Topic: 1975 cb550 Mission ACCOMPLISHED! getting the motor to turn free from seize/stuck

[Stev-o]

Do not force! The case is made of soft aluminum and the threads can be damaged.
Did you compare the length of the new screw vs old? Sounds like too long.

[goldarrow]

The bolts kit came in with 2 long bolts. One goes in on the right side of the cover, and it goes in just fine. The other one goes to the top of the cover by the clutch lever, but it won't go all the way in. Could it be that old screw broke off with the tip stuck inside?

I put the new long bolt next to the hole to compare against the hole and seems like the length is fine.

7 of the original screws were missing, including the 2 long ones, from the bike so I couldn't compare.

[rb550four]

Those new bolts come in 5mm increments try a smaller one, hand tighten it last so you don't strip the threads if there was previous damage. Or don't because you'll be taking it off soon, nothing obviously wrong in there, so there will be a problem elsewhere. If your oil pan is totally empty remove the 10 bolts on the pan, have a receptical beneath it should there be drippage. It's flashlight time. You will be looking for the center of the crankshaft for a small chain, it shouldn't be in a heap  on the bottom. It should be endless encompassing the crankshaft and cam. While you're there, checkout the primary drive chain for slack gear to gear and side to side ,then everything around it for damage. Take a look in the pan ,any parts? Is there metal filings or chips ? you are looking for signs of major wear or failure such as ring parts,broken gears, burned bearings...make sure the bike is on it's side or that someone strong is stabilizing it on the centerstand, it's still 500lbs. if it falls on you. Good hunting.

[goldarrow]

Got some more time to play with the bike again today. Enjoying every minutes of it.

Well, my goal for today was to remove oil pan and cam shaft cover.  Not successful. Quite a few pieces of oil pan bolts were rusted and stuck pretty tight. So I tried to remove the top cam cover, same thing, rusted screws stuck really good. I didn't want to strip the head, so I kept moving on to remove the next piece whatever I could remove.

So, exhaust was next. Right exhaust was blocking access to oil pan, so this has to come off and successfully. I looked inside the exhaust hole #3 and #4 they looked bad

Am in pretty much on a mission to rebuild motor?

My two kids helping me out with the bike

[goldarrow]

Those new bolts come in 5mm increments try a smaller one, hand tighten it last so you don't strip the threads if there was previous damage.

I used a washer to fill the gap, it's ok now. Good temp fix?

[rb550four]

Good temp fix, cute kids, and yes , I think that this engine will have to be rebuilt especially if you want to give a running machine to your oldest son in 12 years.

[Stev-o]

Do you have an impact driver?

[goldarrow]

Yes I do but already smashed/shattered two bits. Have to get new bits

[Stev-o]

Yes I do but already smashed/shattered two bits. Have to get new bits

WOW.  You'll need impact rated bits.

[goldarrow]

Good temp fix, cute kids, and yes , I think that this engine will have to be rebuilt especially if you want to give a running machine to your oldest son in 12 years.

now i think i want to go frame off restore route, should i start disambling the bike?  or should i still try to get the engine rebuild first?

i could probably try to get car battery to connect and check some electrical stuffs during the week

[rb550four]

Disassemble . You'll have allot of bike apart just to get the engine out.
  Do you have an impact screwdriver for those stubborn case and head screws? Harbor Freight has them cheap but the bits are crap, NAPA is expensive, some of the other auto parts stores may have a decent one at a reasonable price. see if they sell bits separately for later on, you 'll need them ( the big Phillips head). also ,some come in 3/8"drive and some are 1/2" drive, it only matters if you want to use it with your impact sockets.
 Ziplock freezer bags and a good marker to id pieces, take pictures as you remove parts, so you know how it's supposed to look as you reassemble and we can watch your progress.
  What do you want to tackle first, engine  or everything else? You can remove the top end and find out what's going on, it'll make it lighter for removal. Rebuild it so you know it's all good then either stuff it back in the frame and keep it original (then you could ride it )or go all out on the rest of it (takes time+ $ from the family), Your little guys won't be little guys long, you may want to plan a father and sons restoration when they get to the defiant age, where they need more of your time and attention, but don't know how to ask for it. They will have lifelong memories of building these machines with Dad, and appreciate them.
   Get them interested in the engine , then the ride, the rebuilds as they get older. Double legacy. You 're a good Dad.

[Stev-o]

I'd get the motor free first, it will be even more difficult if it is not mounted.
Most likely, the rings are to the cylinder wall. Have you been putting more acetone/ATF in it? The acetone evaporates very quickly.

[goldarrow]

Your little guys won't be little guys long, you may want to plan a father and sons restoration when they get to the defiant age, where they need more of your time and attention, but don't know how to ask for it. They will have lifelong memories of building these machines with Dad, and appreciate them.
   Get them interested in the engine , then the ride, the rebuilds as they get older. Double legacy. You 're a good Dad.

rb550four,  thanks for the word of encouragements.  i lack this when i was growing up and now trying to make up for it. 

i'm gonna go all out and start the bike fresh - take them off and clean them, buying new parts when the time comes or ready to put them back.

but at the moment, my goal is to take those stubborn nuts/bolts/screws off and it will be paint stakingly slow process.  parts on the bikes seem to be fairly straight forward to take them off if not stuck/rusted

will sure post more updates.  here's my shopping list for now - i know they're expensive, and no i'm not rich, i just figure that they would last me longer than many other cheaper tools out there
some sears craftsman tools are on sale at the moment - any thought on these?

http://www.sears.com/shc/s/ShoppingCartDisplayCmd?partNumbers=00966196000&orderId=349597209&appID=&storeId=10153&langId=-1&catalogId=12605&cartOmnitureFlag=Y&fromPage=ShoppingCart&productId=40468781&isCartValidated=true&calculationUsageId=-1&searsRnpEnabled=false&storeName=Sears&updatePrices=1

[lone*X]

Just quickly read through your thread so I may have missed this but have you removed the alternator cover and tried turning the engine over with a 14mm socket wrench on the rotor bolt?  Rocking will work many times, but a stubbornly stuck engine may require a little more torque than you are applying by rocking.  This actually would be my first step if trying to break one free.  Its worked for a lot of members.  I have a couple of motors pickled and under the work bench.  Both have the alternator covers off so I can turn them over once every month or so

[goldarrow]

Just quickly read through your thread so I may have missed this but have you removed the alternator cover and tried turning the engine over with a 14mm socket wrench on the rotor bolt?  Rocking will work many times, but a stubbornly stuck engine may require a little more torque than you are applying by rocking. 

thank you for your suggestion - i was considering doing that but have not done so because
- i was having the impression that make sure the cam chain and primary chain are not broken, so this require dropping oil pan and remove top covers, but now having situation with rusted nuts/bolts/screws
- i took pictures of inside spark plug holes #3 and #4 (pics above) and they looks pretty bad.  could i have break them if i rock the bike too hard?  that's why no wrench on the rotor

[lone*X]

I wouldn't think the cam chain is in any danger.  The 14mm bolt screws directly into the crank end.  It is not going to turn anything else until after the pistons break free.  If you get it free just remove the valve caps and look for movement in the valve adjusters.  If the transmission is locked for some reason the primary chain will take all the torque and believe me, you are not going to hurt it using a standard ratchet.  Just don't put a cheater on the wrench.

[mono]

nice bike!  i've got one of it's twins!

being a 1st-timer at all of this also, my suggestion would be to leave the bike as intact as possible while you deal with your engine problem, since your 1st order of business is going to be getting it running.  after it's running you'll be able to determine what else is wrong with it, which you can't really do if it's in a million pieces.

but that's just my novice opinion - others?

[goldarrow]

I wouldn't think the cam chain is in any danger.  The 14mm bolt screws directly into the crank end.  It is not going to turn anything else until after the pistons break free.  If you get it free just remove the valve caps and look for movement in the valve adjusters.  If the transmission is locked for some reason the primary chain will take all the torque and believe me, you are not going to hurt it using a standard ratchet.  Just don't put a cheater on the wrench.

over the weekend, i took the rotor cover off, wrenching the bolt with wrench, still no go on the motor.

[goldarrow]

I'd get the motor free first, it will be even more difficult if it is not mounted.
Most likely, the rings are to the cylinder wall. Have you been putting more acetone/ATF in it? The acetone evaporates very quickly.

ATF+acetone in to the cylinders, left it over night.  looked in the cylinders the next day, still see some atf/acetone in #2 and #3, but none in #1 and #4,  motor still no go when wrenching at the rotor

[lone*X]

Sounds like it is time to pull the motor. remove the head, and work from inside the cylinders.  With the head off you can take a short piece of soft pine lumber, a 2x2 works well, and use it as a soft drift and whack the piston tops using a dead blow hammer.  At this point you probably are not going to hurt anything any worse than it already is.

[Stev-o]

I'd get the motor free first, it will be even more difficult if it is not mounted.
Most likely, the rings are to the cylinder wall. Have you been putting more acetone/ATF in it? The acetone evaporates very quickly.

ATF+acetone in to the cylinders, left it over night.  looked in the cylinders the next day, still see some atf/acetone in #2 and #3, but none in #1 and #4,  motor still no go when wrenching at the rotor

You need to add more every few days or so. The acetone evaporates quickly. This method worked for me...

[goldarrow]

Those new bolts come in 5mm increments try a smaller one, hand tighten it last so you don't strip the threads if there was previous damage. Or don't because you'll be taking it off soon, nothing obviously wrong in there, so there will be a problem elsewhere. If your oil pan is totally empty remove the 10 bolts on the pan, have a receptical beneath it should there be drippage. It's flashlight time. You will be looking for the center of the crankshaft for a small chain, it shouldn't be in a heap  on the bottom. It should be endless encompassing the crankshaft and cam. While you're there, checkout the primary drive chain for slack gear to gear and side to side ,then everything around it for damage. Take a look in the pan ,any parts? Is there metal filings or chips ? you are looking for signs of major wear or failure such as ring parts,broken gears, burned bearings...make sure the bike is on it's side or that someone strong is stabilizing it on the centerstand, it's still 500lbs. if it falls on you. Good hunting.

just finally got a chance to drop oil pan and inspect the bottom.  everything looks ok in there.  no metal parts or anything in the pan.  the primary chain has slight slack that i can push with my finger a little to go up and down.   

i think i'm on a journey to take the top off soon

[goldarrow]

Sounds like it is time to pull the motor. remove the head, and work from inside the cylinders.  With the head off you can take a short piece of soft pine lumber, a 2x2 works well, and use it as a soft drift and whack the piston tops using a dead blow hammer.  At this point you probably are not going to hurt anything any worse than it already is.

Cam cover is removed and I think now I have another problem. 2 bolts holding the sprocket, but only one is exposed at the top, and I act turn it because of the seized pistons. What do I do now?

Also the cam shaft and rocker arm will need to be replaced?

[rb550four]

 
   You're a patient man, you've done everything a reasonable man would do with no success. Now it's time to take top end of that motor out of there and see why for.
   The motorcycle may seem magical and mysterious but really it's a machine. It's a machine like 200,000 other ones and has no will of it's own.  You are the owner, the master of this machine, armed with a shop manual ,tools and perseverance. Success may not come easy but it can be accomplished. Keep us updated.

[rb550four]

Some guys grind down a 10mm wrench and go after the bolt, then find that the bolt is longer than they thought, and mess up the inside of the shaft. I just cut a link and buy a new chain. Once the chain is disconnected you are able to take it all apart...no headache... no foolin around, get right to work. Chain around $125 cheaper one with link on Ebay.