n00b here... cam help

[blac00si]

A few weeks ago a bought a '04 400ex from my boss... here are the specs that i know..

K&N filter w/ prefilter
air box lid removed
WB E2 pipe
Jetted (not sure with what jets)

A friend of mine traded me some stuff for a webcam 450/451.. Me knowing nothing about 4-strokes, i wanted more power and figured that this would give me a little boost. I checked on webcamshafts.com and the said that stock springs were OK and hardwelded rockers were recomended but didn't say they were required.

So, my dumbass put in the cam without doing alot of research... I set the intake to .005" and exaust .006"

When i start and run it, its giving 'baby' back fires out of the carb, when i installed it i used some hotcam instructions i found online.

Since i didnt know alot about what i was doing i didn't let the motor run for more then 2-3 minutes with it doing this. I called a local shop and a guy told me that it is not a drop in cam and that i need to get hardwelded rockers before using it or the cam will eat my valvetrain.

So, tomorrow i will be reinstalling my stock cam.

Should i be worried about any damage to my valve train? Or should i be okay?

I have 7+ years of experence working on honda motors as i was a 'tuner'. hahahahaha So, i know my way around a motor. I just want to be sure that i'll be okay for my camping trip to the dunes this weekend.

Thanks guys! Im glad a found this forum. It looks like there is alot of great info here.

:huh

[lpmaster]

the cam is just of different desnity than the rockers, the rockers actually have a very hard face on them but its very thin and the cam will eat away at it givin the time, the backfire is not from damage to the valve train its probably improper use of your decompression mechanism(not sure if the web cam uses it or not) and you didnt say wheteher you removed it or not, or jetting, jetting will be seriously messed up when installing that cam voer a stock one.....do not worry about valve train damagefrom that little use

[dariusld]

What was the ticket for?

[400exrider707]

Im assuming since you used hotcam instructions, you pulled the spring and plunger for the decompression out of the head? Make sure you put it back in with the stock cam otherwise it wont run, and if you didn't take it out, make sure its still in its spot.

[blac00si]

thanks guys for the replys...


yes i did remove the spring and plunger, and the webcam does not use the decompression mechanism.

i've been searching for the stock valve lash on here but im not really finding what im looking for. I did find .006" intake and .007" exaust... is that correct?

I got a ticket for speeding... haha... i guess that all beaches in oregon boarding the pacific ocean are considered state highways with a speed limit of 25mph... he est. my speed to be "50+" mph, but i dont understand how he can guess how fast i was going and write me a ticket for it. Ohh yea.. it was $421 also.. :(

[lpmaster]

if i remember correctly ( i only read this somewhere else i think from someone pretty knowledgable that valve lashes are only there to help make up for the thermal expansion of that valve so once your motor is warmed up it expands and your lash is now almost zero, this being why high perfomrance cams that make more heat require a looser valve lash to make uop for the extra expansion.......i may be way off

[400exrider707]

Originally posted by lpmaster
if i remember correctly ( i only read this somewhere else i think from someone pretty knowledgable that valve lashes are only there to help make up for the thermal expansion of that valve so once your motor is warmed up it expands and your lash is now almost zero, this being why high perfomrance cams that make more heat require a looser valve lash to make uop for the extra expansion.......i may be way off

yeah thats the basic idea..


a stock 400ex is exactly what you have it set at. .005 in .006 ex. There is a range that they give you but that is what I always set mine at.

[lpmaster]

ya, when i was running a tsage1 the ticking was anooying me, even though it was only noticable at idle so i set it back to the stock 004, and 005 gaps and it helps quite a bit

and to be honest

i run a 440 11:1 ross, light head work, slip on, and i prefer teh stage 1 over the stage 2 for the dunes

with the stage 2 i ahve a hard time hill shooting in 3rd

[blac00si]

:D I just got done reinstalling the stock cam. Set the clearences to .005" in and .006" ex... It seems to be running fine.

Thanks to everyone for your help answering my questions. :)

[JOEX]

For future reference, riding pics without helmets are not allowed on this site;)

Welcome fellow Oregonian, how are things at Sandlake? I haven't been there in awhile....

[blac00si]

Sandlake was good, i went there on the 4th and it wasn't crowded at all.

What part of oregon are you from? Im headed down the Florence this weekend, i'll be staying at Driftwood II in dunes city.

[JOEX]

Originally posted by blac00si
Sandlake was good, i went there on the 4th and it wasn't crowded at all.

What part of oregon are you from? Im headed down the Florence this weekend, i'll be staying at Driftwood II in dunes city.
I'm in Oregon City. SL is alright for a day trip during the week but I very rarely go there on the weekends, too many people. This time of year probably isn't bad though.

Florence is great, stayed at Driftwood II many times. Horsfall is great too, it's a toss up which is better IMO. I haven't been able to ride much lately:(

[flamed360]

uhhh