Category: Engine

Before closing out the skin above the firewall, I really wanted to address an Alert Service Bulletin (ASB) issued by Rotax in 2022 against the factory fuel pumps. The fuel pumps attach through the firewall and are secured on the inside with lock nuts that are not easy to...

The firewall has a large opening, necessary to allow the large connectors to the Rotax ECU to pass through. The included close-out plates don’t seal up the hole nearly enough so I bought an off-the-shelf firewall grommet. It comes in two pieces that join together. I riveted this to...

I consider this a big milestone, but it wound up being pretty easy to mount the engine. The engine is attached with just four rather large M10 bolts. I purchased a second-hand Harbor Freight engine crane for $100, and a new load leveler bar for $40. Not too bad,...

One minor issue with my engine was that it came from the factory fitted with an optional cooling baffle. This baffle is primarily for installation in an aircraft with a pusher prop configuration, but since my plane is tractor config, I need to remove the baffle to ensure proper...

When I bought the engine way back in December 2020, I planned to bring my plane to the airport to install the engine. I found space inside a community hangar at the Nashua airport, which I where I will perform final assembly. The hangar manager graciously allowed me to...

Last week I received the custom firewall kit I ordered to install the 915iS on my Sling 4. Shipping took a long time – almost 5 months – but I’ve read it’s a widespread issue in sea container shipping right now. Everything in the kit arrived just fine. I...

It’s been a little bit since I posted, but there are a few exciting developments to share. First, I got word that my firewall forward kit arrived in Torrance CA last week and is on its way to me! This is the long-awaiting custom kit that will allow me...

By request, here’s a breakdown of the technical and cost differences to equip my Sling 4 with a Rotax 915iS engine instead of the Rotax 914UL engine. As a quick reminder of why I’m doing this: +26HP at takeoff power (5800 RPM), +35HP at max continuous power (5500 RPM),...

My engine arrived today! This is the Rotax 915iS engine, and as I described in an earlier post, this particular engine is used with just 12 hours on the clock. Even though I bought it locally, it was inspected by Lockwood Aviation down in Florida, as they are currently...

Coming soon to my workshop: a Rotax 915iS engine! Those familiar with the Sling lineup know that the 915iS engine normally is found on the Sling TSi, not on a Sling 4. So, my airplane is going to be somewhat unique, but that’s part of what experimental aviation is...