Adding Decomp to Hotcam

[fauxamish]

Is it possible to add the stock decomp mechanism to a hot cam? The reason I am asking is my bike is kickstart and its a pain to start without any type of decompression.

If its not possible, does anyone know how the manual decompression works on an XR400? Thanks

[mlabarca240]

Imo the easiest thing to do would be to swap with a diff cam. There are other cams that are comprable to the HC you are running and they utilize a decomp mechanism. I mean, since youre gonna be in there already. I'd like to hear from some others about this.

[fauxamish]

I've got a stage 2 right now. I was planning on going to a stage 3 when I put a stroker crank in. What would be the best cam to run with a stroker?

[mlabarca240]

I've never built a stroker so I couldnt tell you all about it but most of the guys I talk to run the stage 3. You'll be fine with the stage 2 but the stage 3 is specifically built for big bore/stroker motors with alot of airflow. You may have to start thinking about different rockers and springs with the stage 3.

[NacsMXer]

Originally posted by mlabarca240
I've never built a stroker so I couldnt tell you all about it but most of the guys I talk to run the stage 3. You'll be fine with the stage 2 but the stage 3 is specifically built for big bore/stroker motors with alot of airflow. You may have to start thinking about different rockers and springs with the stage 3.

Not really, the stage 3 is still a "drop in" cam just like the stage 1 and 2. Designed to work with stock parts. It is more aggressive than the stage 2, but not enough to necessitate upgrading valvetrain components. It's actually quite mild compared to some of the wild cams available for the 400EX. The manufacturer will usually specify if valvetrain upgrades are necessary.

And no, it's not possible to add the stock decompression mechanism to a Hotcam, sorry :ermm: I'm not sure how the XR400 decomp operates, but you could post in the XR250/XR400 on Thumpertalk. There's a lot of people over there that could explain it.

[fauxamish]

ok, I'll either look at getting a new cam when I rebuild the motor or getting a valve cover for an XR400. Thanks for the help

[mlabarca240]

Nacs, thanks for the added info. I'm always looking for bits and pieces of info to fill the voids :devil:

[NacsMXer]

Originally posted by mlabarca240
Nacs, thanks for the added info. I'm always looking for bits and pieces of info to fill the voids :devil:

Not a prob ;)

Just wanted to get the right info out there in case people run across this in the future. Wasn't meant to call you out or anything and i'm glad you didn't take it that way :)

[sneaky11]

Originally posted by fauxamish
Is it possible to add the stock decomp mechanism to a hot cam? The reason I am asking is my bike is kickstart and its a pain to start without any type of decompression.

If its not possible, does anyone know how the manual decompression works on an XR400? Thanks

Got a question for you. What's involved as parts to get the EX kickstarted? Do you just have to change clutch cover and kicker assembly from a XR and throw that in?? thx dude!!

[fauxamish]

To do the kickstart on an EX, you need an XR400 tranny, kicker gear and spindle, idler gear, clutch basket and clutch cover. There is nothing really gained by going to kickstart unless you remove electric start.