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Discussion Starter #1
Looking for advice on the best approach to freeing up a frozen engine. Bought the bike to work on with my daughter. Before I spend any money on the restoration would like to get the piston unfrozen. When I removed the spark plugs there was water on both sides. The oil when drained also appeared to have water. My approach is to start putting marvel mystory oil and or wd40 in the spark plugs every day for the next several weeks and rock the bike in top gear. Is this a valid approach? Thanks
 

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Water in oil and cylinders? JMO, rebuild is in order, inside parts need to be inspected and cleaned/replaced
 

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Welcome to the forum. Your approach to freeing up the engine sounds like a good one. A freed up engine is easier to rebuild. Got any pics of it?
 

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Discussion Starter #4
Thanks Jim, Is it possible to get the engine apart without being able to rotate it to get the timing chain link aligned?
 

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I have not torn down one of my engines but I would think not. Like dtsmjr8dan said, a freed up engine is easier to disassemble. You still have the choice of finding another engine and just swapping but if you rebuild it yourself following the FSM and guidance on here, you not only know it was done right but you also know it will be reliable. Depends on what you will be doing with the bike. Flipping it? swap the engine. Keeping it to ride for years to come and then passing to your children and then grandchildren, rebuild it.
 

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Thanks Jim, Is it possible to get the engine apart without being able to rotate it to get the timing chain link aligned?
Yes. Just remove the cylinder head cover and cut a link out of the chain by grinding down a couple of rivet heads, or use a bicycle chain tool.

My CL175 engine turned over freely, but rusted bores made removal of the cylinders very difficult. Ended up having to split the cases and drift the pistons out. Piston rings were rusted into their lands, so replacement and rebore were required in any case.
 

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Discussion Starter #7
Thanks for the advice. I plan on keeping it so a rebuild of the engine will be my next task once I get the Pistons free. I have attached a picture of the bike.
 

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Very nice bike.
 

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Nice candidate for a good rider.
 

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I have had pretty good luck making a 50/50 mix of trans fluid and acetone, and filling the crankcase, and cylinders with it, with a heat lamp, or even a 100w bulb under the crankcase.. and just leave it for a few days.
 

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What Phil said, along with being patient, more gets damaged when you rush
 

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Discussion Starter #12
Progress has been slow but steady. Engine is apart and installed new pistons and rings two sizes up. I have ordered new valves. Once they arrive I will be ready to start the final assembly of the engine. There is one part that is confusing me. The Cylender Head schematic for the CB175k5 1971 shows four round rubber inserts under the cylender head. I did not see these when I pulled the cylender head off and do not see where they belong? Anyone have any ideas of what these are and where they go?

thanks Phillip
 

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Progress has been slow but steady. Engine is apart and installed new pistons and rings two sizes up. I have ordered new valves. Once they arrive I will be ready to start the final assembly of the engine. There is one part that is confusing me. The Cylender Head schematic for the CB175k5 1971 shows four round rubber inserts under the cylender head. I did not see these when I pulled the cylender head off and do not see where they belong? Anyone have any ideas of what these are and where they go?

thanks Phillip
I think youre looking at the vibration dampers that fit in between the fins in the head and stop them from setting up a harmonic frequency
 

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Discussion Starter #14
Thanks, I will take a closer look at the cylender head. Any idea where to look?
 
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