is it true you can run a 12:1 hc piston on pump gas?

[NOS_350X]

Be safe, get the 10.25:1. When you decide you want a little more and will pay the money for the racegas then step it up to the 12:1.

Ninja, what are the specs on the cam, or grind number (even if its custom they give it a number) Did you degree it in so its set properly? or just "thow in and go." How did you decide how you wanted it ground? Why would you have to grind the rockerbox? valves are only so long, no way the rockers could hit??? I can understand the guides being shortend for extremely high lift cams. Who did your porting? they match it to your custom cam?

With all that work you say you have done i coudnt imagine running it on pump gas. To not ping is amazing unless your cam isnt set right and killing your compression.

[wizzard]

Try to get a kit (piston, cam etc.) matched for your bike. The same 12.1 piston will give you different readings when you do a compression check, as you change cams. (If cam "A" opens the valve sooner than cam "B", your compression will be less with cam "A"). Also, you may want to get a stronger connecting rod, the stock types usually fail me.

[SWIGIN]

my 1 year old 85 200x ( back in 86) had a 12 to 1 piston and thats it...every thing else was stock exept for the kerker exhaust and it needed at least 110 oct.

even with that it would still ping on real hot days....now with a nice aftermarket cam to bleed off some of the cly pressure you might be fine with 93oct.

[NINJA]

Your post is funny to me, because you are trying to call me out. Well guess what? I'll answer and prove to you, because I don't bulls**t! Please, allow me to retort This is a Web grind 213 for 86-87 200X. It's a cam they used to grind for Powroll. I had it done back in Aug. of 02. Of course I couldn't degree it when I installed because the 86-87s had a pressed on sprocket and Web welds them once installed. It was also their instructions to relieve the rocker box. The pics will speak for themselves. I do my own porting and bowl blending and have been for a few years now. However, I am not going to give away my specs. Do your own homework and stop pissing me off!

[wizzard]

"I do my own porting and bowl blending ..."
What's bowl bending ?

[NINJA]

I'm done......

[Dirtcrasher]

"I do my own porting and bowl blending ..."
What's bowl bending ?

Bowl "bending" is when you install a carb thats too big for your machine. You smash in a corner for clearance and it's called "Bowl Bending"

[NINJA]

Now that's funny DC!

[wizzard]

guess a funny answer is better than none.