seconds and then drained the oil and repeated the fishing excursion several times, but no keeper (valve spring keeper, not fish). I finally gave up and had to assume that when it took off, the keeper went somewhere else (I never found it). The good news is that to this day, it has never messed anything up. I have people tell me “oh don’t worry about it, it is ferrous metal and therefore quite heavy and it will just lay on the bottom and not be a problem”, but I’m skeptical. If you want to take your chances, you are much braver than I am. Obviously on this model, the keeper won’t be able to get into the oil pump because the oil filter acts as a screen to protect the pump, but it’s the gears that scare me.
Once again, I thought at first, that I had really come up with something clever the first time I used this technique. I call it the “Rope Trick”. I was sure disappointed to find out that that the trick had been around forever. Anyway, I hope it might help someone you know who is getting ready for a valve stem seal job.
Ron Staley has published the following books, and you can get more information about them by just clicking on each title below:
Electric Golf Cart Repair 101 (and a half)
Techniques, Tips, Tools and Tales
Gas Golf Cart Repair 101 (and a half)
Techniques, Tips, Tools and Tales
4-Stroke Golf Cart Engines Explored
What Makes Them Tick
By an old Slot Machine Mechanic
3 replies on “Rope Trick”
I like this trick. It is much easier than using compressed air.
I’ll try it tomorrow.
Thanks for the comment.