Well, I found out what was making the car ping. The car is always tuned (I'm ****).
I have 4x 720cc and there should be no reason for running lean. I have been using pre-mix for the past 4 years now and I don't drive it as often as I used to (that may have been the problem). The car sits for 2 weeks sometimes until the day is nice and clear for some speed runs. Anyway, I *think* having the car sit may have clogged the injectors somewhat (2 stroke oil is somewhat sticky). I had the 4 injectors cleaned/ balanced to within a couple cc apart . 2 of 4 injectors were borderline. Now there is no hint of pinging even at high boost. So, those who don't drive the car often and running pre-mix, should regularly run REDLINE SL1 once in awhile or have your injectors cleaned (by a pro) if you haven't done so AND run REDLINE SL1 once in a awhile which I plan to do. Your heart skips a beat when it pings at 7000 rpm.
Anyway, this is FYI.

 

You checked your fuel filter?
My car bucks at 2kRPM and runs lean on top - I don't boost anymore cause the EGT's get too high. :P

I just haven't gotten around to changing the fuel filter and getting the injectors cleaned at Auto Pro.
You got them cleaned over there???
What were the numbers???


-Ted

 

Can someone explain to me what exactly 'pinging' is? Ive seen this term used but Im not sure of it's meaning.

Thanks.

 

The air/fuel ignites before it's supposed to. Very bad.
Sounds like shaking a few marbles in a coffee can.

 

Yea, I changed everything that's fuel related ..EVERYTHING. The only thing that came down to was the injectors. Even though I use *ONLY* SHELL and CHEVRON premium, I think the 2 stroke sticky residue somewhat cloggs the injectors when I don't drive it every so often. Sometimes it sits for 2 weeks.
I had it done at AutoPro.. ask for Paul. He's pretty quick...about 2 hours.
New o-rings, pintle caps. All for $25 each and you don't have to wait 1- 2 weeks to send it to the mainland + FEDEX shipping.
I forget what the numbers were but really close to all 4 injectors.
I think Larry's NAPA in Kaimuki does it .

 

that redline cleaner was good stuff...my father threw a bottle into the tank in his buick and the next time he had the filter off of the throttle body he noticed that it was all cleaned out. he does most of his own minor work on the car so he notices things like that .

as for autopro...last time i was there i got injectors cleaned for 20 bucks each o.O

 

Yea, now it's $25. Still cheap though.
REDLINE and BG is good. I have a few cans of BG that I'll use monthly.

 

Sure, the two-stroke is sticky coming out of the bottle, but you've got to remember gasoline is basically a solvent- if you rub the gas/premix mixture between your fingers, you're not going to feel anything remotely sticky (unless you're premixing at a 20:1 ratio or something crazy).

What I'm getting at, is if you let the car sit for long periods, the gas varnishing up is going to do more damage than the premix ever will...

 

had a premixing friend fire up his car after 2 years of sitting (after replacing battery and alt and tweaking all his controllers) and go to a gas station, top off, put in some of the 2 yr old premix that was sitting in the car, and then drive 300 miles to ship the car back home. his fuel system is kind of clogged though and his injectors probably need cleaning, but the car made the trip without a hitch

 

Yeah, I think the two years sitting is the culprit. :P


-Ted

 

I know that. But, there must be some residue that accumulates on the screen and internals after many many hours of use without an injector cleaning solvent. If the car isn't driven every so often and it sits, I think even more so. It sure can't be the fuel since I use only SHELL and CHEVRON premium. I change fuel filter (OEM) every 6 months.
After thinking about it, it has to be premixing. There's no hard evidence , just speculation.

 

dirt bikes run premix all day long, i have pulled apart carburetors and they are as clean as non premix carburetors after years of service, premixing does not clog up orifices or screens(the bikes have screened filters and tiny jet orifices that can easily clog up), keep in mind these bikes see 20:1 to 50:1 ratios also which is fractionally less than premixing your 7.

throw the speculation out the window please.