Topic: RE: Look what I got for $100 today

[chewbacca5000]

Ok got the shift cover off got it in to neutral and no love.  This engine is definitely stuck.  I am going to try and take the top end off and see how bad the damage is.  Build thread on the way.

[Stev-o]

I unstuck a K7 with the acetone/ATF trick.

[chewbacca5000]

I unstuck a K7 with the acetone/ATF trick.

Did you get compression on all 4 cylinders after?  Seems like alot of the bikes I come across have at least one rings stuck to one piston.

[Mo]

Meh it's really too hard to tell if compression is going to be good or bad at this stage. Let it soak in ATF/Acetone for a week, adding a little bit more each day. If the pistons are stuck to the cylinder, this should free them up.

If that doesn't work, a top end job isn't too hard. Just takes time/patience and from experience (double/triple checking your work).

Geez pine needles in the spark holes!

[chewbacca5000]

Meh it's really too hard to tell if compression is going to be good or bad at this stage. Let it soak in ATF/Acetone for a week, adding a little bit more each day. If the pistons are stuck to the cylinder, this should free them up.

If that doesn't work, a top end job isn't too hard. Just takes time/patience and from experience (double/triple checking your work).

Geez pine needles in the spark holes!

We'll I could not quite wait for a long soak so I opted for the grease gun method only to find out that number 4 exhaust valve is stuck and won't move.  Probably was left open.  Man I wish I had remembered to check this before packing cylinder 1 with grease.  After it started pouring out the head gasket I found the problem with the valve.

Now I just got find out how to unstick the exhaust valve and the engine may turn afterwords.  I am still going to tear it down just want to get this valve free.  As for the grease gun I think it would have done the trick if it was not for the valve.

[jamesbekman]

Kroil is your friend.

[iron_worker]

If it came out of the head gasket like that it was probably blown anyway.

Also, if the valve was stuck on one cylinder you could have tried on another cylinder. Personally, I would be pulling the head off. Running an engine that was previously seized just seems like a really bad idea. The rings are likely stuck and the bores will be completely filled with crap and will cause a huge amount of wear that's not necessary.

IW

[chewbacca5000]

If it came out of the head gasket like that it was probably blown anyway.

Also, if the valve was stuck on one cylinder you could have tried on another cylinder. Personally, I would be pulling the head off. Running an engine that was previously seized just seems like a really bad idea. The rings are likely stuck and the bores will be completely filled with crap and will cause a huge amount of wear that's not necessary.

IW

I tried to take the head off but I can't get to the lower cam bolt without splitting the cases or cutting the cam chain.

Does not matter anyway as I am getting a new engine from a 73 550.  Local guy is going to help me out.  Only 8000 miles and the engine turns over.  Splitting the cases is more than I wanted to get into one this one.

[chickenman_26]

Right now I am wiped so my only project will be de sapping and taking needles out the spark plug holes tonight and getting some spray down there.  I know about all the receipes ATF/ Acetone, PB blaster / Seafoam.  I will try an get some stuff in there and let it soak before forcing anything.

I understand you and your friend would like to have some fun exploring the possibilities. But as the resident naysayer/curmudgeon/realist around here, I'd counsel you that unless you're willing to commit a minimum of $1,500, you should part that bike on ebay and pocket a few bucks. If you start replacing parts before making an accurate assessment of what's needed, you'll be totally upside down before you're even close to getting that thing on the road. My hunch is that every single piece of it needs to be replaced, repaired, or refurbished. It adds up fast.

Stu

[chewbacca5000]

Right now I am wiped so my only project will be de sapping and taking needles out the spark plug holes tonight and getting some spray down there.  I know about all the receipes ATF/ Acetone, PB blaster / Seafoam.  I will try an get some stuff in there and let it soak before forcing anything.

I understand you and your friend would like to have some fun exploring the possibilities. But as the resident naysayer/curmudgeon/realist around here, I'd counsel you that unless you're willing to commit a minimum of $1,500, you should part that bike on ebay and pocket a few bucks. If you start replacing parts before making an accurate assessment of what's needed, you'll be totally upside down before you're even close to getting that thing on the road. My hunch is that every single piece of it needs to be replaced, repaired, or refurbished. It adds up fast.

Stu

Stu your right it would probablly cost 1,500 to get it back to like new condition.  My plans are to get it running for with save tires for $500.  Should be doable.

[Powderman]

I think I have to disagree with this. When I got my bike, I too thought it was "stuck". Took the chain off, and tried to kick it over with no luck. It wasn't until I got it into neutral by hand at the front driven sprocket was I able to kick it over.

Just for kicks and giggles, before you do try to free it up, put some ATF/Acetone or PB Blaster in each of the cylinders. A bike that been sitting for long will most likely have some moisture or be very dry so the oil will be good to prevent any damage (even if not stuck).

I was very concerned with rusted dry cylinders on my motor that sat for 35 years. It was a fresh complete build in 1977 and never had any oil in it. I thought the rings would be rusted to the bores and the walls would be rusted after sitting for 35 years. I pulled a plug and stuck a bore scope in it and was absolutely amazed at what I saw in there. You could see fresh crosshatch honing like it was done yesterday. Squirted some oil in and it turned over easily. Maybe I got lucky.

[Stev-o]

Dropping a 550 in it sounds like a great idea.

[chewbacca5000]

Dropping a 550 in it sounds like a great idea.

I found a local CB550 supplier has as much 550 stuff as I have 750 stuff!

[Stev-o]

I like the 550's nearly as much as the 750's...

[chewbacca5000]

I like the 550's nearly as much as the 750's...

You can work on the top end without taking the head off.  No oil tank too.

[knobbs]

My local breaker has prob 6 tanks for that bike in good shape if you need me to enquirs , when you get that far.
Knobbs

[chewbacca5000]

My local breaker has prob 6 tanks for that bike in good shape if you need me to enquirs , when you get that far.
Knobbs

Much Thanks!  I will probably need some tank help mine is badly rusted with holes.  Thanks.

[chewbacca5000]

Hey guys check out my CB500 build thread. 

http://forums.sohc4.net/index.php?topic=120606.msg1365558#msg1365558