So I got out and put some miles on today , and I noticed that running 55-70+ mph in 5th gear when I get on it to pass , catch up, go up a grade ,and so on it pings to various degrees. 91 pump fuel is the highest level we have anywhere in the state. That's what I run . Engine is a mystery other than it has sock heads and an s&s E carb . I know it's been gone through at the dealer 6500 mi ago but what ever cam and possible port work wasn't changed. So my simple solution is octane booster and carry a bottle along. Anyone else done this or had similar issues. Bike is 96 flht with 80 inch evo stock case jugs and heads as far as I know. I assume the dealer put stock pistons in it but who knows. Or is there a way to adjust the timing? I hate to do that tho cause I get close to 46 mpg right now and we all know that having to stop more often isn't a good mod. Thanks for any help. Ps I could barely notice is but kept hearing a funny tone then when I put my head down out of the wind it's plain as day the pinging.

 

Old gas? Get some VP or Cam II dump in it. See if knock is goes away, then if it comes back on 91 then you're going to need to carry booster with you.

 

With an S&S carb already installed I'd check what ignition the bike's currently running. Is the "points" cover on the right hand cam chest cone still riveted on (from the factory,) or are those rivets now screws?

 

I would take a bet that you have carbon in the combustion chamber. Install top tier premium fuel and 5 oz's of Chevron Techron fuel system cleaner concentrate. Run out on the highway hard and hot, shut it down hot and let set overnight. Repeat again, it will likely stop pinging. This product works. Let us know what results you get.

 

Ok I'm going to sound like an idiot. Do you have a pic of the cover you're talking about? The coil is stock hd motor co Inc with 8.8 acell wires . Has 2410p acell plugs in it . Don't know if maybe I can go colder plug . Any way I don't know a lot about the electronic or even mechanical of a harley I'm an international diesel tech by trade .


And both tanks of gas did it one from shell and the next from kwik trip in two different cities 180 mi apart.



I suppose it could have some carbon but I'd think 6500 mi after a rebuild it shouldn't be. I know the guy and he's not a granny rider lol it was run like I ride there are 90 + mpH rips ever ride but it gets maintenance regularly.

 

If you mean this little guy yeah its been in to lol if not then I don't know what I'm missing with riveted cover.

 

The only input that I have is MOST octane boost does nothing but raise octane a half of a point, which isn't crap, you will need to retard the timing a bit to really deal with this the right way.

 

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My 09 w-stock 96" also detonated on hd's rec 91 octane fuel esp in warmer temp and this is what i did that stopped it.

* 1st is if you havent already done so install an aftermarket crankcase breather to remove all the overheated oil mist laden crankcase gases from being injested by the motor that increases comb chamber temp along with also causing excessive carbon buildup that increases compression & hotspots of carbon in comb chambers all of which increase the motors tendency to detonate.

* 2nd,Next run a healthy dose of 1.5 oz per gal of fuel (not 1oz per gal fuel because i found that ratio isn't as effective at removing excessive carbon buildup) of chevrons Techron injector & carbon/combustion chamber cleaner thru a few tanks of fuel to remove excessive carbon buildup from the comb chambers and pistons along with cleaning up the carb & or fuel injectors at the same time too.

* 3rd,lastly is air cooled motorcycle motors tend to detonate more as they heat up and i found my 09's 96" would detonate more as oil & engine temp increased as the outside air temp increased.

So to corrected that by installing 2 cooling mods that reduced oil temp 50deg f which were ultra cools oil cooler with twin thermostatically controlled elec cooling fans along with Wards cooling fans both at the same time which is key!

Installing the 2 cooling mods at the same time basically stopped the detonation my bike had in warmer temp under load .

But i also did the Techron clean as i stated above along with installing DK's external crankcase breather on my bike too because all 3 of those things are important to correct & or get under control in stopping detonation or at the very least significantly reducing the detonation your HD's experiencing.

BTW,i generally dont rec having timing backed off/retarded to stop detonation (though it can reduce it some cases) because it not only reduces pwr & trq a bit along with making throttle response less crisp it also reduced fuel mileage and can increase engine temp a bit too.

And increasing engine temp can do guess what,increase the chance of the motor detonating which is what your trying to get rid of in the 1st place.

Thats why i rec going after and correcting the root causes of the detonation in the 1st place so you wont loose any pwr and will likely pick up a little umph with carbon being cleaned from motor and hot crankcases gases being removed from motors intake too along with making the oil run 50deg f cooler too.

And also remember the oil cools the motor too so the motor is running cooler when the oils running 50deg f cooler with the 2 cooling mods i rec.

Afterthought,should also have the bike/motor dyno'd to check AFR to ensure its not running too lean which can increase engine & comb chamber temp which also increases the motors tendency to detonate too so if its running too lean in any area of the fuel curve they can fatten up the ARF as required/where need be.

Good Luck.

Scott

 

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Thats right that most octane boosters you buy over the counter only inc octane by 10th's of a pt and not even 1 full octane pt.

But that's accept for this product that flat out works because its the real deal lead!

OCTANE SUPREME 130 octane booster thats the same exact real lead they used to increase octane in pump fuel in the 60's like for example Sunoco's 260 that was approx 101-102 octane.

Isnt cheap but when you do the math it's still cheaper then race fuel .

See link below for details.

BTW,i have been using this product for 2+ decades with great results in the 60's muscle cars i wrench for other people along with my own 69 chevelle ss 396 w-M20 Muncie & 12 bolt posi i bought off the original owners family in 1978.

Note,its only safe to use in carb'd non EFI apps because over time the lead can foul 02's and cat converters leading to runability & emission issues too.

Scott

http://www.wildbillscorvette.com/OctaneSupreme01.htm

 

Your bike shouldn't ping! It is quite probably a victim of the classic home Harley PO tuner who has put an S&S carb on it and never sorted that out, nor optimised the tuning of his bike. That has been going on since before I bought my first Harley in the 1970s and continues to this day with EFI bikes. 'Twas ever thus! You don't need an octane booster.

If your bike still has the stock ignition module I suggest you change that for an aftermarket one, to get the benefit of much better advance curves, then if necessary get a local indy to tune your bike properly for you. You will be surprised how much better it can run!