big bore and cam help and advice!

[bad_shee05]

hey all. I have an 05 ex that i want to give a bit more grunt to. Its been jetted and has a full supertrapp exhaust and tires and wheels but id really like it to keep up with my banshee just a little bit better so i decided i want to go with a cam and a big bore kit. Well i dont even know where to start. Should i just bore it out to a 426 or a 440 and should i use a stage 2 cam? Any cheap places to get the parts and can i have my local machine shop install the sleeve for me or is there something special i have to do? and last, would it be worth my wild to give it a port job and bigger valves while im in there? Thanks alot for all your help. I tried to search the topic but cam is under the 4 letter word limit. Thanks!

[smorris1]

I would go with a 416 11:1 piston with a stage II hotcam. The 416 has plenty of power and it alows you to go bigger if you decide to over time. While the engine is apart I would get a crf450 cam chain cause its way more heavy duty. Port and polish is always good but not necessary. I would do it if you have the money, same with the valves. I would get the parts from magicracing.com or rockymountainatv.com cause you get free shipping after you spend over a certin amount. Your local machine shop should be able to re sleeve it but you wont need to with the 416. You will just need it bored.

[BigBore24]

ive got a 440 with stage 3 hotcam and 450r carb. and i am really happy with it. a lot of people are gonna tell you not to do a 440 but if thats what you want then i say go for it. i agree with the timing chain replacement and also youl need to do something with the head studs. port n polish and bigger valves would help out, but unless you really want to throw a lot of money at it i dont think itl be worth it. a machine shop can change the sleeve and bore and hone it for you. i would shop ebay as well for your parts

[jedneck]

I got a 440 cylninder and piston for sale. The piston is a new in box 89mm 11:1 wiseco. The cylinder will need to be bored to fit the piston (it's a 88.5mm bore). $200 shipped

[drew416ex]

Originally posted by smorris1
I would go with a 416 11:1 piston with a stage II hotcam. The 416 has plenty of power and it alows you to go bigger if you decide to over time. While the engine is apart I would get a crf450 cam chain cause its way more heavy duty. Port and polish is always good but not necessary. I would do it if you have the money, same with the valves. I would get the parts from magicracing.com or rockymountainatv.com cause you get free shipping after you spend over a certin amount. Your local machine shop should be able to re sleeve it but you wont need to with the 416. You will just need it bored.

I say do this for now. I had a 416 and loved it and it gives you room to bore again later. Unless you want to spend a little extra and get a 440 then great. I currently have a 440 stroker and couldnt be happier with it.

[bad_shee05]

thanks for all the advice. I have decided on a hot cams stage 2 cam deffinately but im still not sure on the bore. Will the 440 really give that much more power than a 416? I plan on having this quad for a long time to come so i want it to last and my fiance will be riding it most of the time so it has to be as reliable as possible. I just want something that she isnt mad because she cant keep up with my banshee. I have found alot of kits on ebay that come with a 440 sleeve, piston, gakset set, and stage 2 cam for $350 and I am planning on spending around 350-400. I have heard alot of bad things about the 440's and seen alot of blown up ones for sale so im kind of scared to go that route but i deffinately need some more on mid to top end. Thanks alot for all your advice guys!

[bad_shee05]

I also forgot to add, i would like this thing to run on pump gas so whats the highest compression piston i can get and still be able to do that? 11:1 or 12:1? Thanks again!

[drew416ex]

The highest I would go on pump gas is 11:1. As far as power diff. between the two. Its all in how you build it. I had a 416 that would take many 440's. Same thing with reliablility, if its done right, you shouldnt have a problem. I just like the idea of a 416 because of being able to bore one more time before it has to be resleeved.