Ive got a 01 400ex. It has a scorpion slip on exhaust. I just put in the wiseco 11:1 comp 87mm piston. So far it rides great, no smoke. very powerful. But I think im gonna put in a Cam stage2. It should make a big difference? Also i want to go down one tooth in the front and put in a stage 2 rev box. this way i will get more torque but wont lose any top end.

What do you guys think?

Also will i have to jet when i put in the cam

 

cams dont make too much difference 2-3 hp depending or your engine head porting etc. when i built my 416 i left the stock cam because they give you really good bottom end. I owuld also look into a hd valve spring kit if your putting a rev box jus for good insurance if your gona have 2000 more rpms on top end.

 

well the stage 2 rev box off ebay claims to gain 750-1000rpms over stock. and i have this calculator program that u can enter your rpms and sprocket size and tire size and i should actually gain about 1mph on top end with the 14tooth sprocket and rev box combo.

so hopefully the stock ones will be ok they claim that u can use all stock springs and rockers

 

it matters how u ride if you should replace the springs i had this problem on my 200x if you ride high rpms a lot you should think about replacing them. also i have discovered the frames on 400exs are pretty weak if you do much jumping youll want a gusset kit

 

yea the bottom side of my frame in the front has cracked all to hell and im gonna cut all the bad **** off and weld on some 1/8inch plate to beefen it up and also weld on some 16gauge sheet metal to create full skid plades on the undercarriage.

What gussets are u talkiung about. I dont jump mine. almost never i think its stupid because it just tears them up and i would rather baby mine than tare it up

 

first off jumping dont tare them up if u know how to land thers plenty of people who make gusset kits bare is one i can think they are just supports you weld in on the frame. I broke the whole front top shock mounts out twice and one of the top bars broke about half way between the gas tank but i had 10 ft of air and landed wrong lol but better the wheeler than me

 

ya so jumpin can also be more damaging to me than anything. Well last night i put some rhino liner on my frame because it had some surface corrosion so i removed it and put that **** on their to protect from rust i live an hour from the gulf of mexico so salt is a bid deal down hear.

Im thinkin about paintin my plastics. Using plastic adhesion promoter first and then painting them with some helicopter paint that i get from work.
Do you think that the paint will actually last or should i abandone this idea.

 

iv heard if u sand it and put 8 to 10 light coats on it holds up well but i have aslo seen people use bed liner i think that would be the best because it wont come off and probably strengthen it

 

I know this is older than dirt, but I hope you put a 450r timing chain in it too! Because once you start pulling more HP out of those engines, the timing chains usually are the first thing to straty to fail… They stretch and they will start skipping teeth because the tensioner can’t take enough tension out of it, to hold timing….