XB12R Rattle noise when I get on the throttle
- Thread starter canadahippie
- Start date
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Put the best fuel in it that you have available up there. You can even try different brands. Different suppliers play with the octane numbers. I won't get into great detail, but the 'number' you see on the pump is a compilation of (2) octane ratings divided by (2). That is what the R+M/2 denotes on the sticker on the pump under the number. It stands for RESEARCH octane rating, plus MOTOR octane rating divided by two. Suppliers can and do "modify' or 'adjust' the RESEARCH number to compensate for a lower MOTOR octane number. The MOTOR octane is the TRUE unbiased rating....it is what it is. No....it probably won't hurt anything IF it is just that quick one or two pings when pulling out. It won't do it any good either, as it is two separate flame fronts colliding in the cylinder in an uncontrolled burn causing the sound you hear.....it essentially like taking a hammer and beating on top of the piston. I would do whatever I could to avoid it.
canadahippie
Member
- Joined
- Jul 14, 2014
- Messages
- 7
Thanks, next time I fill up I'll try to get a higher motor octane number. Will report back.
Hi Canadahippie! I sure didn't want to confuse you! Unfortunately, at the pump, you have NO way of knowing what the motor and research octane numbers are. And THAT is how they 'get away' with selling inferior fuels at the same PUMP number. (I/E 87,89,91,93). All you can do is try different brands or locations. I have had decent, noticeable success with Sunoco and Citgo here in the States. But....we also have 93 available to us as well. But for sure, try it and let us know! 
HI canadahippie, did you work out what caused that acceleration metallic type pinging sound. My does exactly the same when hot. Mine is an XB12s Lightning, I run race ecm, direct link, race exhaust, & hi power fuel pump. It almost sounds like gravel / ball bearings in the headers on hard acceleration, I never did work out what was the cause. (still to work it out when I get my bike back on the road from other engine work (another story)
Cooter
Well-known member
At least this ones only 8 years ago. Oh Man, is this the same bike with a "Loud, hammering, noise"?! the you posted on the other necro-thread?
Direct link is pretty OG and I have no idea what a "hi power fuel pump" could be. The stock unit is fine for volume and anything other than 49 psi would be unusual and pointless.
Do you run premium fuel? is it old? Show us the timing table on the Direct Link you have to tune it.
Direct link is pretty OG and I have no idea what a "hi power fuel pump" could be. The stock unit is fine for volume and anything other than 49 psi would be unusual and pointless.
Do you run premium fuel? is it old? Show us the timing table on the Direct Link you have to tune it.
