Timing chain installation

I've got an '06 450 and having real issues installing the cams and timing chain. I am not quite sure the front chain guide is completely installed. I pushed the upper locater on the front timing chain guide after I got the head torqued down in the small notch between the cylinder head and the cylinder, and checked with a flashight. After I pushed it back in as far as I could the top of the guide still contacted the exhaust cam with the chain out of the way and the cam fully seated. Should I loosen the head bolts and see if I can push the guide into the upper slot any further, or is that the correct position for it to be in? With the cam fully seated, how far do you think the top of the front chain guide should be from the teeth on the exhaust cam? Also when you put the cams in, do you put one cam in first instead of the other? Do you put the caps on the cams and put the bolts in at all, or do you put the chain over the cams and then seat the cams? Any help would be great.

I've got an '06 450 and having real issues installing the cams and timing chain. I am not quite sure the front chain guide is completely installed. I pushed the upper locater on the front timing chain guide after I got the head torqued down in the small notch between the cylinder head and the cylinder, and checked with a flashight. After I pushed it back in as far as I could the top of the guide still contacted the exhaust cam with the chain out of the way and the cam fully seated. Should I loosen the head bolts and see if I can push the guide into the upper slot any further, or is that the correct position for it to be in? With the cam fully seated, how far do you think the top of the front chain guide should be from the teeth on the exhaust cam? Also when you put the cams in, do you put one cam in first instead of the other? Do you put the caps on the cams and put the bolts in at all, or do you put the chain over the cams and then seat the cams? Any help would be great.

I believe you don't have the guide seated correctly at the bottom down by the crank. You need to make sure the guides are installed correct before proceeding. What you want to do once that is done is set the motor up on top Dead center. Your going to be installing the exhaust cam first. Pull up on the exhaust side of the chain and slide the exhaust cam in place with the dot aligning with the cylinder head gasket surface. Then slide the intake cam in place with the dot aligning. The cam lobes will be facing opposite of one another. Now you wan't to install the cam caps. Just run the bolts down until the caps are seated fully. Now install the cam chain tensioner. Release the plunger so there is tension on the cam chain. Now you can turn the engine over by hand and make sure all your timing marks line up and the cam timing is proper. I hope you are using a service manual!!!! It is all pretty self explanatory. Good luck!

thanks for the info. But, it is fully seated at the bottom, since I pulled the magneto cover off and have visually verified it. My main question is how far away from the teeth on the exhaust cam gear should the front chain guide be when properly installed(ex. 1/4 inch etc.). Right now, the top of the guide is in contact with the the gear just sitting there with it pushed in the top notch as far as possible.

If I remember correctly last time I did mine the bottom of the chain damper (part #8) http://oem.thumpertalk.com/2004YZ450Fcamshaft.aspx is pretty close to the timing chain. Actually I remember it being a little closer than that. Not sure about the top though?

thanks for the info. But, it is fully seated at the bottom, since I pulled the magneto cover off and have visually verified it. My main question is how far away from the teeth on the exhaust cam gear should the front chain guide be when properly installed(ex. 1/4 inch etc.). Right now, the top of the guide is in contact with the the gear just sitting there with it pushed in the top notch as far as possible.

Hard to say without seeing it. I know it shouldn't touch the cam gear.

If you have the bottom of the guide located correctly, and the guide touches the exhaust cam, the upper locating pegs were pushed back out of their socket when the head was set in place. The only way to correct this is to raise the head off the cylinder about a half inch and reposition the guide. This is a very easy mistake to make, but I'd rather you didn't ask me how I know so much about it.

If you loosen the head bolts in sequence and in stages like you would if you were torquing them, you will not likely render the head gasket unusable, and you should be OK to tighten it back up.

This is a very easy mistake to make, but I'd rather you didn't ask me how I know so much about it.

Smells like "knowing-from-own-experiance" :thumbsup:

Shhhh! :thumbsup::busted: :busted:

if you've wrenched on the blue's enough. eventually you do this no matter how many times you've done it before.

yes, more experience talking.

thanks a ton guys, that was my suspician.

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