What grade of gas is an Ironhead supposed to run on?

The reason I ask that the engine seemed to run rough and the exhaust was popping and leaking through the cylinders where the pipes go in. I guess the exaust gases where ingiting? I shut it down and tried to figure out why is was running like that since it ran fine last time. Then I remembered that I refueled with 93 octane after I shut down last time. So I went to the gas station and got some 87 octane and put it in. It sputtered and popped again and then cleared up. So I assume the gas I put in last time had something to do with it.

 

If it has stock compression, ignition, etc. it'll take the 93 octane. I wouldn't run the 87 or 89 stuff; while it may do OK most of the time, it'll prolly start pinging under load. Sounds like you got a bit of bad gas, or maybe some crap in it.

 

I was thinking the same thing which is why I put 93 in. Then when I fired it up today, it it kept popping like it was going to blow a headgasket or something because smoke was comming out with each pop. I hope it was just bad gas. Is there anything else that would cause that?

 

try to buy gas from a high traffic station they refill their tanks more often and the chance of getting bad gas are far less.

good luck by the way!

 

it depends on compression. if your bike runs fine on 87 or 89 but like crap on 93. i would say the 93 is causing a rich condition so unburnt fuel is igniting outside of the combustion chambers. check your plugs if they are black then the added octane is the problem.

 

93 octane? Can't say as I have ever heard of it. You wouldn't be meaning to say 91 octane...would you?

 

nope lots of places have 93 octane unleaded for sale.

 

Depending where you are, premium is anywhere from 91 to 93 octane, and sometimes even lower at high altitudes.

 

The last time I had an engine act like that it was due to water in the fuel. If you refueled and let it sit over night the suspended fuel droplets would have fallen to the bottom tof the tank overnight. Pull your filter and have a look. You can sling the extra fuel of of the filter onto a flat smooth surface and any water will appear as droplets. If this is what you have then a complete system clean out will be needed. Including the carb to prevent future problems. Good luck.