Author Topic: CB500/4 cam removal (Read 6962 times)

BlindSight · « **on:** December 30, 2010, 10:16:37 AM »

was going by the manual online trying to remove the cylinder head and got stuck. im down to the cam and I have turned the chain tension screw in and tightened the nut taking some pressure off the chain, the manual then says to remove the 2 bolts holding the cam sprocket to the cam but I can only get to 1 of them and cant get the cam to turn...have tried searching to figure out how to turn the cam and I don't know if mine is just stuck and needs a little love or what but don't want to try and foce anything and risk breaking something.

BlindSight · « **Reply #1 on:** December 30, 2010, 11:12:19 AM »

how do I turn the crankshaft with the least amount of effort? I am pretty sure the pistons are frozen in the cylinder and it wont crank over with the starter and I tried using the kickstart but nothing moves when I use it unless its in gear and then the rear wheel spins but nothing in the motor.

Fritz · « **Reply #2 on:** December 30, 2010, 11:18:56 AM »

If your engine is stuck, you must either free it before you can take off the cam, or you should consider splitting the cam chain.
Are you sure that your pistons are stuck? Maybe the problem is your transmission.
Did you try to turn the crank in neutral using the rotor bolt?

BlindSight · « **Reply #3 on:** December 30, 2010, 12:55:42 PM »

not sure but the bike had been sitting for 23years so wouldn't be surprised if there is something wrong with them both.

BlindSight · « **Reply #4 on:** December 31, 2010, 12:18:42 PM »

SO I pulled of the right and left side cover and tried turning the bolts and still nothing...the notches on the right side where the points are that key up the nut onto the shaft just broke off when I applied a little force. Is there any other way to try and turn the motor over? going to try the atf/acetone mix and pour some down the spark plug holes and let sit for awhile before I try anything else but let me know where I should be applying force...pictures would be a big help too.

dave500 · « **Reply #5 on:** December 31, 2010, 01:38:02 PM »

drop the pan and have a look inside,it might be rusted solid,break the cam chain and remove the head.

BlindSight · « **Reply #6 on:** December 31, 2010, 02:59:31 PM »

Dropped the pan and it was nice and full with oil, everything is nice and clean and lubed up as far as I can see underneath. little bit of sludge in the bottom of the pan but no debris or rust. whats the best way to break the chain? I have a bicycle chain break tool but there isn't a spot where I can get the tool to the chain without the sprocket in the way. made some acetone/atf mix and sprayed down the spark plug holes. what should I try to crank on tomorrow after the mix has sat for awhile?

dave500 · « **Reply #7 on:** December 31, 2010, 09:02:01 PM »

the other side has the alternator,that has a nice strong bolt,it will be tight enough and strong enough to let you rock the crank back and forth,the other side is a little misleading with that large nut,youll need another advance unit now after breaking that one,use a six sided socket of the correct size and bar,just try and rock it back and forth untill you get it to turn over enough to remove the cam and head,that mix you made,pour a lot down the plug holes,does the bike roll in neutral?

BlindSight · « **Reply #8 on:** January 01, 2011, 10:46:46 AM »

Any way I could try and repair the timing unit? maybe drill and tap a hole to put a bolt or allen socket there to keep the not from moving.....part on ebay is at least $30. Bike does roll in neutral, rolled it up onto the trailer.

Bodi · « **Reply #9 on:** January 01, 2011, 10:59:11 AM »

That big nut on the advancer has suckered many of us into thinking it's strong. Someone must have an advancer they can sell you cheaper than new, or check out bike wreckers.
Remove the alternator cover and the flywheel/stator will be sticking out. A strap wrench, real or improvised, will put a lot of force on this and it is rather strong. Turning the nut on the end might damage it too.
Pouring an ounce or so each of penetrating oil down the spark plug holes will help free up rings that have rusted to the cylinders.
If still unsuccessful then just cut the chain. You can pull a new one in using the old by tying it to an end of the old one. Although stock is an endless chain it is not unusual to replace it with a rivet master link chain, and the riveted chain is quite reliable... don't use a clip master link. In the "old days" this was a good profit maker for a shop: they could charge the book time for cam chain replacement (several hours to completely disassemble and reassemble the engine) and actually put in a master link chain in an hour or so on bikes where it could be done in frame.

BlindSight · « **Reply #10 on:** January 01, 2011, 11:23:25 AM »

thanks for the tip, I started cranking on the alternator bolt and the cam moved about an 1/8th turn but then it stopped again and I felt like I was putting way too much pressure on the bolt so I filled with a little more fluid and stopped, will improvise a strap wrench and see if I can get it that way later today.

BlindSight · « **Reply #11 on:** January 01, 2011, 01:44:07 PM »

Tried the strap wrench and nothing so I added some more fluid and going to wait till the morning.

paulages · « **Reply #12 on:** January 01, 2011, 02:45:55 PM »

I used to have a spare rotor I'd welded a large nut onto for breaking free stuck engines. Now, I soak ATF/acetone mix or something similar in the plug holes, and use the rear wheel to rock the engine back and forth. try to work it into 5th gear, by rolling the bike forward and back while shifting, in order to make sure the gears move enough for the dogs to line up. Once you're in 5th, simply rock the bike forward and back and see if you can get the engine to move a little.

You can simply cut the cam chain as you're obviously going to have to pull the cylinders anyway..

BlindSight · « **Reply #13 on:** January 01, 2011, 07:39:47 PM »

Thanks, if I cant get it moving after another night of soaking ill try to rock it into 5th and see if that does the trick. I am going to try everything I can to not tear up anything else and while I wouldn't die if I had to cut the chain but already had to replace way too much on the bike from me taking the easy way out so the budgets getting tight.

camelman · « **Reply #14 on:** January 01, 2011, 08:19:54 PM »

You really don't need to worry about getting that camshaft out before you break your pistons free. Even with the camshaft off, you'll still have the issue of stuck pistons. The best way to loosen them is by rocking the bike in gear or applying torque to the crankshaft bolt. So, I'd recommend ignoring the camshaft issue until you have those pistons free. Then, once they are free, the camshaft will be a cinch to remove.

Camelman

daytonajoker · « **Reply #15 on:** January 02, 2011, 04:56:00 AM »

If your motor is seized and you have to break the chain to get the head off, you can reconnect it with a Honda OEM cam chain link Part# 14410-283-000 It needs to be "peened" as there's no clip holding the sideplate on....I used a punch and had my wife hold a heavy hammer against the other side while I gave it a couple sharp whacks....over 6,000 miles and no problem

BlindSight · « **Reply #16 on:** January 02, 2011, 07:39:32 AM »

Sweet daytona, thanks for the heads up...hopefully it will warm up a bit and I can try to get this thing to move again...everything has a nice layer of ice on it right now

daytonajoker · « **Reply #17 on:** January 02, 2011, 07:49:39 AM »

So it's really "Froze Up"

BlindSight · « **Reply #18 on:** January 02, 2011, 10:47:20 AM »

yeah the sun came out and warmed things up a bit but still nothing, couldn't get it into 5th but rocking it back in 4th wasn't doing a thing

BlindSight · « **Reply #19 on:** January 03, 2011, 01:50:59 PM »

yeah 2 more days of it soakin gin atf acetone mix and still cant get it to budge with the alternator bolt or the strap wrench around it...and can get it into 4th and rock it back and forth but it wont turn over the wheel will just slide forward(need a chubby friend to sit on the back and put some extra weight on the rear wheel but doubt it will help much) and can't get it into 5th. will probably just break the chain tomorrow. With the new link could I just use a c-clamp to squeeze it together?

scunny · « **Reply #20 on:** January 03, 2011, 02:04:56 PM »

small c clamp will do, just a bit at a time keeping it square. some joiners are "soft link" these have softer metal tips somtimes with an indented point and require peening over, others are a press fit and don't get peened.

BlindSight · « **Reply #21 on:** January 03, 2011, 11:50:05 PM »

cool thanks for the advice.

dave500 · « **Reply #22 on:** January 04, 2011, 01:57:19 AM »

once you break the chain and remove the head,rapping the pistons which sit higher than the lower pair,with a block off wood and good hammer might start it moving,dont pry between the fins to dislodge the barrel,theyll break like clay.

Mark M · « **Reply #23 on:** January 04, 2011, 08:05:30 AM »

Heat is your friend - get a blow torch on the cylinders - butane ones that plumbers use are perfect.

camelman · « **Reply #24 on:** January 04, 2011, 06:59:05 PM »

I wonder if those bores are salvageable anyway. If not, then a big effen hammer might be right up your alley along with a new set of pistons and a bore job.

Camelman

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Author Topic: CB500/4 cam removal (Read 6962 times)