What do you know about octanes?

[Musick17]

I wanna know what you know... because I dont know!

Ive got an old 79 suzuki 370 street legal dirt bike. I had it running and everything. Then I changed the oil and put new gas in it. Its the proper oil but I put really high octane gas in it. and now it wont start. think that would do it?

 

[adsm08]

Might.

Octane is the fuel's resistance to burning. The higher the rating the more heat/pressure it takes to get the fuel burning. If you went overboard on the octane (most bikes do like ~92) you may have a problem with the ignition system.

 

[wlabrum]

My guess is when you drained the old gas out you stirred up sediment in the tank. First off plug the plug clean it. With it out lay it on the head with the plug wire hooked up and see if ya have spark. the plug will tell ya what ya need to know....if its wet ya have no spark if its dry ya have no fuel. it would also a good idea to pull the float bowl of the carburetor and clean both it and the carb with carb cleaner

 

[Musick17]

I guess I should be more specific. First thing I did when i got it was pull the carb and cleaned it. Ive done quite a few carbs so its good to go. I put a fuel filter in line in case things got stirred up, so nothing should have gotten back into the carb. I took the petcock off and cleared all of it out. I changed the oil with the recommended 10w40. I put a new air filter on it. new spark plug. Ive already pulled it and grounded it out on the frame and I have spark. gas is getting to the carb. So the only thing i can think it would be is the newer high octane gas, which i did add sea foam too.

Just crazy cause i had it idling/running fine before I put the new gas in and changed the oil.

Maddness i tell you.

 

[wlabrum]

I guess I should be more specific. First thing I did when i got it was pull the carb and cleaned it. Ive done quite a few carbs so its good to go. I put a fuel filter in line in case things got stirred up, so nothing should have gotten back into the carb. I took the petcock off and cleared all of it out. I changed the oil with the recommended 10w40. I put a new air filter on it. new spark plug. Ive already pulled it and grounded it out on the frame and I have spark. gas is getting to the carb. So the only thing i can think it would be is the newer high octane gas, which i did add sea foam too.

Just crazy cause i had it idling/running fine before I put the new gas in and changed the oil.

Maddness i tell you.

How much sea-foam did you put in a 1 can treats about 20 gallons and by it self is not that flammable. as it takes three things for combustion
1. spark
2. fuel
3. compression

I would drain the fuel out of the tank and carb go get a gallon of 88 octane and poor it in.
another thing to check as i am assuming this bike is a 1 cylinder is to make sure the compression release is closing.

 

[RustedRanger]

Not trying to be a nit picker but octane is resistance to detonation.

 

[hopster]

octane is the resistance to burning. because of that higher octane fuel resists detonation. which is caused by high temps that come with higher compresion.so that combined with seafoam might cause this.

 

[GoodOld85BlueBalls]

Ok, Octane. The lower the BTU of a fuel the higher the octane, the higher the BTU of a fuel the lower the octane and it is the higher BTU that makes the fuel more likely to cause detonation, and the lack of octane that can cause a engine to knock (Known as pre-ignition or autoignition). Therefore Higher Octane fuels won't always make more power and can make a vehicle with low compression pistons run worse and be harder to start due to the lower BTU of the fuel. Most modern engines do let you have a noticeable difference in the fuel you run as its management system will adjust to the octane/BTU of the fuel you are running. Race engines obviously need the high octane to stop them from coming apart,(high compression/RPM) not to just make them run better.

 

[alwaysFlOoReD]

Higher number octane = slower burning of fuel. Don't know about your problem though.

Richard

 

[RustedRanger]

Noun 1. octane rating- a measure of the anti-knock properties of gasoline........ "Knocking" is when the gasoline explodes,exploding and burning are two different things.

 

[FroLock84]

I wanna know what you know... because I dont know!

Ive got an old 79 suzuki 370 street legal dirt bike. I had it running and everything. Then I changed the oil and put new
HID Bulbs gas in it. Its the proper oil but I put really high octane gas in it. and now it wont start. think that would do it?

Yea if you put in too high of an octane gas then it will cause it not to start. Just drain it out and put in lower octane gas and you'll be good.

 

[Musick17]

Thanks for all the input guys! I have drained the gas and lines and carb and put in some 87 octane. Still no fire.....

And im actually trying to sell it now. But ide still like to have it running when someone comes to look at it. the plug looks fouled but still sparks across the gap? so im gonna replace that too. for 3 bucks it cant hurt...

 

[Beef52751]

did the filter already plug in the line???is it getting gas in the carb??? does it have compression???
That is what i would check first

 

[Musick17]

Its got compression, the carb is getting gas, and the line did not have an inline filter. I added it. It should not constrict the gas flow enough to make a difference.

 

[Musick17]

But a guy called me today and said he would buy it for the $400 i posted. and heck, i onnly have $150 in it. so im not complaining.