uglydukwling
ArboristSite Member
I recently replaced the Wisconsin V-4 engine in a lift with a used unit. It ran when the seller demonstrated it. It ran after I installed it, and I used it for maybe a half-hour total. Then it sat for a month, and hasn't started since. It fires, but won't catch long enough to run.
It has fuel. I first replaced the mechanical pump with an electrical, then a gravity tank. No change. The float bowl fills, and gas doesn't drip from the carb. It fires on starting fluid, but no differently from the way it does on gas. When it was running, it ran fine on the gas that was in the tank, which was a year old, probably more. I filled the gravity tank with fresh gas. No change. One of my friends came back from an engine show, and someone there told him to use fresh premium gas. It doesn't make sense for a low compression engine like this, but neither does anything else about this situation, so I'll try it.
It has spark. With the plugs out, I get spark at all of them. The plugs looked new, but I replaced them anyway. No change. It has the Wico magneto, if that's a clue. I noticed that the plugs in both the original and replacement engines were gapped at .018, so I tried them that way as well as the .030 the manual specifies. No difference.
It has compression. The manual says that it's normal for these engines to lose compression if they've been stored for a long time. It recommended putting a tablespoon of oil in each cylinder. I did, and compression came up from 60 to 100 psi, but still no start. Even if it had a dead cylinder, this engine should run. The one I replaced started and ran (almost smoothly) with a hole through one piston.
The only thing left is timing. That's what I would suspect if the engine had been apart, or if it had a timing chain. But the timing must have been right the first time I used it, and timing gears can't jump like a chain can. The only way for a gear to jump is to strip teeth, and then the camshaft and magneto wouldn't turn at all. I guess I have to check timing, but the engine is a rather tight fit in it present installation, and I'm not sure I'll be able to see the timing marks without removing it.
I'm down to considering replacing the engine again. I have located a pair of V-4s, but they aren't running. The usual "they were running when we pulled them" story. The reason I bought this one was that it was running and I'd have had to take a chance on the others. One thing about the others is that they're both coil ignition, and I've had better luck diagnosing it than magneto ignition. I'm even considering a different engine, but this machine is set up for a Wisconsin. The bolt holes line up, etc. The bigger problem is the length of the engine. There isn't room for anything longer than the Wisconsin. That's why I didn't just drop in a 4-cylinder auto engine the first time around. Also, I need the stub shaft to mount a 4-groove pulley. If I use an automotive rather than industrial engine, I'll have to fabricate something. Can anyone think of anything that might fit?
It has fuel. I first replaced the mechanical pump with an electrical, then a gravity tank. No change. The float bowl fills, and gas doesn't drip from the carb. It fires on starting fluid, but no differently from the way it does on gas. When it was running, it ran fine on the gas that was in the tank, which was a year old, probably more. I filled the gravity tank with fresh gas. No change. One of my friends came back from an engine show, and someone there told him to use fresh premium gas. It doesn't make sense for a low compression engine like this, but neither does anything else about this situation, so I'll try it.
It has spark. With the plugs out, I get spark at all of them. The plugs looked new, but I replaced them anyway. No change. It has the Wico magneto, if that's a clue. I noticed that the plugs in both the original and replacement engines were gapped at .018, so I tried them that way as well as the .030 the manual specifies. No difference.
It has compression. The manual says that it's normal for these engines to lose compression if they've been stored for a long time. It recommended putting a tablespoon of oil in each cylinder. I did, and compression came up from 60 to 100 psi, but still no start. Even if it had a dead cylinder, this engine should run. The one I replaced started and ran (almost smoothly) with a hole through one piston.
The only thing left is timing. That's what I would suspect if the engine had been apart, or if it had a timing chain. But the timing must have been right the first time I used it, and timing gears can't jump like a chain can. The only way for a gear to jump is to strip teeth, and then the camshaft and magneto wouldn't turn at all. I guess I have to check timing, but the engine is a rather tight fit in it present installation, and I'm not sure I'll be able to see the timing marks without removing it.
I'm down to considering replacing the engine again. I have located a pair of V-4s, but they aren't running. The usual "they were running when we pulled them" story. The reason I bought this one was that it was running and I'd have had to take a chance on the others. One thing about the others is that they're both coil ignition, and I've had better luck diagnosing it than magneto ignition. I'm even considering a different engine, but this machine is set up for a Wisconsin. The bolt holes line up, etc. The bigger problem is the length of the engine. There isn't room for anything longer than the Wisconsin. That's why I didn't just drop in a 4-cylinder auto engine the first time around. Also, I need the stub shaft to mount a 4-groove pulley. If I use an automotive rather than industrial engine, I'll have to fabricate something. Can anyone think of anything that might fit?
