We are relatively new to the karting world and purchased a used Jr Sportsman kart which we’ve recently gone over and gotten on track. The previous owner ran a castor mix although he really had no reason why he had chosen castor. After reading up on forums and different articles we have decided to switch to a synthetic and chose Redline. After additional reading it looks like 16:1 is the ratio we want to go with (please let me know if am way off here).
My question is should I drain the remaining castor based fuel in the tank and then refill it with the new Redline based fuel or is it ok to run the current fuel down to say a 1/4 tank and then fill it up with the Redline mix ?
I’ve run Yamahas for many years. I’ve used castor, synthetic and combinations of the two. I ran the last 8 or 9 years on redline. It’s a good oil. Everybody has their opinion. As for whats in your tank, run it down low and then pour the new redline mix in on top. It will be fine.
<p>Another vote for Motul 2 stroke oil. Please do NOT leave the fuel/oil mix in the tank on your kart. Only mix as much as you need for the day and drain it after the race weekend. Keep in proper gas can and shake it up good, before pouring it back in the tank for the next race day. Synthetic oils stay suspended in fuel a lot longer than castor oils do, but if you leave it in the tank for weeks, chances are, some of the oil will drop to the bottom resulting in poor running of the engine, you get the picture.</p>
Thank you all for the replies. I’m checking with the club to see if they have any rules on what fuel mixture is required. A quick scan of the rules on the website doesn’t make any mention but i want to be sure.
We are down well below a 1/4 tank sounds like I should be fine just filling it up with the new mix this weekend. never though about letting it sit in the tank so that is good to know as well.
Red Line is a great choice. I’ve been using it for years and have never stuck an engine. 16:1 is the right ratio for your set up. I would dump the remaining fuel just to inspect the bottom of the tank plus you want to get your needle settings with a know mix.
FAA certified jet engine and aircraft technician,
Nicholson Speedway class champion 2001,
Yamaha KT100 Service Center,
41 years karting experience