Top end tear down question

My manual states after setting the timing plate to TDC, I need to remove the center cam shaft caps then remove the 4 cam sprocket bolts. The problem is, when it is set to TDC, 2 of the cam sprocket bolts (1 on each cam sprocket) is down under in the head a bit.

I can barely get to them with an open end wrench, but I don't know if there is enough space to get the bolts all the way out. Will I need a magnet to hold it when I get it close? Can I move the time plate just a bit so that all 4 bolts are more accessible?

I'm new at working around cams. Any tear down pointers on the 550's? I've got the manual & following it closely, I just need a bit more explanation. Thanks

 

When I took the cams out doing the head on my 650 I ran into the same problem. The Haines manual suggests loosening the two bolts in question BEFORE setting to TDC. As long as you rotate the engine by hand (or wrench) then you won't run the risk of damaging the cams or sprockets.

 

thanks john. how did u get the second bolt out when set to TDC?

I think its a high probability it could end up in the crank case.

 

i like that tip of loosening first

 

CJ Maxim,

When I did my top-end I rotated the engine CW (slowly), removed the sprocket bolts on the underside, rotated the engine CCW to TDC and removed the top bolts. After you remove the "hidden" bolts, the chain and top bolts will hold the sprockets in place until you remove the top bolts at which time you'll remove each sprocket from it's recess. Hope this helps.

 

when your taking it apart it doesn't matter, just so it's right when you put it back together

 

I think it's OK to rotate the motor to expose the just-covered shoulder bolt -- do these first -- then rotate back to tdc or bdc... Note, you should not remove (all of) the cam journals until after the sprocket shoulder bolts are off (out) -- removing the journals puts all of the valve spring pressure onto the cam sprocket shoulders and does not allow you to rotate the motor via a wrench to expose the just-covered cam sprocket nuts... It is unsafe to rotate the motor w/the journals out and the sprockets on

The sequence should be:

1. TDC (or BDC doesn't matter)
2. Remove sprocket shoulder bolts -- rotate cw (if TDC ccw if not) to expose hidden one, rotate ccw (if tdc) back to tdc remove upper shoulder bolt
3. slip sprockets off cams (loosens chain)
4. Remove chain guide
5. loosen and evenly back out journal bolts to prevent uneven rise of the cams (side to side)
6. lift sprocket(s) slide cams out
7. hold onto sprocket(s) lift out

hope this helps

 

Thanks for the responses everyone.

I might have messed something up (don't know if it matters cause I'm gonna take it all apart).

First off, the only thing i have off the engine is the valve cover and the cam tensioner. I was feeling around the cam chain guide & it popped up which put some slack in the cam chain. I turned the timing plate ccw (less than 1/4 turn) to pick up the slack & it didn't turn the intake cam. So I went cw (again, less than 1/4 turn) & it brought the tension back.

My worry is, now the cam sprocket bolts are in a different location on the intake cam only at TDC than they were when I first removed the valve cover. This will all be remedied during reassembly?

 

Yes you should be fine ... Get a manual please it states same seq as I posted .. I have a 650 manual if you want it PM me with email and I will send it...

When you popped out guide you took up slack that was "before" the intake sprocket and you moved that slack to "between" the sprockets ... When you moved CW you moved same slack to other side of intake sprockets where there should never be slack under operating rotation... But you're fine ... What matters will be assembly sequence which the manual will explain