High Altitude Jet for 7,125-Watt and 10,000-Watt Firman Generator - 3,000' to 6,000'

Video Transcript for High Altitude Jet for 7,125-Watt and 10,000-Watt Firman Generator Review

Randy: Hey guys, Randy here at etrailer.com. Today we're going to be taking a look at the rejetting process for the Firman, the bigger generators, 439 CC engines. It's going to be the 7,150 watt and the 10,000 watt. Basically, by rejetting a carburetor, we allow it to work better at higher altitudes. We've got a 3 to 6,000 foot jet and a 6 to 8,000 foot jet.Basically, what these are going to do, they're going to thin out or reduce the amount of fuel going in. As we get up in those higher altitudes, we have less oxygen in the air.

When we have less oxygen in the air, we need less fuel. It helps to restore some of the efficiency. Generally, as we get higher and higher above sea level, our generator gets lower and lower as far as its effectiveness goes. It's about 3% per 1,000 feet. By doing this, we help to restore some of that.It also helps to get rid of some of the stumbling that we sometimes have, like the carbs overloading.

What we're going to do is just remove the panel and show you the process to get in there. Now, I don't like rejetting a carburetor if I don't need to.The way I like to do it is, when I'm going up into those higher altitudes, I'll get the jet kits, I'll have them with me, and I'll use them if I need them. If the generator's running fine, if I'm getting all the power I need, I won't rejet it. The one side effect to rejetting an engine or a carb is that it's going to run just a little bit warmer. If I don't have to do it, I won't do it, but if you need to, it could be critically important.

You get up there and your generator's not running properly, well, you have issues. You're not getting the power that you need to supply whatever you need to supply.It's pretty basic tools that we need. We're going to start right here behind this air box. We'll start by moving our choke over out of the way. Got these clips.

Just rotate those down. That's what allows you to get in there to your air filter element. See that right there. We'll pull that out. Once we've got that cover out of the way, you'll see the nuts that we have going all the way around here. That's going to help us remove this plastic piece. Let's take care of that now. For these we're going to use a 8mm socket. Get them broke loose and then removed. We'll take that guy off. Then we can see this one and this one that we need to remove.Then right behind where that stud's located there's another one on the backside that we'll take out. You can see our hose here. Want to get that pulled up and out of the way. Then there's one here. We're also going to pull that out. Then we'll use a 10mm to get these removed. Just pull that off of there. Got a little paper gasket here. Just want to be sure that, while you're working on this, that that stays intact either on there or, if you pull it off, put it back in place as you're reassembling.Then we'll move right down here. We're going to have two screws right there. You can see they're hex bits. We'll take this one and this one off around on the backside in the same spot. Here we're going to use a 5/32. Want to get in there and get those loosened up inside and out. Pull that down so that it rests there. That'll give us access to the bolt there that we need to remove so we can drop our bowl down.For this one we're going to need a 14mm. This is also the point that you're probably going to get some fuel leakage. We dried ours out pretty good. You can place a towel in here and loosen the bolt here on the side. That's a bowl drain. But even with that being done, you're going to have a little bit residual so just keep that in mind. Just hold our bowl in place while we remove that. You can see the little rubber O-ring that's on there right there. We need to keep that intact so just hang on to that. Allow that to come down. Then you can see the seal has stayed right up in here. Your kit will come with a new seal. But if it doesn't move, if there's no rips or no tears on it, I generally just leave it in place.Now we're going to take a very narrow screwdriver. You want it to be narrow this way but have a pretty good thickness that way. We're going to put that right up into the jet. You'll feel it when it bites in. Then just gently remove it. Now, we want to keep in mind this is brass, so we want to be gentle with it. Right above it you'll see that. You want to hang on to that. We'll need to put that right back up in there. The double lip needs to go to the bottom when we reassemble it.Now the tube'll go back in. Our jet will go back in. And we need to get it threaded in there properly of course. Want to give it a little bit of pressure. We don't need to torque it to any kind of crazy spec. We just want everything to stay intact. Now it's just time to reverse the process. We'll place our bowl back on.Now we're just going to go through and reverse our process. Once that's in place, we'll get our hoses put back in. They go in pretty easy. This one sits right down on that little lip. We'll just get it pushed down there far enough to where it grabs ahold. Now we got the element holder that's going to back on. These should be down. Get them all started and then tighten them up just a little bit. Once the element's back in place, it's just time to put our cover on. At this point it's time to fire her up. Want to check for leaks of course, make sure you don't have any fuel leaks. Probably before you fire it up, check just to make sure you don't have any excess gas or anything laying on anything. We certainly don't want it on the exhaust. Clean up the gas, then fire up the generator, make sure you don't have any leaks, and as long as you don't, you're set and ready to roll.