What kind of gas wont hurt my 70cc engine and works best?

[Guest]

Yep, with a 6.6:1 compression ratio, low octane is fine. I personally won't use coleman's white gas. I can't take the risk of detonation with that low octane and smell isn't an issue.

I fly RC also and often used to use 100LL octane AV gas for my engines because it didn't stink. Boy, the engines on this fuel were hard to start. AV gas is not very volatile.

 

[dave1490]

DrewD,

that's some really good info, thanks

my lead substitute question (a runover from my V-8 gearhead days) is stoopid i guess? these engines won't benefit from the "lubricating/coating/cushioning" effect?

lead was used befor unleaded,it was for lubing the valve seat,s.since then hardend seats have been used.so not need for poluting the air with lead.

 

[Herrmanator8]

ive always used premium unleaded in all our dirtbikes, quads, and in my bike. this bicause it burns cleaner and i think my vehicles deserve the best. so what if its 30 cents more per gallon for premium, you must really poor to complain about fillin' up your bike other than a car. also, never use shell gas, or atlest try not to because theyre fuel is deluted, its watered down so that they can get more out of a barrel of oil, use high quality oil thats synthetic blend or fully synthetic. use 32:1 fuel/oil ratio.

just my opinions, this is what i do and it works best for me. jon

 

[Jim H]

K**** Motors insist on synthetic oil for their motors. That stuff is pricey.

 

[rcjunkie]

The statement that premium gas burns cleaner is not accurate. It only cleans burner in high(er) compression engines. In low compression engines, high octane fuel actually can increase engine deposits because it won't ignite as completely or quickly as it would in a high(er) compression engine. In addition, high octane fuel has lower BTU content (very small difference) and theoretically gives less fuel economy with all other parameters remaining the same.

In the majority of cases, high octane fuel is a waste of money unless your engine was designed for its use and/or your regular compression engine is old and has piston deposits that cause detonation.

I also had an earlier posting about two stroke oils and demonstrated by certain parameters that synthetic oil IS NOT the best 2 stroke oil out there.

If you are concerned about lubrication under severe operating parameters such as in hot weather or extended use (45 miles up a Colorado mountain) at full throttle/high engine load then a blended oil that contains 20% degummed castor oil is SUPERIOR to any straight synthetic.

Look at Maxima 927 oil specs (flash point in particular) and compare it to ANY straight synthetic. You will see that it tolerates heat better by at least 200 deg F. http://www.maximausa.com/products/2stroke/castor927.asp

 

[salfter]

No, [Coleman fuel] has caused no problems and there are lots of people running it in lots of engines.

While mowing the lawn once, the mower ran out of gas. Rather than go fill up the jerry-can, I pulled out a can of Coleman fuel and put a pint or so into the tank. The engine (a Tecumseh of maybe 3-4 hp output) wasn't any worse for wear as far as I could tell, but I wouldn't have wanted to keep running the mower indefinitely on $4/gallon Coleman fuel when 87-octane unleaded was selling for maybe $1.25/gallon.

 

[rcjunkie]

Back in the day, older very low compression engines found on lawn mowers could be run on gas, white gas, and even straight diesel!

 

[dave1490]

I want to know what gas to mix my oil with. When I say that I mean, what should I use and shouldn't use for a healthy 70cc engine.TYPES OF GAS: regular, premium, ect.

Please give me any facts or opinion's you have or know on how to maintain a healthy engine

hello was useing hi-test then switched to low-test,hi-test had more power but low-test starts better.as for oil i started with an organic oil to seat the rings better after 300mile i switched to amsoil and i always use z-max {small engine formula} 1 oz with every tank of gas at times i run the s**t out of it 7000rpm and it,s never let me down 1000km,s and run.s like new.

 

[rcjunkie]

The reason you felt more power with hi-test fuel is because your wallet was lighter. Two possible explanations why you felt more power: 1. Engine is running too learn and engine detonates on regular octane but not on high octane fuel. 2. Engine rings finally seated while on hi-test which lead you to make this observation.

Zmax was sued by FTC for unsubstantiated claims (fraud). http://www.ftc.gov/opa/2001/02/zmax1.shtm

Amsoil or any pure synthetic oil will NOT provide you the best protection for your engine.

The ultimate engine protection can only be provided with a castor based two stroke oil such as Maxima 927 or Klotz benol. It tolerates heat two times better than Amsoil and has superior film strength and stability under load. It is what cart racers and others in the know use.

You are correct in that high octane fuels will cause hard starts in low compression engines.

 

[thatsdax]

Too high of octane can hurt performance. You are looking for the right burn rate for the motor. The more the octane, the slower the burn rate. These engines are low compression, less octane is the better Benzine to use. Enjoy the ride...