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Discussion Starter #1
I have not rode my bike in a few weeks due to an endless amount of life crap.

Today I take it out to run a few errands and while riding down the highway around 70ish (3000rpm in 5th) I gave it about 30-40% throttle to pass around a vehicle and thats when I heard it.

The noise echoed off the back of the forks up the windshield but was hard to hear due to wind.

Lower gears or any other RPM, I hear nothing. Poking the throttle at 3000 rpm in 4th or 5th it hits.

IMO it sounds like a few seconds of spark knock in the front head.

A touch of backstory tough. The bike has sat for 2 weeks with an empty upper tank. When I took off this morning I went and filled it up with the same fuel I have ran for several years from the same station. This is the first time I have heard the noise.

I tell you this because it may be possible that its fuel related.

My plan is to ride easy until the tank is gone and see if it continues with the next tank.

What are yalls thoughts?
 

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Discussion Starter #2
Figured id add that just a few months ago I replaced the plugs with NGK's , cleaned and oiled the K&N air filter and replaced the oil with Mobil 1, and replaced the x-case fluid..
 

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Try a different gas station and you need premium gas. I will never use a few gas stations near my house cause I noticed my bikes run like crap.
 

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Discussion Starter #6
Some of you may remember two years back I spent the summer testing fuel stations by brand, octane, and calculated fuel mileage for highway use.

I found by far the best was a BP near my house using 89 octane.

Higher octane as we all know is not more explosive but has additives to prevent pre-ignition (spark knock)..the less spark knock, the more power and better fuel economy you will have.

I noticed no difference between 89 and 93 but had a substantial loss in mileage in 87...regardless during my testing I had zero audible spark knock.

Today I went back to the station and filled up with 93. I will see if that makes a change.

Riding today I did notice I could also hear it in 3rd gear at almost exactly 3000 rpm. It still sounds like spark knock to me.

Now a side note. Somewhere around my trees or windshield I hear a small rattle, like a washer on a loose bolt. It MAY be that noise being vibrated at the frequency produced around 3000 rpm but this is speculation. The noise behind the windshield is the windshield lock lever but it only makes a noise at lower speeds and a lower RPM...

I may slip a rubber hose over the leaver to dampen the windshield lock if the higher octane does not fix the noise.

I dont care about the windshield lock noise as I know it will hurt nothing but spark knock is bad for engines.
 

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Discussion Starter #7
Well im now half a tank through the 93 octane and as far as I can tell, no more noise.

Either I got a bad tank of 89 the other week or I need to shift to 93.

If the noise comes back I will let yall know.
 

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Over here you're supposed to get 95 octane, and that is the lowest you can get.

However, people her eoften say it is better to get 98, because it often, depending on the brand, does not contain ethanol, and that gives one better mileage as a result :).

I need to give that a try some time :).
 

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Discussion Starter #9
Just put in the 4th tank of 93 and still no noise. Getting the same mileage per tank, only cost me a dollar more so I guess I will stick to 93 for now on.
 
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