Sandrider, Is their a reason your only using 10.5:1 piston? If you bump it to 11:1 it will help more for the bottom end and hp anyways, lets see also it shows K&N filter and you show MotoForce intake system are you going to use the motoforce filter or the K&N for the system is designed to use their filter, and one more thing for about $150 you can find a local shop that good and experienced in flowing the head and doing a killer valve job while they are in it. I did and that will be one of the most improvements you can do for hp gains and performance. If you don't have anyone and you want it done I will work with you to get it done here! set you up with the company. Reno, NV. right now as you look your going to bump the hp approx....ooh you did great on the complete pipe it will work best with the head flowed with the ceramic coated to flow better, anyhow...9hp gain give maybe another 1to2 +hp, if the head flowed and high performance valve job another 4+

 

4+ hp by getting a "high performance" valve job? Did I read that correctly? Not doubting, just questioning - I didn't realize you could get that kind of gain from it.

 

No not the just the valve job it's the flowing of the head that does the trick it allows fuel and air to come and go faster in the motor burns it quicker, the five angle valve job allows the air to flow faster less resistance is the trick polishing the exhaust helps the exhaust gas to exit fast all means more hp, it is the most effective way to gain in a motor mod.

 

Thanks huskerjim.

I think I can add that to the high compression piston and new pipe for next winter.....

 

Redex, what also I have done was Quench the Head, what that is I measured piston to valve clearance milled the head to bring the clearance as close as it can be and what it does is it allows the compression to be bumped more for like if you install an 11:1 compression ratio piston what really allows it to be a true 11:1 it the quench you have, by doing this you cna make sure it's a true ratio and even more, as well it allows the gas and air to expode even greater and it will let the bike rev quicker as well. BAM....you have a Sweet ride [img]i/expressions/face-icon-small-happy.gif[/img]

 

So I have gained 9hp that is pretty good the reason I went with the 10.5 is I wanted to keep the stock bore. I didn't want to do a 440,416 or 406. I really like the performance of the stock 400ex and didn't want to mess with a good thing too much. Honda makes a really reliable quad and I didn't want something I had to mess with all the time. I'am running the stock headpipe I just ran it up to LRD along with the Flywheel to get it coated. Mabey later on down the road I will throw a 416 kit in my quad but it should be pretty mean with the stuff I'am getting installed. Do you think it is a good setup. I'am thinking when its all put together I want to go get it dnoyed but you say it should add 9hp. Oh I will be running a K&N filter.

 

when you get it dyno let me know as well I kept my stock bore as well for the same reason but I went with the 11:1 wiseco and quenched the head. I don't like the idea of putting a big bore and having a problem with heat and I know alot og guys with the problem as well of warping too.

 

Ya know buddy I think me and you are the only ones who think the same. Everyone else says big bore more power but they don't understand you have other things that come along with bore kit. To do it right you should coat everthing, get a stronger rod, better valves and springs, figure out how to make it run cool and balance the crank. Anyways I heard Wiseco kits aren't the true compression ratio have you heard that also. Have you had any problems with your quad. Since you had the work done. Heating ect.

 

amen....................................[img]i/expressions/face-icon-small-smile.gif[/img]

 

Good comments guys - my brother and I were actually discussing this last night. Big bores might be great for a pure MX (or any race) bike - but if you do a mix of riding I'm afraid it would become more of a liability. Sure there are many differing opinions from those who have have done it - but it just seems to make sense to not take the bore any bigger unless you have to (i.e. - blowing the motor). Good luck with the mods Sandrider503... [img]i/expressions/face-icon-small-cool.gif[/img]