Ran Regular gas now it back fires

[Doddy]

My Friend bought a Banshee and didn't know that you had to run 92 Octane so he ran it on Regular 87. Now it hard starts, and back fires after it gets warm and then dies. When you get it running it does alright at first and then falls on it's face and won't start again.

 

What are the possible issues that can arise when you run to low of an octane fuel?

 

Thanks,

[SAVAGE420]

 

 

What are the possible issues that can arise when you run to low of an octane fuel?

 

Thanks,

 

KA-BOOM ....Detonation my friend. Do a compression test on the motor with a compression gauge. THAT will tell you what fuel he needs to run...not what the dude said to run.

Edited August 31, 2009 by savage420

[Doddy]

I'm pretty sure that detonation occurred...and if it did what does that mean? New top end (piston, rings, head)?

[AKheathen]

yup, exactly. do a compression test and then pull the head and visually inspect. any other mods, like removing the airbox lid/snorkle. running low octane once might not do much harm, if it's ridden easy, but it does sound like it did detonate from the symptoms. he might be lucky, too, and just have water and crud from the cheap gas messin the carbs up. what premix/ratio?

[Doddy]

yup, exactly. do a compression test and then pull the head and visually inspect. any other mods, like removing the airbox lid/snorkle. running low octane once might not do much harm, if it's ridden easy, but it does sound like it did detonate from the symptoms. he might be lucky, too, and just have water and crud from the cheap gas messin the carbs up. what premix/ratio?

 

The Bike is bone stock except for it has pods with the air box removed and stock pipes. I told him to run Yamalube Type S (or R, which ever has the banshee on the bottle I can't remember) with a 24:1 ratio. We took it out last weekend and they ran about 4-5 gallons through and then we took it out this weekend and went through another 3 before it started fucking up. When it started stalling out and backfiring I asked him if he mixed it right with premium and 24:1 and he told me that he just got regular and ran a 24:1 ratio.

 

We immediately drained the gas and put premium in it but I think the damage is done. We pulled the carbs off and cleaned them up and it seems to be running alright but I can't really take it for a test ride on the street.

 

When I put premium in it at the sand it would start up and seem to be running alright and then when I would get it hot and run through a few gears it would fall on it's face, start back firing really bad, die and I couldn't get it started until it would cool. It has 250 mains in it right now with a 25 pilot, it could be the jetting but I don't know.

[AKheathen]

i would go get the $12 head gasket and some fresh coolant, and pop the top. 3 tanks is a bit much. the jetting is possible, but you need to check the topend anyway before you chase your tail.

[Doddy]

I would say 5-7 gallons max, and compression is 124 in both cylinders. starts up and no hesitation like before now that the regular is out of it, but have not ridden through gears.