Messing with my Aprilia Cup

Previous owner of my RS250 Challenge Cup routinely used 100LL. I assume that’s what you mean by “avgas.” I’d recommend you run any high quality fuel that you can routinely get that fits your budget. It’s a pain for me to get 100LL where I live. So I either buy 5 gallon pails of Sunoco Standard at the gas station 10 miles away or I fill up at the race track when I’m there. Thankfully, both Summit Point and NJMP sell Sunoco Standard. It ain’t cheap. But it works for me. I don’t ride enough to worry about fuel costs. It gets lost in the noise relative to all my other expenses.

 

Yep, 100LL. My buddies have a hangout at a local airport. Direct sales are a non-starter but they have a work-around.

They're fans because they have bikes that might get ridden once/yr or less and 100LL lasts forever.

 

It last a while. Not forever. It’s similar to many race fuels that don’t have ethanol in that regard. There is usually a range depending on whether it’s stored “under ideal conditions” or not, and whether it’s remains unopened in its original container or not. But generally speaking, 1-2 years is usually fine if well cared for. But always read the fine print for your exact fuel.

100LL is generally more consistent than typical pump gas for automobiles. But it’s exact composition can still vary somewhat depending on the fuel supplier, geographic region and time of year. Most petrochemicals are made in batches. Depending on the fuel and the specific performance requirements, they usually have a range of acceptable values. Race fuels tend to be more stringent in terms of consistency. But that can vary also. Remember the Fresh N Lean Progrrssive Attack Performance Yamaha fuel controversy in MotoAmerica Superbike in 2023?

https://forums.13x.com/index.php?threads/fresh-and-lean-attack-using-illegal-fuel.384141/

 

I use a 50/50 mix of avgas and ethanol free 93 octane in both my bikes, a vintage Ducati single and an aircooled Rotax single.

I have been told that neat avgas burns slower and therefore doesn't produce the same power as gasoline of the same octane rating, don't know how true this is.

I can get it easily from the local airport where I can drive straight up to the pump and pay by card.

 

Av-Gas or 100LL is perfect for any machine without an O2 sensor.
It's just pure leaded fuel, no bullshit, regulated, tested and checked along with the holding tanks
every 6 months, up to a year for remote locations, worldwide.
They say 3-5 years stored properly in normal climate..
Round here (Mid-Atl), NAPA's and Southern States Co-Ops carry Sunoco and/or VP.

 

Engine in last night. I think I have all the parts I need to make some noise. Planning to start it on pre-mix with the oil lines disconnected to make sure the pump is working.

I was happy to find that the engine cradle fit almost perfectly. Just a light nudge to make a few holes line up. It was way off after the initial welding because I didn't leave the frame with the fabricator.

 

Change your coolant kids.



Might make some noise today.