Topic: removing stuck pistons, rotating engine to get cam loose,brake fluid

[crusierlover]

My manual is for the 79.It says use dot 3.I doubt that is made.I have dot 4, have seen dot 5.I heard dot 5 is only for newer bikes with certain pad material.The fluid has nothing to do with touching the disc, so dont know why it would matter.

I am going back as much original as i can on my z.But the rear signal lights are mounted to a nice luggage rack.It bolts to several places, is very sturdy.But I want clean.I am taking it off.Where were the rear signals mounted.The pics of z bikes have a rear tailight cowling with the tailight built in.But my aircleaner opens on the left, and the battery is on the right, all z trademarks.I am not going to waste time looking for a cowling.I have 3 sets of pipes.2 4 pipe sets, and the original 4 into 2.I posted pictures of the one header and muffler i took off last night.Totally utterly destroyed by rust.I think I can salvage 4 headers.Then somehow manage to get either 2 or 4 mufflers attached from somewhere.Maybe jc whitney megaphones.I dont want to spend 400 for a mac.

I was so happy to find the z seat and have it on.

One very smart member said to count on removing the head,  How will I get this engine torn down if the pistons rings are seized? Does partzilla or z1 enterprises or someone still make rings? With 17,000 miles i doubt it needs bored out.never used a micrometer.I see hones that mount to a drill.I guess you open it up to fit your bore then go up and down removing minimal material? Is the goal to create crosshatches? For new ring adhesion?I never once honed a motor on a truck or car. I could take the block to a machine shop, perhaps they would know how to hone a 37 year old jap motor.My manual says do not remove the carbon ridge at the top of the bores.Why? Why hone if one isnt going to do that?

Rotating the engine is necessary to get the cam loosened, to give slack to the chain.So the motor will not budge.So once i figure out how to get the head off,the the cylinder base , then the motor should turn over.Unless the gears are rusted and frozen, or the clutch discs are frozen together. That is why I am leaning towards engine #2 or # 3 to use.
  This is a pain in the ass, but I bought it messed up on purpose, to rebuild, to learn these bikes so I am  still really enjoying this.

[calj737]

Remove the spark plugs. Use a 50/50 mix of Acetone and ATF poured into the bores. Let soak. That concoction can eat the rust away if left long to allow you to rotate the crank.

To pull the head, follow the manual for proper sequence. But, be prepared to cut the cam chain (you need to replace it anyway) so you can fully remove the head. Then you can get better, direct access to the piston/bores to work on removing the rusted together parts.

Oh, by the way DOT3 is still readily available and interchangeable with systems that use DOT4.

[crusierlover]

I figure rather than cut the chain to get the head off or whatever else, like you said replace it anyway due to the rust,sitting for 12 years.Once I split the cases I may find I have a 150 pound paperweight.I am glad to have extra parts.If the atf acetone is used, which i am going to do, how much, about 2 ounces down each sparkplug hole? Even if the motor unlocks, many guys said here they did theirs that way, got the frozen pistons moving, rode several thousand more miles.I dont expect to be that lucky.If I rebuild and put all solid good parts I expect the motor to last indefinitely.I figure the primary chain is toast.It looks like an orange bar right now.No matter how long it soaked I wouldn trust it to rev up to speed and stay together.A masterlink chain is a easy replacement, and if the motor had no issues I would do that.But since this is a can of orange worms I intend once the cases are split to replace the cam chain,primary chain,rings,circlips,seals,o rings and all.This bike is not worth much even in pristine condition.But it is a great learning tool for me.I dont need this bike for a daily rider.I love its potential.

[calj737]

Any piston at TDC won't allow you you to fill the bore with more than an ounce or so. At BDC, you have some volume. Mix up a pint of each, pour it in until it back flows out the plug hole.

If you can release the pistons before disassembly, it will make further disassembly easier. If not, you'd have to remove the rod caps, then pull the jugs with the pistons in them, and knock them out afterwards. Endeavor to release them. With the head off, soaking and application of propane torch onto the cylinder walls will usually provide enough encouragement for you to rotate the motor with a breaker bar off the stator bolt.

[crusierlover]

Problem is whichever ones are at tdc or bdc is where they will stay until freed up.so 2 holes can hold a lot,2 can't

[calj737]

That is the dilemma. Shame they can't all stop mid way up... You'll find the bores at BDC are the stuck ones anyway. So they hold the most and need the most.

If you pull the head and can't get it unstuck, BBQ it (motor free from frame and away from anything combustible)

[SOHC4 Cafe Racer Fan]

That is the dilemma. Shame they can't all stop mid way up... You'll find the bores at BDC are the stuck ones anyway. So they hold the most and need the most.

If you pull the head and can't get it unstuck, BBQ it (motor free from frame and away from anything combustible)

Where are the smores?

[calj737]

LOL! I stood out in the cold for 4 hours keeping the fire burning after 6 months of soaking that thing off and on. It was middle of January, sleeting, blowing, and probably not much above 15*. I cuddled up to keep warm. No S'mores, but my coffee did stay warm 

[crusierlover]

um, may I ask....Are you guys kidding? You didnt do that to get the pistons unstuck for real did you? You just did it to get rid of it.Aluminum can never be used if its heated up that much.

The cylinder block feels like steel, the head and cases are aluminum.One might ask why not just go ahead and pull the engine now? Well, because being stuck has some advantages.If it were to break loose i can apply the brakes or pop it into gear to stop the engine turning over.This frozeness also helps break loose some of the larger bolts,rotor, etc. I really think the clutch is stuck, the primary chain is rusted like an iron bar, and the rings are stuck.2 of those are easy to remedy.

If I do have to trash a block I am going to get it sterile clean, then try to find plastic containers to fit each bore.Then at a backyard barbecue-this is texas-have one bore filled with my famous salsa,one with guacamole,one with barbecue sauce,one with frijoles.2 of my friends have entered and won prizes in cookoffs for beans and ribs.Combine that with shiner bock and country music, a few friends, you got yerself a shindig.

[calj737]

I am not kidding. And aluminum takes a lot of heat (+1,200*) before it melts. The fire is within the steel liners anyway. It doesn't get as hot as you think. Hopefully, such an effort won't be required on your end.

By the way, I used SeaFoam to BBQ my cylinders. It is flammable but doesn't have the same combustion behavior as fuel.

[754]

Cast iron liners,easy to replace. If you wreck one..
Just how hot did you think it would be getting when it is running?
Aluminum has some amazing properties sometimes..

[crusierlover]

I am not kidding. And aluminum takes a lot of heat (+1,200*) before it melts. The fire is within the steel liners anyway. It doesn't get as hot as you think. Hopefully, such an effort won't be required on your end.

By the way, I used SeaFoam to BBQ my cylinders. It is flammable but doesn't have the same combustion behavior as fuel.

yum.barbecued honda with seafoam sauce.

[crusierlover]

Cast iron liners,easy to replace. If you wreck one..
Just how hot did you think it would be getting when it is running?
Aluminum has some amazing properties sometimes..

  most bikes I have seen very few have thermometers, but usually the cylinders get about 450-500,not 1200. But,hopefully it wont come to that.One good thing today, my wife says if i can get rid of all the junk in the storage shed, which is a lot, i can use it for my shop.16x20 metal building with some shelves in there already.Quite motivating for me.

[crusierlover]

Just took a closer look at the license plate on the bike.I thought it said 04.Sat for 12 years.nope.It says 84.Sat for 23 years.Yep, I figger i will have a few parts rusted out.

[754]

Exhaust port is way over 1200 degrees, I think ... And piston crown near that..

[crusierlover]

Exhaust port is way over 1200 degrees, I think ... And piston crown near that..

wow.I had no idea.

[crusierlover]

Once I start taking this thing apart, it is crusted by decades of dirt and crud, what is best for some of the engine parts like the valve covers,center and right and left to soak in.Many articles I have read says after lapping valves, honing cylinders, etc clean in solvent.I am going to use berrymans on the carbs, but will chemtool clean junk off other parts without harming it.I know to avoid rubber, painted parts.Also, I do not particularly like painted engines.That is not original.I might change my mind after trying to refurbish some of this stuff.But on like the valve covers, engine cases, do ya'll take like mothers aluminum polish, hand rub it, use a polisher attached to a drill, or what?

[754]

If it's a cb 750 the crankcase, head and cylinder are all painted.. The outer covers are also fine brushed finish, and then clear coated..

[crusierlover]

If it's a cb 750 the crankcase, head and cylinder are all painted.. The outer covers are also fine brushed finish, and then clear coated..

no,mine is 79 650z

[crusierlover]

took the chain cover off, the primary sprocket, and inside the cover was 37 years of dirt and spiders nests.man this project is a huge one.

[crusierlover]

OK.Getting these carbs off has been a major pain so far.I have loosened all the screws in the clamps from the carbs to the head, and in the clamps on the back of the carbs between that and the airbox.The manual says slide the airbox back to give more room.After i disconnect the cables it does not look like the airbox is going to move anywhere.How much room are we talking about creating, an 1/8 inch?

[calj737]

If the bike is as old and neglected as you say, cut the boots between the carbs and head. Then do the same room carb to airbox. Just know that you'll have to replace them all.

[grcamna2]

I think removing all the clamps will help to get those boots to flex more if you decide not to cut the boots yet.

[crusierlover]

I think removing all the clamps will help to get those boots to flex more if you decide not to cut the boots yet.

the boots I can see look in very good condition.And they cost a lot.I am not going to cut them.

[rb550four]

Are you going to paint the frame ?  just asking... anyways,  the carb issue, You could take the battery box out ,remove the chrome half of the rear fender, then the shocks , lift it up then remove the inner rear fender and air filter box ,and then the carbs should have plenty of room .
  The rubber connections...You must back out the clamp screws  fully, put your finger on the backside of the screw to be sure they are unscrewed just ready to come out ( can't just loosen them  a little , won't work). hit them with a hair dryer on hot till they get soft...just a few minutes each and they should come off no problem. Use hairdryer again while re installing them and when re installing the carbs into them...way easier , less PITA , and the softened rubber probably won't tear.
  I use mothers for the shiny bits as a finish polish.  for the time encrusted bits  I use a soft wire wheel on a bench grinder to blow through years of oxidation first ,then use buffer wheels on a different bench grinder and use black,white and sometimes green  compound, I find the rouge to be greasy burns,and is harder to get off than the other polishes. Some guys use a bunch of different sand paper grades ...by hand then buff. I think life is too short to be doing that, but to each their own.  I have found that the 650 shiny bits especially up top don't polish as easy or as nice as let's say the 550 parts do . Don't know why , but they just don't buff out clean and is always lighter in luster.