Cam Lobe Position At Tdc???????

[DIRTCONVERT]

I hope someone can help with this seemingly simple question. I have the original Yamaha XS manual and with the alignment holes straight up at the arrows on the cam caps, and the piston at TDC(#1 cyl.) and the pointer at "T", where are the cam lobes pointing on the #1 cylinder? Mine are about 20 degrees from straight up and pointing towards eachother? Every mechanic I have talked to says that this in not right, inline fours should have the cam lobes pointing directly towards or opposite eachother. Please someone help as I took my head off without keeping notes and I dont want to bend valves again!!( I think I bought all the remaining new valves out there!!lol)

[Ken Talbot]

You are on the right track, Dirt. With the dots aligned, the cam lobes for #1 should be pointing slightly towards each other:



Just to reiterate, here is the valve timing procedure again:

5. To start the valve timing sequence, install a dial indicator in cylinder No. 1

6. Rotate the engine in a clockwise direction until top dead centre is found for cylinders No. 1 and No. 4.

7. With cylinders 1 and 4 at the top dead centre, loosen the screw on the crankcase pointer and align the pointer with the “T” mark on the timing plate. Recheck the top dead centre and alignment of the pointer and “T” mark. When all are aligned, tighten the screw.

8. Slip the cam chain over the sprockets.

9. Lubricate all cam caps and cam bearings surfaces liberally with oil.

10. Place the cam caps in their proper positions. The caps are identified “I-1” through “l-5” for intake and “E-l” through “E-5” for exhaust. Place the centre dowel pinned caps in position first and then position the remaining caps. Install the nuts and washers only finger tight.

Caution - The cam caps must be tightened evenly or damage to the cylinder head, cam caps, and cam will result.

11. Torque the cam caps nuts in two stages and finally torque to the specification.

Tightening torque: 1.0 m-kg (7.2 ft-lb)

J. Cam chain, cam sprockets and chain
tensioner

1. Rotate each cam shaft until the dot on the cam is aligned with the arrow on the centre cam cap

Caution - Use extreme caution when rotating the cams. Two possible dangers exist. First, the wrench may contact the head and fracture it. Or second, a valve may become bent if the cam is turned the wrong way.

2. Carefully lift the cam chain from the intake cam sprocket and pull upward to remove any slack in the chain between the crankshaft and the intake cam sprocket. With all slack removed. place the chain back on the cam sprocket.

3. Grip each sprocket simultaneously and place them on the crankshaft shoulders
while continuing to keep tension on the chain from the crankshaft to the intake
sprocket.

Caution - Use only the special hardened shoulder bolts to install the cam chain sprockets to the cams. Make sure the rollers of the chain are centreed on both chain tensioning slippers.

4. Rotate the sprockets slightly to align the bolt holes and insert one special bolt in each sprocket.

NOTE:
Tighten only finger tight at this time.

5. Install the guide stopper.

6. Rotate the crankshaft approximately 45º and align the “C” mark on the timing plate with the timing pointer.

7. Compress the cam chain tensioner and lock in the retracted position.

8. Install the chain tensioner to the engine and torque the bolts to the specification. Tightening torque: 1.0 m-kg (7.2 ft-lb)

9. Release the tensioner holding bolt, an audible click will be heard when the
tensioner is released.

10. Torque the holding bolt and the lock nut to the specifications.

11. Rotate the crankshaft more than one full revolution and align the “T” mark on the timing plate with the timing pointer. With the crankshaft at the “T” mark, the dots on the cams should be aligned with the raised arrows on the centre cam caps. If they are not aligned, disassembled the sprockets and chain tensioner and repeat above procedures.

12. Rotate the crankshaft and install the two remaining shoulder bolts into the cam sprockets. Torque all four sprocket holding bolts to the specification.


Caution - Be sure to attain the specified torque value to avoid the possibility of these bolts coming loose and causing serious damage to the engine.

Tightening torque: 2.0 m-kg (14.5 ft-lb)

[DIRTCONVERT]

Thank you. I was beginning to think I was crazy!! I have gone through 3 sets of valves. First ones, my fault entirely I set the timing 180 deg. off(don't ask), then when I got new valves installed the timing chain slipped off the crank and bam, here we go again. Finally, I couldn't find new valves so I ordered some "good" used ones from CRC and they weren't the right valves for my bike so the clearances were HUGE! I am good thanks to L. LLoyds. So the bike is back together and I was buttoning up the top end and wanted to make sure I got everything right. Thank you..... I will post pics of my ride in the next couple of days, I have been working on her since last Feb. 2005.