What 2 stroke oil are you guys using in your 2.5 efi race motors? Also what mixture are you running? Thanks, Tom

ttt.

I have used Mercury racing oil, mixed at 40 to 1 in all my 2.5 EFI'S and have never had a problem.

amsoil synth @ 50/1 for me... they seem to like that

I run Merc racing oil 40 to 1. I however have blown at least 5 powerheads over the years. I have owned about ten 2.5's in the last few years. They are a lot of fun and not real reliable. They are high rpm race engines.

Brad , what are you finding that is blowing them up? The motors I have are 2.5 280 race offshore efi's.We are in the process of rebuilding one powerhead that had 2 bad pistons. I bought the boat with one bad motor. 2000 30 ft Motion , Tom

Head gasket failures is one. Needle bearing failures is another.After a while the needles "skid" or "chatter" instead of rolling .Usually on crank end.Not too many wrist pin bearing failures.Overheat or lean is one, usually piston 1 or 5.My recomendation,bearings,rings,gaskets,seals,oil pump and stator/switch boxes every year.

From 1993-2000 I ran a twin 2.5 carb (245 hp) powered Talon 22. Added 110 hp Nitrox nitrous oxide system to each engine and started using Maxima castor 927 oil. Never had an oil related failure and put 230 hours on the engines. Expensive oil, but very high quality. Burns very clean and has a really unique smell (like the little RC plane engines). My engines turned 8800 rpm on the bottle. It was scary fast...

http://www.maximausa.com/products/2stroke/castor927.asp

klotz is a very good 2 stroke synthetic oil, mixed @40-50 to 1. beleive it or not yamaha 2 stroke is very good as well. when you take one apart that has been using these 2 oil's the back of the piston, is very clean indicating a cleaner burn. this relates to better lubrication in vital areas as stated above due to lower combustion temps on the other side of the piston.

at least in my observations.

thanks guys for the info. Tom