Changing XR 400 Cam

[XRTony]

I have to remove auto decompress. I was thinking of installing new cam while I'm in there. Does anyone have a suggestion of what cam? I trail ride only and I'm keeping original piston. (Can I change cam without removing engine from bike?) Any infoe will help.

Thanks

[Trailryder42]

Why are you having to remove the auto decomp?

You're probably looking at something like a hotcams stage 1.

Yes, you can replace the cam without removing the engine.

If you don't have a shop manual, download it. You'll need it.

http://www.sendspace.com/file/ivcn6l

[moto_psycho]

go stage 3 mate, if u dont like it ill swap my stage 2

all the hotcams for the XR are incredibly mild anyway, i got the stage 2 and was told "FOR DESERT AND MOTOCROSS ONLY", put it on, besides a little more top end there was nothing too exciting going on.

and its very easy to change the cam without removing the engine. VERY ?

[XRTony]

Thanks for the info... The reason I need to remove it is it keeps sticking. When it does, obviously tough to start with a compression stroke...LOL Getting worried it may happen when I'm deep in. Would hate to push out. Too old for that stuff anymore...

[moto_psycho]

if you do cam it, change the carb, and dont just get a 36mm pumper, its gotta be a bigger bore 1, changed mine to a bst40 yesterday, been fiddling with jetting, got it perfect, the standard 36 could never feed the stage 2 cam, i am simply amazed with how fun to ride my bike is now

[XRTony]

Makes sense. May have to wait on carb change. I have 36 pumper now. I should also change cam chain also, right? Should I just get stock chain, or is there a better aftermarket one you would suggest.

[alarmin]

I have a Stage 1 HotCam with a Mikuni Pumper and I have no complaints. You will need to use the manual decomp lever with the HotCam though (or at least I do). You don't have to replace the cam chain unless it is stretched or if you have enough hours / miles where you would want to do it for preventive maintenance. I have heard they use CRF450 cam chains but I am not sure if there are certain years or if they are all the same.

[XRTony]

OK,..I'm going in, shop manual in hand. Can anyone give me an idea of any special tools or anything I may need before I open her up? Appreciate the help

[YetiX]

If you're just replacing the cam, no special tools are needed.

[moto_psycho]

Special, tool, a zip-tie, make sure you support that cam chain, cause if you drop it......

[XRTony]

I see in the manual that you need to make a stopper plate to reinstall the cam chain tensioner. Do you even need to remove it? Other than that I'm all set. Thanks everybody !

[Trailryder42]

Don't need to make the special tool. You can retract the tensioner plunger with a regular screwdriver. The special tool is just made in such a way as to hold it retracted.

Removing the tensioner gives you the chain slack you need to pull the cam away from the head to get it out.

I see in the manual that you need to make a stopper plate to reinstall the cam chain tensioner. Do you even need to remove it? Other than that I'm all set. Thanks everybody !

[XRTony]

I just watched a short video on the cam chain tensioner from someone on TT. A big help... Thanks to everyone ....I appreciate it

[XRTony]

last question....Someone told me that replacing the cam without a higher compression piston would make no difference...? Will I feel any more snap with the stage one and stock piston? I have a Mikuni 36 pumper, snorkel removed, 49 tooth rear sprocket, Big Gun Rev Limiter. When I changed the cam on my Harley, there was a noticeable difference. I hope someone says it's worth doing.

[Wild Alaskan]

you will need a magnet on the end of a drill bit ?

[XRTony]

what's that for?

[moto_psycho]

you'll feel a difference, but go for a bigger carb PLEASE!!!!

[Wild Alaskan]

whoa, guess i should refresh before i post, the magnet on the end of a long drill bit is for retrieving the cam chain when it falls ?

[XRTony]

The cam and gaskets are in. I'm doing it next Saturday. Should I change cam, then ride it for 20 min or so, then change oil and filter? Or change oil and filter before starting and breaking in cam?

[Trailryder42]

If you were going to change it anyway, do it now.