Piston question

[armysig]

What is the stock pistion compression rated at? I'm looking to go with more compression but I don't know what the stock specs are. I do not want to do any thing bigger as far as 416 and up. I want to stay with a stock size piston.

[400exrider707]

Stock is in the neighborhood of 9.1:1 stock, I would do an 11:1 personally.:o

[Chino886]

It sounds like you are trying to combine 2 different variables here....

You have Compression and also Bore size.....

You can get different bores with different compression ratios....

You can increase compression without boring it but most people go ahead and bore it while they have it apart....I wish I would have.....

[armysig]

Thanks on the specs.

Chino I am not boring out my engine. I just wanted to put in a piston that has more compression. I don't have the funds to do a complete engine rebuild.

So I figured I would go with a Stage 2 hotcam and more compression.

[Chino886]

Hey armysig, the cost of a 416 hi-comp piston and stock bore hi-comp piston are the same, it will only cost you $30 more for the bore of the sleeve.

Everything else costs the same......gaskets and what not......

[armysig]

True, but then i'm looking at the cost of having the engine bored out and if i can't find a good shop in town i'll need to ship it out. It's just a cost that I can't afford right now.

Plus I want to keep some things fairly stock on the bike. Simple things like switching out parts and stuff is fine for me at the moment.

[Chino886]

I can respect that, but I just wanted to let you know ahead of time, I am sitting in the same position that you are in right now, stock bore, hi-comp piston, cam, carb......the works!

NOW I NEED MORE..........:devil:

Don't get me wrong, it rips, but you can never have enough ponies.....

[BLEEDRED]

Hang on a second. Listen to Chino. Before you take the time to tear everything down you should really consider changing the bore if more power is what you are after. The cost is minimal. There are plenty of good shops you can ship your cylinder to for machine work. The cost is very reasonable. Just my $.02. Good luck.

[armysig]

Well to be honest, I'm not good enough on the track yet to warrant me to have a built up quad. That would be like giving a 10 year old go cart kid a Nascar stock car. All you would see is a spot on the track.

I'm fine with the small mods I'm making. It's just getting me ready for when I can buy a bigger quad next year or the year after.

[BLEEDRED]

That's cool man. I would encourage you to consider spending your money elsewhere. Possibly on suspension then. To me it's not worth tearing the engine apart if you are not looking for more power. You're going to get deep in little parts, gaskets, o-rings and what not's. And just for the record, increasing the compression will be giving you more power.

[armysig]

yep. I'm looking for a little bit more power. But not to the extent that I wouldn't be able to control it. I found out this last week end at a race that I was doing great but I just didn't have the little umpf needed to clear a few jumps. Not that my quad coudn't do it, and I did, I just want to feel a little more comfortable out there.

I have suspension. My Sig says what I have. I'm sending it out to GT thunder to have my shocks revalved and sprung this week. So It should handle a little better once Laz is done with it.

[BLEEDRED]

I understand. I just noticed the suspension that you have. Rock on!!