56 FSa/ 81 FSa Fuel nitro advice

[Kevin Moore]

Been away from this hobby for some 20 yrs ( thought it was less but doesn't life fly by ) spent the last month or so getting out with a trainer and OS 46 LA trying to regain some lost or forgotten skills. All going better than planned and plenty of smooth landings.

So whilst some spare cash is around Iv'e bought a Kyosho Calmato 60 sport and a Hangar 9 Pulse xt in readiness for moving on from the trainer and eventually decided on the OS 81 FSa for the Kyosho and the OS 56 FSa for the pulse.

Over the next few weeks I'm going to get both of these motors run in and fitted into the appropriate models intending to fly the Kyosho first. Both the OS manuals advice about fuels is similar and say the engines leave the factory timed for around 15% nitro in obviously unamed fuel brand but containing min 18% oil. I decided to go with Model technics formula Irvine but although my local shop sells this they thought that 15% nitro was way too much yet the OS manual say engine should be happy with 5-20% nitro.

 Would appreciate any thoughts on this and also if I do end up on 5% nitro how big a change will this mean to the engines current settings as set by OS.

One other point, Iv'e never used four strokes before but opted to go this route for a few reasons, one being noise and also I intend to use OS flexible exhaust pipes so I can route the silencer in a better place to keep as much of the crud off the fus as I fly off sand a lot and cleaning is a real pain.

 Would appreciate any help or input many thanks

[Former Member]

[This posting has been removed]

[Ernie]

Hi Kevin,

Everyone, but everyone has an opinion on fuels.  Look at the Just Engines web site, and, there is an excellent article on the home page, that just about says it all

As far as I'm concerned, I don't want to be changing brews for each engine, so I go for 10% nitro and synthetic oil for everything. I find it makes running the infernal things easier......But I do just love the smell of castor

ernie

[David Martin 2]

I don't fly the cheapest fuel on the go Kevin, but I've run Coolpower 10% (about £15 a US gallon at my door) for the last 8 years through every engine I own from the Enya 049 2 stroke to the Laser 120 4 stroke and have very consistent runs with clean engines. My OS's love the stuff and I think you'll find the factory settings are set rich anyway (just right for the initial runs) and you'll soon be tweaking them in after a while.

Coolpower 10% contains 18% lubricant and 10% nitro, just what is recommended on the pamphlet with my OS 55AX. 4 stroke specific fuel has a little less oil content, but a top show pilot told me that Coolpower would be ok to use in them and so far has been proven right..

Everyone has their favourites though Kevin and there's been many a heated discussion on forums over it too..! I like the fact that I only have the one fuel to buy and use at the field, whichever model I'm running on the day. A postal batch of 4 US gallons lasts me about 3-4 months usually. 

Good luck.

[Chris Dickens]

Kevin

As everybody else is saying, fuel choice is a very personal thing and 100 modellers will give you at least 50 different replies!

You say you are going to go with Formula Irvine from Model Technics, I have used the Contest 10 (10% nitro) in all my motors both two and four stroke, both fixed wing and heli, for at least 5 years with absolutly no problems.

Hope that helps a little

Chris

[Richard Hansford]

Kevin.

Model Technics' Propower 10% Nitro is excellent and will run cleaner than Formula Irvine Contest 10.  Propower has the 18% oil content that OS specify for warranty.

Regarding the nitro level be aware that nitro content can be by weight or volume.  You get less of the expensive nitro in your fuel if the blend is by weight because nitro is relatively heavy.  Roughly speaking a fuel with 15% nitro by weight has the same ammount of nitro as 10% nitro by volume.  American fuels are often blended by weight and I suspect that the OS specification reflects that also.  The Model Technics fuels are blended by volume  so 10% nitro Propower matches 15% American fuel.

Enjoy your return to flying.

Richard