I mentioned in my last post that Donna kayaked the Salt River again with her friend Audrey on Friday. This time, instead of taking our two-seat Sea Eagle 370, she used one of Audrey’s single-seat Sea Eagle 330s.

Here are a few pictures from their trip down the river. They started near Saguaro Ranch below Saguaro Lake and pulled out at Granite Reef four and a half hours later.

Also, I mentioned rain moving in Friday night. There were scattered thundershowers in the area while we had the J Street potluck. We got lucky and the thundershowers stayed to the north and east of us. At one point there was virga in the east – virga is rain falling in the sky that evaporates before it reaches the ground.

The virga created a rainbow. It rose from the right and arced in a quarter circle. It disappeared before I could shoot a photo. Then it re-appeared in a mirror image arcing down to the left.

My project for Saturday was servicing the Spyder. I needed to change the engine oil and filter and the hydraulic control module (HCM) filter. The engine oil in the Spyder also lubricates the transmission and operates the hydraulic shift mechanism. The first task was removal of the plastic body parts – known as the tupperware.

The Rotax 998cc V-Twin engine in the Spyder has a dry sump lubrication system. Most automobile and motorcycle engines are a wet sump type. Wet sump means there’s an oil pan below the crankcase containing the oil supply for the engine. A pick-up tube in the pan delivers the oil to the oil pump where it’s sent through the engine under pressure.

A dry sump system is commonly found on race cars where it offers certain advantages. In a dry sump system, there isn’t an oil pan below the crankcase, there’s a remote oil tank instead. Two oil pumps are used – one to scavenge the oil out of the crankcase after it has circulated through the engine. The oil is then pumped to the remote reservoir. A second oil pump delivers the oil from the reservoir to the engine where it circulates throughout the lubrication system.

Dry sump systems are more complicated and also have certain requirements for checking the oil level correctly. The reason the Rotax engine uses a dry sump is primarily a packaging advantage. The 60-degree V-twin engine is compact front to rear but it’s a tall engine. Taking away the oil pan from the bottom of the engine reduces the height, allowing it to sit lower in the frame.

Race cars use dry sumps for a number of reasons. They reduce power loss from drag that the oil in the sump can create as the crankshaft spins through it. It also takes away the chance of the oil pick-up drawing air as the oil sloshes around in the oil pan through high G-force loading in turns or with braking and accelerating.

On the Spyder, the dry sump meant I had to drain the oil reservoir, then remove a second drain plug on the crankcase to make sure it was fully drained. When you shut down the engine, the pump in the crankcase no longer pumps oil back to the reservoir. The oil in the engine lubrication system slowly drains to the bottom of the crankcase. I estimate nearly a quart of oil came out of the crankcase drain. On start-up, the scavenge pump in the crankcase would quickly pump that oil back to the reservoir. Here’s a photo showing the remote oil reservoir – it’s poorly focused but I didn’t notice that until I had the body panels put on again.

I had one problem. The HCM filter for our Spyder could be one of two different part numbers. I never had it apart before, so I didn’t know if we had the short filter or the longer one. The replacement filter I had was the longer one. It turned out I needed the short one. I’ll have to get another filter and take the body panels off again to change the HCM filter.

When I was finishing up, Donna was preparing to drive her rental car to a hair stylist in Tempe. She opened the big basement door on the passenger side of the coach and found oil on the nylon bag that holds our windshield cover. Lots of oil. I looked at it and saw it was hydraulic fluid. There are hydraulic lines and an accumulator for the HWH leveling jacks and slide out rams on the top of the compartment. I looked for leaks around the area where the nylon bag was stored but couldn’t find any.

I put a strip of paper towels under the hydraulic lines so I could see if it dripped. The drops on the paper towels would provide a clue where to look for a leak. I checked several times all afternoon and into the night. No drips. I checked again this morning. No drips. Where the hydraulic fluid came from is still a mystery at this point.

We have rain in the forecast today. I heard a few drops already as I typed this. I plan to hang out and watch the Moto GP race – I’ll also watch the Moto 2 and Moto America races. Donna is planning to do some shopping.

By the way – congratulations to the Detroit Red Wings for making the Stanley Cup Playoffs for the 25th consecutive year. That’s right – they’ve made the playoffs every year since 1991!