cam chain replacement

[Knarf0486]

I'm going to be replacing my cam chain on my 400ex this weekend and I was wondering if anyone had any tips or tricks to make the job easier. if you got anythin post it up. thanks

[Old Head]

Best thing i've found is by the manual for the bike and read over the chapter a few times, which eliminates how many times your greasey fingures will have to touch the pages.

[greg_gorrell]

i rebuilt my engine and when i finally got it running again the cam chain tensioner failed causing it to strech badly. so yeah it was a pain in the *** tearing it back apart but heres a few tips to make your job go a little bit easier:

get a clutch removal tool or whatever its called. you need something to hold the basket from spinning so you can pull off the sprocket on the bottom that the chain slides onto.

make sure your tensioner is in good working condition. believe me, youll wish you did.

you dont need to take your cylinder off or anything, just the head. i know it might be obvious to some people but i have seen people changing their timing chains and had the whole top end apart.

most of your problems are gonna occur in the bottom end where you take your clutch cover off. so dont mess with anything down there unless you know what your doing.

also while your down there, there is a screen that slides in horizonally. its like a large oil filter, clean it. i had a bunch of silicon in mine so i was happy i checked it.

idk if you have anyquestions just ask.

[Knarf0486]

any ideas how much the tool costs?

how long does it actually take to do the whole process?

[Rico]

Buy a manual before you even think of starting the process. If not good luck on jacking up the motor...:eek:

Also if your doing it I hope your installing a heavy duty chain and not throwing another stocker back in there...:scary:

[Knarf0486]

already got the manual, and i got a stock one for cheap so im jsut going with that.

[Rico]

Originally posted by Knarf0486
already got the manual, and i got a stock one for cheap so im jsut going with that.

You can get the CRF one for like $30. don't waste your time putting the POS stocker back in there. Also if your going to that much trouble drop in a cam or piston or upgrade your clutch.

[Knarf0486]

wish i had known that beforehand. i plan on selling it pretty soon anyway so there wouldnt really be much of a point in putting that kinda stuff into it.

should i replace the tensioner along with the chain?

[Rico]

Originally posted by Knarf0486


should i replace the tensioner along with the chain?

As long as it will retract when you turn the small flat head screw then it is fine...:cool:

[Knarf0486]

thanks man

[BLEEDRED]

I didn't use the clutch tool to get the nut off. The nut is "staked". Meaning that once the nut is torqued you use a punch to dent the side of the nut to keep it in place. Use a dremel to grind the dented portion free. I used an impact to remove the nut. You should replace the nut with a new one and stake it in place. I used a rag and good pair of gloves to hold the clutch basket while torquing the nut with an impact. Worked fine for me for over a year.

Make sure you have a new gasket for the case cover and spend the time to clean the gasket mating surfaces really well. I used a little laundry detergent to wet the gasket and then scraped it off with a small block of wood.

Just make sure you read over everything really well before you get started.

I think a new stocker chain would be acceptable but if you have a heavily modded motor it will benifit you in the long run to go with the heavy duty CRF chain. Then again if you are selling the machine, it won't be your problem...good luck!!

[honda460ex]

Honestly, when it comes to the crf timing chain, you all can have them. I own two 400ex's, you can see what all my race one has done below.. Some will probably mouth off about this and say I'm stupid, but stock timing chain. My other 400ex has a 426 with a 12.5 to 1 JE, web cam, port and polished head, rockers hard welded, it produces maybe half the power my motocross 400ex does and it had a crf timing chain in it. Key word, HAD... It stretched and jumped two teeth on the sprocket. Luckily it didn't jump anymore and I was just able to replace the chain. My experience with them has been bad. But the whole chain replacement is a walk in the park. It will probably take you a couple hours, but with experience, I've gotten it down to around 45 minutes on a good day...:p

[BLEEDRED]

It stretched and jumped two teeth on the sprocket.

This is the first I have ever heard of a problem. Are you sure your tensioner wasn't damaged? I have had the CRF timing chain for a year with no problems.

[honda460ex]

Yeah, honestly the tensioner was good and the guides. They are still in the quad with no problems with a stock chain now.