Fuel

[Paul Davis]

Hi i'm new to this Forum, so hello i'm Paul. I have just purchased a second hand Smartech Uno with no instructions or anything. I am new to the petrol scene as an owner of 5 Tamiya vintage cars.

I was hoping that someone could give me a clue as to what fuel to put in my Smartech? I really have no clue! do I have to pre mix with oil?

Also if anyone can point me in the right direction where I could get some instructions please would be amazing.

Any hints tips or advice would be gratefully received.

Cheers Paul

 

[madmanandrewk]

Yeah you have to premix 25:1 with two-stroke oil. You can get it pretty much anywhere, the same stuff you use for weedeaters, but you need double the amount it says, so if it says "makes 1 gallon" you'll need to add two to 1 gallon of gas to get 25:1 mix.

 

[crankestein]

Its tough to say because fuel quality octane is different even if its 87. For example; 93 in CA is like 87 in LA. Different companies put additives that affect performance.

My recommendation is start w 87 and do 25:1, just buy a little, and see how it runs by the sound and spark plug color.

This considering all other are met, good compression, strong spark, clean air filter, no binding of diffs etc.

For a used engine, stick w synthetic 2 stroke oil, no cheap auto parts 2 stroke oil, or those little bottles sold at gas stations.

 

[ve7nly]

This question is sort of related to this thread so I figure I'll put it here.

I'm from the RC heli world and the gasser guys have been starting to use Coleman lantern fuel for their gasoline helicopters instead of pump gas. I guess they feel that it's more consistant in it's mixture of additives (I think it also has less additives) and it doesn't have the same gasoline smell.

So my question is, are any of you running coleman fuel in your motors?

 

[madmanandrewk]

Considering I don't have any issues as far as pump gas goes and lantern fuel is 6 or 7 times more expensive, the idea seems a bit ridiculous.

 

[ve7nly]

Oh, there was one other reason that I forgot to mention with the Coleman. No Gasoline smell!!!!! That's the big reason why I'm considering it. When I get the motor running again (or replaced) I will have to store it in the house. I live in a pretty small basement suite that has very little storage and I really don't like the smell of gas in the house.

 

[TODD]

Keep in mind that Coleman is roughly about 50 to 60 octane on the rating. Air cooled engine and really low octane fuel not going to play well together safely if pushed hard.

 

[ve7nly]

Ok, so an octane booster would probably be needed. (I've dirt bikers do that by buying cheap pump gas then adding octane booster) Not an impossibility but it would add to the cost even more.......

 

[crankestein]

The smell of weed eater in the car and in the house.

I work on a ventilated area, but still my nostrils get irritated and get bad allergies.
Use good synthetic oil, stay between 25:1 to 35:1. Until you get good on tuning.

Its a stock weed eater engine, its an overkill the extra octane. In fact it may run rough because it may not burn well. If maybe it was a high compression engine, then high octane etc would be recommended.

Before you go crazy with all the gasoline options, familiarize w the truck and engine first.

Use regular pump gas. Each engine and carb is different. What you have to do is have spare spark plugs. This is not like nitro that you check temps, its all in the plug color and sound of engine. don't get confused w all the gas stuff octane lingual.

 

[ve7nly]

Ok, thanks guys. I'm a little surprised that so many guys are starting to use it on their helicopters and yet not on the cars and trucks. I'm curious as to why many heli guys would be doing it then. Oh well. Thanks for the info.

 

[madmanandrewk]

Ok, thanks guys. I'm a little surprised that so many guys are starting to use it on their helicopters and yet not on the cars and trucks. I'm curious as to why many heli guys would be doing it then. Oh well. Thanks for the info.

I think it's a word of mouth thing. The air side of rc is just more social than the land side, especially when it comes to 1/5 scale since tracks are almost non existent, so something weird like that can spread a lot faster when fellow flyers see it in action at the field, meanwhile we're reading about it from a stranger on the internet. I'm not likely to put lantern fuel in ny $500 engine just because one person on the internet says the "heli guys are doing it". You know?

 

[ve7nly]

Well I don't blame you one bit there. I wouldn't do it because some idiot (I do include myself in that "idiot" comment) on the internet says so either. You're probably right about the word of mouth and social side of helicopters compared to the land side side though. I've visited a number of RC tracks and I'm always astonished at how quiet they are, other than the sound of rc cars racing around. You're explanation in that way makes sense. Oh, and not all of the heli guys are doing it, but it does seem to be gaining in popularity. I was wondering if the land guys were doing it as well. I guess not. Once again, I do thank you guys for the info.

 

[crankestein]

In a 4K helo rig its understandable to have it running top notch and demand only the best. For a stock engine, good heat cycle break in, synthetic oil, good mix, and a reliable source of regular 93 octane gas thats all you need. If anything, blue print the engine, remove any imperfections from the casting, some port for better air fuel mix flow.

A 2 stroke on a truck will not be running at the top of the rpm, if on a dirt bike track will be tap tap on the trigger with a wot on straight a ways. The most I have seen those 2 stroke helicopters is on YT, and its impressive how they make those engines rev for long period of times.