Removing camshafts (Maxim X)

Here I am with my next question. I’m not sure to move forward till someone ‘approves’ my plan of approach…

I measured my valves clearance twice (results see Shim Table.jpg). Now I have to remove the cams to check which shims (pads) I already have and which I’ll need. But this is where I get stuck.

85MaximXX has written a a "How to" (http://www.xjbikes.com/Forums/viewtopic/t=16298.html) but to be 100% sure I don’t screw things up I wanted to share this with you.

 

You missed step ONE> Jam a rag into the camchain slot so when you drop the screws you are removing in step four they don't fall into the oil pan and extend your project to step 246 ....DAMHIKT...but I was planning on pulling the oil pan anyway

You also need to remove the camchain tensioner if you didn't mention that. That will release the tension on the chain and make it possible to remove the cams.
Also, do NOT pull the spark plugs. It's way too easy for stuff to fall into those holes.

Note that when you remove the caps off the cams, the valves will push up on one end of the cam depending on the position. It will probably get a little "stuck" on the disc that holds the cams from sliding side to side. Usually a gentle prying on the end that is still down will get it loose. It's a good idea to try to pry the cam up on the "down" end while the cap is still compressing the springs a bit on the other end.
That probably doesn't make sense when you read it, but hopefully it does when you pull the cams.
I also like to mark the position of the cam to the gear to make it easier for assembly later.

I haven't read the write up you are referencing so I'm not sure everything he covered. He most likely explained it more elegantly than me.

 

Yes, he did mention the cam tensioner, but I didn't clarify that here! But thanks for you response and the tips. I'll think I'll have a try tonight! And I certainly don't want to move to step 246

I think I understand what you mean with prying the cams. I'll have a go and keep you posted! Thanks again.

 

Somebody suggested using a wire tie and securing the cam sprockets to the chain, since you need to take the sprockets loose from the cams anyway it ensures that you have no "one tooth off" timing issues when it goes back together (as long as you don't put a cam back 180* out.)

It sounded like a good idea to me.

 

That's even better I'm indeed most worried about the timing issues. And I think I can prevent it this way! Just in time by the way; the bike is in place and I'll be moving up and down between the service manual, this forum and the bike tonight

 

You probably already realize that you should have done this procedure a couple thousand miles ago... but, in case you didnt realize:
the clearance on most of your intake valves is 0, so the valves are being held open just a tiny bit, but there's no way to know how much. so when you pop the shims to get their current size, there will be no way to know which shim will actually be required to get the clearance back in spec...

so after you get all the shims replaced, and put the shafts back on, youre gonna wanna measure the clearances again to determine if the new/swapped shims did the trick, and hopefully none will still be 0mm...

here are some more thoughts:
if i were you, i wouldnt reuse(swap around) any of the shims that have a 0 clearance, as the lubrication probably has not been up-to-snuff, so the number on the shim is probably an overstatement, and the shim will wear really fast. also, take a good look at the corresponding lobes, and make sure there smooth and not cracked and generally in spec. give the shafts and journals a good once(or twice) over.
youre gonna wanna check the compression when all your clearances are > 0. you may have burnt valves.
use a torque wrench. the torque specs seem kind of not-tight-enough but those are all bolts which you do not want to strip. the sprocket bolt threads are surprisingly easy to strip--be very very careful.

with all that said, good luck to you on your endeavor! your bikes gonna run soooo much better!

p.s. come to think, i think the xs use buckets not shims to adjust the clearance. all still applies, tho.

 

Adding to pillowmaster comments:
You will want to swap shims on the valves you measure zero clearance and re-measure with the smaller shims you take from a different valve.

Say #1 ex is at 0 clearance with a 180 shim but you have a 170 on #3 intake. I would take the 170 and put on #1 exhaust and re-measure with the smaller shim to get a better measurement.

Also, since the X is "shim under bucket" the shims never wear. The buckets take all the abuse

Using a magnet to pull the buckets is another no-no since you potentially magnetize the bucket and metal parts may stick in bad spots
Keep each bucket with the hole it came from since there may be SLIGHT variations from one bucket to the next.

The shims like to "stick" to the underside of the bucket when you pull them. Then of course they fall off and roll into the drain to never be seen again.

 

It's such a FUN job to do...*note sarcasm*. I have to go in and do my 500 mile check this summer....Mike, bring me a case of beer when you come down would ya??

 

Yuengling Lager good enough?...or Lager Light so you don't get too fat :lol:

 

This is a bit after the fact, but when I took mine apart I first set #1 cyl. at top dead center, and added this paint after degreasing the metal parts. If the picture does not take my apologies. I did however get a micrometer and have found a couple of my shims are not exactly as advertised. Two of my 175's are actually 174, and another was one number higher. Picky, but can throw you off if swapping 2 shims that total .02 mm in error.

 

Guys, thanks for all the responses, you don't know how much of help you are to me !!

I know it should have been done earlier to this bike, but I bought it for a fair price in this state and I'm guessing the PO('s) didn't check them (at all?) ... The bike is currently at 32.000 miles.

On some points I handled correctly (I didn't use any magnetic tools and I did mark the sprockets and chain (see photo)) and so managed to read all the number of the shims (shims is the correct name??)...

Before I started I connected the sprockets to the chain and marked them. I also marked the sprocket and the camshaft, so I would certainly know that I wouldn't turn them 180 degrees.... . When I removed the tensioner I was able to get some freeplay and was able to lift the shaft (see photo). I took out all the shims and measured them. I didn't have to remove the shafts completely!

I considered the fact that almost every intake has 0 tolerance. I'm going to put in some shims that are 0.20 mm smaller and hope to get a clearance between 0,11 and 0,20 mm. If not, I'll go and have another try with smaller buckets (dams, keeps me busy....)

When I took a look at the buckets (I mean the silver things as in the photo) I noticed two of them are very weared?? Someone know how this could have happened? Because of the zero tolerance? Is this bad? Should I replace them?

Thanks again,

Frankie...

Ps. "Yuengling Lager"?? I have some "Hertog Jan", should try it!

 

Just another close up....

 

That would be the shim....about $10 here in the states

That scored bucket is NOT a good thing. You'll want a new one, but I would have about (40) of the in my shop. Whoever you get the shims from will be able to get you buckets.

Check the cam where those buckets were very closely. Either it has a nasty worn spot OR (more likely) you got a metal burr up there and it got smeared onto the camshaft.
Regardless it's not a good thing.

OH>> another little trick I learned. Put a piece of threaded rod all the way through the cam with nuts on each side and tighten it onto the cam. make sure you put a couple flat washers on both sides so you don't damage the cam. This will give you an easy way to spin the cam without trying to use the poorly shaped hex on the cams.
I think I used a 5/16" diameter rod (about 8mm)

 

The shims cost about 15 euros (20 dollar) if i buy them new
Luckily I can swap my old ones with the dealer and then they would cost about 7 dollar. Anyway's I'll need 20 so.............

Does anyone of you ever used the ShimPool as mentioned here: http://www.maxim-x.com/notes.html???
Or does anyone on this forum swap/deals them?

 

Hi I should tell you a bit more why I have my motor apart. It quit running due to low compression in 2 cylinders. None of my valves had zero lash as you have, however they were leaking air. My concern for you is that it is very possible that your valves may not be sealing properly....I know mine were not. It would be a sad thing for you to do all this work and then find out your valves are still not sealing. My suggestion is to take the head off, remove some of the valves and check their condition. I have a friend who rebuilds engines for a living give me a hand, he got me some valve lapping compound and I did each valve with a hand tool. He then had the head tested for sealing and it is now good. I also chose to hone the cylinders and put in new rings as well because a bit of grit caused some small scoring in 2 of them. I can send you pictures of before and after of my valves if you want. My email is: rommelm@telus.net Just make it clear in the subject of the email you send that you are from XJbikes....I do not open emails of unknown origin. I know this is extra work, but probably necessary to getting this bike running well. Once you know the valves are good then it is time to set the lash as all clearances will change if you end up lapping them.

 

Forgiven, why not just post the pictures here so that we can all see the difference?
I'm sure the rest of us would be interested too.

 

Well party because they would be kind of small, but here goes....before and after shots of intake and exhaust valves using a manual lapping proceedure. Note the light grey marking of the valve and seats after being lapped. My engine builder friend said this is just how they should look.

PS my pictures are sharp, somthing happend to some of them when loaded here, but the good ones show how the valves should look.....

 

Mike, thanks for all the info! I'm getting more and more adventurous with my bike this way... 4 weeks ago I hardly knew the basics of a engine and now I might be lapping my valves.

A friend of mine has the right tools to the the compression test, that's were I'll start (I think I should have started there in first place....) and I partly hope that I'll give me good results. If not, I'm going to unscrew the rest Thanks again!

 

Believe me I felt the same way. The only reason I am into my bike this far is because it no longer ran and I had nothing to loose by taking it apart. Now I am fairly confident that it will run well again. Friends got me to where I am on this project and I feel a lot more confident about working on my motor. The real test will be when I fire it up again......