Help and questions about the timing and reinstalling the cams

[cook.675]

Im in the process of adjusting my valves; I put the new shims in and started to put the cams shafts back on

Now when I initially took the cams off, I turned the crank a little more past the "T" to have room to undo the remaining 2 sprocket bolts. When I was reassembling I was having trouble getting the orientation of everything correct and rationalized that I could just start over.

Since the cam chain was off, I turned the sprocket to line up with the "T", then i set both cam shafts in snug in place, with the lobes pointed outwards. Here is a picture of that looking towards cylinder 1:






I put the sprockets on and the chain; and noticed now when I did that the "I-" and "E-" on the sprockets were not exactly lined up with the cylinder casing. They were very close however, when you looked dead on the "I" was a little down inside the casing and the "E" was just above by a little bit. You can see in this picture. Sorry its not parallel but you can see the marks are slightly offset:





I got confused at this point because there was no way to make the dashes line up exactly without rotating the cam shafts which would unseat them or make then unstable. And so I figured that If I put the caps back on and tightened the bolts and tightened the chain that it would probably become flush.

I did all this and it didn't become flush but was still offset. Here is a picture with everything buttoned down. The intake sprocket mark is below but not by much.:





I thought that just a small nudge on the crank sprocket would line them up but it turns out I had to turn it a bit past the "T" mark. These two pictures show the new position of the T that aligns the sprockets:







And finally here is a picture of the Cylinder 1 cam lobes when my crank sprocket "T" is lined up with the crankcase line (and when my cam sprocket lines are slightly off)






So, is this correct? I assume it can not be because the cam sprocket marks are not perfectly aligned. If this is true, is the correct alignment of the cam shafts when I turn the crank past the "T as I have it set to align the sprocket marks, or were the cam shafts seated incorrectly from the get-go and thats why the sprocket marks do not line up?

Sorry this confuses me and gave me a lot of frustration because I tried to align the sprocket marks when I seated the cam shafts and before I put the caps on but I could not. If I turned one, it would be unstable, or one of the ends would come up high out of the groove.

If my cams were seated correctly initially (see picture 1), then the solution is easy right, I would just reseat them exactly as I did and set the crank sprocket "T" an equal distance below where it is now above, so that when I turn it a little the "T" and the sprocket marks will line up.



If the orientation of the cams is not correct could someone help me on where I went wrong and how to set it straight? It was definitly straight when I took it apart!


On an unrelated note, it was both my cylinder 1 exhaust valves that needed adjusting and I rechecked them after putting the shims in and reassembling and they were 10mm too loose

Thanks in advance for all your help!

 

[cook.675]

Wait just thought of this: Can I align the marks on the sprockets, slack out and remove the cam chain, turn the crank to the "T" and put the chain back on?

Am I missing something?

 

[trepetti]

I just finished my 2nd valve check, and dreaded the task of reinstalling the timing chain. The first time I did this a few years ago, I had an awful time.

This second time went smooth, thanks to some good advice from Finalimpact. Search for my thread: "HELP!!! - with my timing chain" and look towards the end for Finamimpact's instructions. It took me 2 tries, but it ended perfectly.

 

[cook.675]

Thanks for showing me that thread. Lord I wish I had just left the cam sprockets on when removing the cams!

The question I have is if my current alignment is correct or not? You can see in picture 6 that there is a point where the sprockets are lined up exactly; but for me this doesnt align exactly with the “T” on the crank sprocket

BUT; the crank sprocket has no way to “know” where it is; this T marking is to help us find TDC right?

From a mechanical perspective, if the cam sprockets align but the “T” does not; it doesnt really matter to the bike? Sure it would confuse anyone working on it later

The reason I ask is because if this true then I can keep the cams locked in place, slack the chain and move the crank sprocket back to make the “T” line up and put the chain back on

????

 

[bigborer]

From a mechanical perspective, if the cam sprockets align but the “T” does not; it doesnt really matter to the bike? Sure it would confuse anyone working on it later

Yes, it does matter, the crank isn't a plain spindle such as a gearbox axle, it's position will affect the position of the pistons inside the cylinder making them reach TDC at the wrong time. Hence the name "timing" - if the pistons are up at the wrong time they will hit the valves.

It would be almost impossible to try to keep the cams locked in place on this bike. Also unnecessary.

The easiest way to do it is:
-have the cams off
-align the crank
-install the chain
-using light force pull on the chain on the exhaust side
-install the exhaust cam in the correct position and tighten the cam caps.
-pull the chain to make sure there will be no extra loose chain links between the exhaust and intake cams
-install the intake cam in the correct position and tighten the cam caps, while being careful that the chain won't skip a cog on either the crank or exhaust cam. It should be a 1 man job but if you have an extra person willing to help have them keep in place the chain on the intake and exhaust sprockets. Another trick to release some chain tension and make the installation easier is to rotate the crank a few degrees after installing the exhaust cam.
-pull the intake chain guide towards the exhaust. It's not necessary but for extra safety secure it using a zip tie bundling the intake chain guide and the exhaust side of the chain
-install and "arm" the cct, and cut the zip tie (if installed)
-rotate the crank 720. If all markings are NOT where they should, there was a mistake so restart the procedure. It will not line up 100% perfectly but if it's as far off as in picture 4 it's safe to say that it's one tooth off.

 

[trepetti]

MOST IMPORTANT THING - After each attempt to line the timing up, put a socket on the timing wheel bolt and slowly rotate the crankshaft CW through at least 2 full revolutions and make sure there is nothing that stops it! This is an interference engine, so if the cam timing is off too much (and it doesn't take much) AND you hit the starter, you will severely damage the top-end....bent valves!!!

So to your questions - Pic 6 looks good for the cams, but in that position, with tension on the intake side of the chain, the 'T' needs to line up with the case seam. You are incorrect about the cam line-up vs crank line-up. If the cams are good but the crank is not, then you run the risk of piston to valve interference. There is a small margin for error (I think mine was 1/2 tooth off at the crank) but engine performance will suffer.

Don't worry about the cam bolts. Put them in snug then use the procedure given to me. The key was using the slack to your advantage by starting with the crank slightly past the mark then taking out the slack while turning the crank CCW. Once at that point. moving the crank WITHOUT moving the intake moves the slack to the exhaust side, giving you room to roll the exhaust cam in.

I just used this method and it worked.

Good luck...

 

[cook.675]

I see thanks alot for clearing this up. I didnt know the crank position was that important. With my limited knowledge and how the gear is symetrical it looked like it wouldnt matter but I see thats not the case.

Im going to have to take the cams off again to put these other shims in and Ill give it another go but I cant get them until tommorow

 

[TownsendsFJR1300]

I don't even see the mark on the case for the "T" to line up to..

Can you remove some old gasket material to see it?

IMO, just bolt the sprockets back on the cams and set in place as noted in post #5.
Crankshaft "T" , a mark next to it, lined up first, the exhaust cam mark(no slack), then chain to intake(no slack), keeping all marks lining up..

The tensioner takes up the slack.

.

 

[cook.675]

I was able to get new shims today so ai tried it again using your method.

It makes much more sense now. I did the exhaust cam first and everything was lined up PERFECTLY. Then I did the intake and its ALMOST perfect, its off ever so slightly.... I had to rotate a hair past T to get the sprocket marks aligned.

I will remeasure my clearances now; if they are all good would you guys reccomend just leaving as is or taking off the intake cam and trying for 100% perfect?

 

[TownsendsFJR1300]

Leave it... It appears the intake mark is right there...

If it was off a tooth, you'd see the mark not even close..
Looks good from here..

Remember, it's a chain. chains STRETCH with use/mileage. That alone, with the crank dead nuts on, the exhaust mark will be slightly higher(chain IS longer), the intake cam mark, even farther below the head surface. Again, with use, the chain stretch's and the marks don't line up exactly..

Put the tensioner back in and slowly rotate the engine until your marks line up again(just like NOW). They should be.

As noted, ANY INTERFERENCE, STOP, something's not right..

 

[cook.675]

Yah I did; these pics are after 4 revolutions.

I just checked the 2 valves I adjusted (both exhaust cylinder 1).. Still too loose..... m——-f——-!!!!!!

What is the minimum reassembly required to recheck the valves? I assume I can just line up and bolt in the exhaust cam only? Or does the whole system need to be put back in and cranked to set everything?

 

[trepetti]

Just my 2 cents. Loose exhaust valves are ok. The danger with them is that, as hot exhaust gases flow past the exhaust valve seats, the seats wear. This causes the exhaust valves to sit deeper in the seats and tightens up the valve clearance. Left unchecked, the exhaust valves will tighten to the point where they no longer seal, exposing the seats to full combustion temps and burning the seats.

So too loose on the exhaust is better than too tight. Exhaust lash will tighten up with wear.

 

[cook.675]

gotcha thanks everyone all this has been really informative. I couldn't even spell VALVE 2 days ago let alone adjust one!~

 

[TownsendsFJR1300]

I just checked the 2 valves I adjusted (both exhaust cylinder 1).. Still too loose..... m——-f——-!!!!!!

What is the minimum reassembly required to recheck the valves? I assume I can just line up and bolt in the exhaust cam only? Or does the whole system need to be put back in and cranked to set everything?

#4 exhaust valve was a knats hair too tight, (.001" beyond spec) on mine last year.

Leave the engine with all marks lined up (as you currently are).

1-You can stuff a rag around the lower end of the crank to keep the chain from jumping off the lower sprocket.

2-zip tie the chain to the intake cam( that position won't be changing).

3-Pull the tensioner out.

4-Now you can rotate the intake cam (for chain slack) some so you can pull the exhaust cam(with sprocket attached).

5-Pull exhaust cam and adjust shims as needed..

As you already adjusted with a shim and it's way out, your likely not doing something correct there.. Measure the gap(I did by thousands) and see what the gap is. Compare to spec's and see how tight it should be... Now you know how much THICKER a shim is needed to get into spec's. Pull the current shim, measure, and take note how much a thicker shim is needed.

You can re-check the gap with just bolting the cam back in, very close to where it should be and know the spec. Once it looks good, re-install the chain/tensioner, rotate and re-check that valve..

When I adjusted mine (rag by crank /block, intake cam and chain "tied" together)
Just less parts to move around on ya:

 

[cook.675]

Thanks for the tips; heres what happened with the shims:

My two exhaust cylinder 1 valves were both .22. The shims that were in there, the middle number was illegible; I had a guess to what they were but was not certain. I measured with a micrometer i have and I got a number 10mm off from my guess on both;

I took both to the deslership; the guy measured them with his digital calipers (they were ~185 and 189). My micrometer i figured since it was measuring in the middle gave me a lower reading (the middle number was gone). I then asked him to calculate based on a .26 or .27 desired clearance; I didnt calculate myself before coming in since I didnt know the old values. He gives a 145 and 150 shim and I leave.

I shouldve calculated my self but did not unfortunatley. I put these in; and I now get like .4 and .46 clearances. I dont understand at this point why it was off so much.

I re-calculate based on these numbers and decide I now need 2 165’s. I find a shop in town open on Sunday and I grab them. I put them in and remeasure.....

.40 and .40. ARRGGGG!!!!!

After some thinking I think I figured out what happened. With the 145 and 150 shims the clearances must have been off the scale (max) where the measurement no longer is accuarate; the shims were probably so small it was like not having one at all and the 165 I calculated was meaningless (as we can see it gave me a clearance of .40)

I calculated again based on the 165 shims and the .40 clearance and got 180. Then I went back and did the original calculation based on the measured shim thickness from the dealer and my original .22 clearance and got..... 180.

And now I realize the dealer did the calculation wrong. My own fault for not double checking. Wouldve saved me ALOT of time. Oh well. I got the 180’s this morning and now the clearances are perfect

 

[cook.675]

As good as it gets!

 

[TownsendsFJR1300]

Pretty close....