Need to put my head back on!!!!!

Ok so I got my head back from the machine shop and it looks great...only prob is I don't know how to make sure that my cams and valves are situated correctly. Please help me out, I am dying to ride. The valves are in the head and shimmed. I am at the point were I need to fit the head back to the block and bolt it all back together. Should I just be able to throw it on?

 

Following is an install guide. First I have to question how you know the valves are shimmed? Did you mark or keep in order the shim buckets and replace them back in their original position? This is the correct way. It is also good to write down all the shim thicknesses so that valve jobs are a snap in the future. Correct shimming can only be done by measuring the clearance between the cam lobe and shim. So the camshafts have to be in place. If the shop ground the valves then these clearances will change and having the thickness already will let you determine which shim to change to without removing it to see what size it is. I also left out the camchain tensioner setting before install since I don't know if yours is a manual or automatic tensioner. If you don't have a manual then ask for that info. The tensioner has to the changed or relaxed before it is inserted. This install is based on the 650 and 750 models. If yours is not one then inquire for differences before installing your head.


First thing is to make sure the crank is still at TDC. Then clean the mating surfaces on the head and cylinder block. You can spray a coat of copper gasket on the head & camchain tunnel gaskets for added insurance if you want. Place the gaskets wit teh tabs on teh tunnel gasket down. The rear camchain guide may need to be pulled forward if it catches on the head as you set it in place. Really good to have a friend when doing this especially for passing the camchain through the tunnel. Make sure all the metal locating dowels are in place if you removed any and that the oil galley orings are in also. If your bike has a YICS port then the orings for it need to be placed.
With this done the head can be put in place. Check that it is down, the camchain guides are in place and that the camchain is still on the crankshaft gear. If not turn the crank back and forth until it catches. The crank can be turned since the camshafts are out. Set it back to TDC and torque the head down according to sequence.
Now you can place the camshafts with their sprockets in their respective positions with the timing marks lined up. Pour oil onto the cam journals and then onto the camshaft journals before installing the camcaps. Remember that the camcaps are marked as to intake and exhaust and side. Then place the camshaft caps in their proper place and slowly tighten them down slowly alternating from one side to the other so as not to bend the shaft. Torque to 7.2 ftlbs.
Check the timing marks again on the camshafts and once dead on attach one of the sprockets with one bolt hand tight then rotate the other sprocket to align with the bolt hole by slipping it into the right chain space then onto the sprocket shoulder. I found it much easier to slip the sprocket forward or backward into a chain space and then to slip the sprocket onto the camshaft. Check timing and rotate the crank Counter clockwise with a 19mm wrench to the C mark. Here you install the camchain tensioner. Then rotate the crank Counter clockwise two full turns which is one full turn of the camshafts and check timing again at TDC. If it is off remove the sprocket on the cam that is off and move the sprocket in the chain to align the sprocket with the bolt hole and the timing marks. Once timing is checked again and is still spot on after 2 full rotations of the crank the other bolts can be installed and torqued to 14.5 ftlbs.

 

Thank you for the breakdown... helps a lot more than the manual did. My valves were shimmed and replaced into the head by the machine shop. My caps are on but only handtight. On the intake side one of the valves is not touching the cam. Is that normal? Or am I ready to begin the install?

 

Valves should have a gap to the cam except when on the lobe.

Technically - Valves don't touch the cam. On top of the valve is the shim bucket. The shim bucket holds a shim (what else) that rides on the cam.

The clearance between the camshaft and the shim (lash) needs to be measured at room temperature with the camshafts properly installed in the head.

You should check lash before buttoning it up.

 

Machine shop says that the shims and the lash are set... cross my fingers. He said to throw it on and turn the cams into place. So, I will begin. You guys have been an awsome help. I'll let you know how it goes. I will also have to post some pics of the mods I have made to my maxim xj 650.

 

One thing I will add to Carl's post is to make sure you have the intake cam in the intake journals. Quite easy to get them mixed up. As you tighten the camcaps down some valves will be compressed and some will not. It doesn't matter as long as the camshafts are in the right position and the crank is at TDC.

 

You know you have to take the cams back out before you put the head on, don't you?

 

Unless you get a Reference Manual ... preferably a Factory Workshop Manual for your bike ... you are setting yoaurself up for a DISASTER!

There are some procedures that need to be followed >> "To the letter" when reinstalling a Cylinder Head back on the Block.

You have to go through the Step-By-Step of TIMING the Engine and removing the slack from the Timing Chain.

The Very Best resource it a Factory Manual
The next best is Haynes.

You can't just plop the Head back on top and expect not to have a problem.

TIMING the Engine is the most Critical of Procedures.
If the timing isn't done right ... the Time and Money put into having your Head done by a Machine Shop will be wasted.

Before you begin ...
Get a Book and Study the Cylinder Head Replacement Chapter.
Be sure you understand everything presented in the text and how to do it.

THEN ... if you have any questions about HOW or WHY you need to do something ... come back and ask, in here, BEFORE you do anything that could set you back to Square One in the blink of an eye.

 

I am going to give it a try. I will take my time and ask questions when I have them... and I will have them.

 

The Cams are "Marked"

Be sure that you DOUBLE CHECK the work that the Machine Shop did and that you DO ... IN FACT ... Have the Intake and Exhaust Cams in the right Place.

Read the test and look for the Markings on the Cams indicating INTAKE, EXHAUST and the raised or drilled "Timing Marks"

Be sure to understand what you have to do with regard to Re-loading the Cam Chain Tensioner.
When the Head was removed the Tensioner extends to its full length and will need too be re-kocked (sic) to allow the Chain to be placed on the Sprockets and "Pulled-up" and across the Cams for an accurate timing of the Cams.

Don't do anything that you don't have a full understanding of the technique.

When you get it on there and you THINK its all Hunkie-Dorey ... Wrench-over the Engine by hand through a couple of complete revolutions real S-L-O-W-L-Y !!!

You don't wan't to find-out you missed-timed the Engine the hard way!

 

Talking with the machine shop, they said that I should be ready to put it on but need to line up the cams. So I believe they are on the same page. I do have the bible(manual0 and I will heed your advice to follow the directions precisely. Thanks Rick for the caution and advice. Thanks everyone else too. I would be lost without the help.

 

The Machine Shop isn't telling us how to best advise our Membership.

The Machine Shop is speaking in broad generalities. Of course you have to "Line-Up" the Cams.

It's HOW to Line-Up the Cams and Lay the loose Timing Chain across the Double Overhead Cams that determines the proper timing.
You cannot be off.
You need to be 100% Correct the first time or the Valves will crash into rising Piston Crowns and it don't take much to bend one.

The process is a step-by-step ... don't do the next-step until you are sure you did the last-step right procedure.

The element of precision cannot be over-emphasized.
I have seen too many Pro's get burned by not taking inventory of each step along the way ... and having the Engine BIND and needing to back-track in order to get the Timing right so that the Engine turns over without binding and the Cams not lining-up on their marks after a few rotations.

There's no close.
Only perfect.

Good luck.
Get it right!