11:1 stock bore with hot cam questions!!

[TEEGUNN]

I have been considering doing this to my 400ex. I have a WB e series slip on, K&N jet kit, K&N filter/outerwears sleeve and 8 one inch holes in my airbox lid with the snap in foam/plastic plugs in the holes. I also have the WB rev kit, which I doubt I need anyway. So how much HP gains can I expect from just adding an 11:1 piston and a hotcam (2?)? I don't really want to drop too much into this machine right now. How much will this cost me? Also, will I need to use race gas with the 11:1 piston? What about reliability factors or anything else negative? Lot's of questions I guess, but I don't want to GUESS concering my decision!!:D

[2qk4u]

well i have the 11:1 standard bore piston and it cost me a whopping $120 for everything to do it. i do recommend that you use a honda head gasket instead of the cometic crap they give you with the wiseco kit. iam getting ready to drop a hotcams 2 in mine after xmas and hopefully that will wake her up some. the piston alone helped her a lot. roughly $139 for the cam i believe. well good luck

[OutlawEX]

U willl love this mod i had it done to mine,but its not gonna be ball pulling torque compared to urs now...But u will see a difference and a Pistion is right around $110 and a cam is like $150..

[Ex'r Marlin]

Sorry I can not help you about the expected "horse power" gains you will get, but it will be noticeable!:)

As for using race gas at a 11:1 compression, it is recommended to use 50% race gas and 50% premium pump gas. (I have a 10.8:1 compression that I do this for. From reading what alot of riders recommend, I think if you want to stay with premium pump gas, go with the 10.5: 1 compression. Again, this is only a recommendation from what I have read on here, and there has been excellent replys and threads on this subject that has helped me greatly!:cool:

Good luck!:)

Lincoln Nebraska, huh? Do you know Josh Hallett? He is on this forum from time to time, and he too is from Lincoln.

[GoLikeHell]

I run pure 93 Octane and I havent had any probs. One thing you will notice is the bike will pull hard all the way to the rev limiter. Best bang for your buck. Go to www.moto-man.com, they have good prices and great service ( Local shop for me). I added a WB rev limiter to raise the limit, but the bike will not start if the battery is not 100% ( soont to have a fix for it)


Mark

[Scott400EX]

I have done the exact same thing to mine. hotcams 2, 11.1 wiseco, and TI valve springs. and WOW a ton or extra HP!!!!
I beat my friends piped and jetted 400ex by 15 bike lengths where before we were dead even!!!!!!! Craptors look out!!!

You wont be disapointed at all!!

[TEEGUNN]

Hey, thanks everyone! I think I might do this after Xmas! I have run 50% race gas before and noticed a small difference in power from just that. But sometimes race gas isn't available and I would like to have the option to run pump gas. Maybe I'll stick to the 10.5:1 comp piston. I don't know Josh Hallet. How old is he? What's his handle on this site? I actually don't ride much around Lincoln as there aren't many good spots close by. Thanks for the help!

If you noticed a diff with race gas on your stock compression piston what was the diff?

Reason I ask is it does burn much much slower than the premium unleaded and if your motor wasnt making the comp it should have been slower.

It will depend on what the "actuall" compression of your engine is not what the piston is rated at for octane requirements. This will vary motor to motor and you need to actually assemble you r motor to find what you have, so yo umay very well be able to install the 11:1 and still use pump gas.

[krazykurtk]

To really get the HP gains your going to want a carb with the piston & cam. Think about it. It's like the heart. What pumps blood to the rest of the body?

[TEEGUNN]

Well, the difference with race gas was small. I actually usually run premium pump because it is easier to get and race gas goes bad fairly quickly. The quad just felt a little "snappier". Also, the guys at my local quad shop think I should do the port and polish at the same time. They think it is a waste to crack open the engine and not do that while they are in there. I've heard good things about aftermarket carbs too, but to me they are pricey. About twice as much as a good slip on silencer. I mean, it would be pretty easy to sink $1500 into this bike that is already becoming dated. Suzuki now has really good offers going on financing too. But I really want to stay red! The 400ex will do me fine for the next couple of years when HOPEFULLY Honda will put their crf 450 engine in an updated 400ex frame. Now that would be NICE!:D