Need some help again 04 450

Alright finaly got my brand new cylinder and 13.5-1 piston. In the process I have hit two snags.

1. The rotational angle torque thing didnt seem to work well, the bolts were greased and I tightened the bolts to 30NM in 3 steps, and then loosened them all the way. Then I tightened them to 20NM and then tried to get the bolts to 180 in two steps. The bolts all came out to have a torque greater then 45 foot pounds to get it to the full 180.

This cant be right? I think I saw somewhere the finaly torque for the head should be 27 foot pounds? Should I take it apart and start over lest I screw something?

2. Cap caps, I took the bolts for these out in two steps and took every precaution not to screw them up. Now when I try to put them in it seems I have failed miserably. I cannot come anywhere within 5 foot pounds of torque. I can sieze the cam up by pressing down on the cap. When tightening down the cap bolts, long before the cap meets the head the cams are bound up. THere doesnt appear to be any wear on the bearing surface or on the cam accept for very very minor scuffing. Now what seems to be the problem is that valve clearences are too tight (cant tell until I get a feeler guage) but why in all hell would the clearences change? Could it be that I am not seating the big ball bearing down enough? Should I tap it down witha rubber hammer? and then try again. Either way it seems there isnt enough clearance for the lobes no matter what.

Any help would be appretiated.. thanks guys

When you follow the manual with the 180 degree method, the torque on the head bolts is much higher than 27 ft-lbs, but I did it by the book, and haven't had a problem. Cam caps. I would mark your bearing/journal surfaces with black marker or someting like that, and try to find out where it is hanging up. You might try giving your ball bearing a very light tap to help seat it, but it shouldn't take much. Finally, I am assuming you aren't trying to put the cams in with the lobes down, right?

For the cams that was going to be my guess too. Make sure the lobes aren't anywhere near the valves. Just the pressure of the valve springs is enough to make the cam hard to turn by hand. Also be sure you're using some assembly lube in there.

First, on the head, never loosen the head bolts after torquing them without replacing the head gasket. Yes, you can get away with it, and yes, I've even done myself in a pinch, BUT, to do so is pushing your luck pretty hard.

On the cams, I don't know what torque value you're using, but 7.2 ft/lbs (86 in/lbs) is too high, IMO, and it is my understanding that Yamaha lowered it for the '05 manual. I use 75 in/lbs (6 ft/lb) on both bikes, and I have no problems with either.

In the manual, the procedure for checking cam clearance is shown. Get the Plasti-Guage at any auto parts store. It comes in two (or more) sizes, so get the one for the right clearance range. To correct a slightly low clearance situation, get a sheet or strip of emery cloth of about 300-400 grit, and tear a strip about a foot long. or as long as you can, and about 1/4-5/16" wide. Clamp the cam very carefully between two pieces of wood, and wind the emery cloth around the shaft so it goes completely around at least once, hold one end in each hand and polish the entire length of that section. Check your progress occasionally, and be certain you get it completely clean and free of grit before checking the fit in the engine.

It is not that unusual for there to be a bit of resistance in the cams on these, but how much is OK is a judgment call, and there's no way I can really tell you how to tell. Your best bet is to check the clearance and/or have someone look at it.

Edit: I missed the part about tight clearances. There are a couple of possibilities. One is like the following post points out, the shims aren't seated. Another is that you may have mixed the locations of the lifters/shims while it was apart, and gotten some or all of them in the wrong spot. In this case, since the lifters are often slightly different thicknesses, all bets are off, and you'll have to reshim the whole thing. Some will be tight, others loose. The third thing is that it had tight valves when you took it apart, but didn't check. That would be a valve wear issue. Wait until you check the clearances, and that will help you figure it out. But if any are tight, that explains the cams binding.

Now what seems to be the problem is that valve clearences are too tight (cant tell until I get a feeler guage) but why in all hell would the clearences change?

I'm going to guess that the shims under the caps are not seated correctly on top of the valve stem. Take the lifter like caps off and make sure the shims are in correctly. While your in there make note of the shim sizes in case you do have too re-shim in the future.

Thank you guys, I just followed the manual for the head tightening and it told me to loosen the bolts after I torqued them and then retorque. I was trying to install the valves where they would be at TDC as the manual states but still was having serious binding issues. I couldnt have mixed up the lifters because I didnt yet take them out. Then when I realized they could be a problem.. I took them out one at a time and seated the shim with still no success. When I took the bike apart I noticed that the cams moved relatively freely (I could move it with 2 fingers until the lobes hit) But now as soon as the cap comes anywhere near comming flush with the head its binds the cams. I was aiming for 5 foot pounds but I couldnt even get anywhere near that. Now with the cams torqued I can still move them.. but it takes two hands and some good force which I would say is incorrect. I will see what else I can find out today. Once again thanks

Following the manual procedure and loosening them as prescribed is different than doing the entire thing and then loosening and trying again. The difference is that with the factory procedure you will be retorquing the the loosened head to a higher value than it previously was tightened to, so the head gasket will be crushed farther. That would not be true if you went through the whole thing and then decided to do it over, which is what I was talking about.

The 20 NM called for is only 15 ft/pounds, far short of even the 27 ft/lbs the head used to be torqued to. Even the 30 NM in the next step is only 22 ft/lb., so the gasket is being crushed much farther in the second and third steps.

I only did the procedure once. torque to 30, loosen, then torque to 20 then do the 180 degrees.

Diode, you are right. If it takes a healthy two-hand grip to turn the cam, don't run it. I learned that one the hard way, ending up with smeared journals/bearing surfaces

Alright I tried again yesterday and for some reason everything worked correctly. I have absolutely no understanding of why that happened. Thanks for the help guys

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