81 head is off
 

Wanted to get the head and cylinder off the 81 CT110 stuck engine.

wanted to see the condition of the valves and if perhaps anything was in better condition than the 84 basket case parts...

Well I did manage to get the head and cylinder off...Cylinder is a definite write off...the head could be saved but the spark plug thread snapped, and the dowel pins that hold the rockers seem to be stuck to the rockers...so i can't pull them out to remove the valve springs... cam was a little crusty but could work in a pinch.

the timing chain side appear rust free...

The chain guide/idler pulley is like new so that's a part swap improvement.

looks like the same head stud is corroded worse than the 84. Seems to be a problematic stud location.

Refurbishing the CT110 84 head
 

Cleaned and lapped the original valves. They were in usable condition. Buying new valves cost more than I am prepared to pay for this project for now.

Invested in a cheap valve spring compressor.

Did a little porting while I had the opportunity.

Biggest problem is the spark plug doesn't seem to want to budge (I was using a 2ft breaker bar, but not applying to much force). I snapped the 81 plug in the head so id rather not repeat it...

Looks like a fairly new NGK and it does have spark...but not being able to remove it means making lean/rich carburetor adjustments will be difficult...

So the Conundrum now is do I leave it and run it as is knowing the plug could snap trying to remove it engine assembled...

Or do I try to remove it now and deal with the consequences while its on the bench?

Ive got the head upside down reassembled with penetrating fluid covering the spark plug so giving it 24hrs to maybe try a 2nd plug extraction...

Warm the area around the plug with a propane torch and melt a candle it will lube the threads and allow the plug to come out .

1 of the photos shows the head cooking on my butane camp stove...which will get it warm.

though I have been in need of a propane torch to add to the tool collection for some time.

Just an ordinary paraffin white wax candle right? because I also have my own beeswax...

Yes ,paraffin wax would work ,the camp stove should be ok too .

Just doing heat soak cycles with a heat gun and penetrating fluid 'with added ptfe' claims.

Will try to unplug the plug after 24hrs of soak time.

Postie Shade tree Chop Shop.
 

The 81 CT110 frame sacrifice to save the 84.

Both frames have some chassis blowouts.

As mentioned before the 84 has some hope left...

Just the messy rust discovery and removal phase.

Some blow outs are in similar trouble areas...but the main 84 problem spot can be cut out and patched.

Meanwhile..the 81 head is soaking in vinegar in an attempt to free up the rocker dowels and valves...

Unsieze The Day
 

Plug released its grip...

Cross threaded...quite badly. The thread tip of the extracted plug shows it started right at the tip all the way down.

I made a thread chaser out of a Chinese 'performance' sparkplug...So you can see what I think of its performance as a thread cleaner by making 2 disc cuts either side for swarf.

In other words don't get these orange 3 tip plugs...

Always start threading in spark plugs by hand people...

There must be enough material left to have some bind as a new NGK did seat with 1 half click of the wrist...

Glad I did it now while the head was on the bench as quite a bit of chewed thread material fell out of the spark plug hole...

This original Honda bike project is more of a personal shed/garage ornament and conversation starter, which I am just saving from a lost fate.

Yes I am trying to make it run. But replacement parts and maintenance make it expensive for long term on road viability.

Anyway If the plug holds I'll run it, if it ejects then I might think about helicoils and such...

Nicely done!

Some people shouldn't be allowed to touch tools.

Good on ya. I've had to make my own 'taps' when working in the field. Sometimes it's the only way when you're looking at effed up BSPP.

Does anyone know the part# for the 2 small return springs used inside the CDI timing advance assembly that is housed in the head attached to the cam timing gear?

Spring thing
 

Found the rusted timing advance unit in the bin from the 81 donor.

Thankfully it had the only still intact tension spring.

took measurements and order a pack of 10 stainless steel

20mm long 5mm outside diameter and 0.4mm thick wire tension springs

expected shipping from aliexpress is a month away. But finding a genuine OEM Honda replacement would cost 10x more.

Just needs to make the bike run...

Also having doubts about the JB case/thread repair holding the head and providing enough gasket clamp pressure...so I am making a decision to JBweld the head stud into the case...if i can find where i put the JB weld is the issue right now

This is normal. It gets worse. Like, “I just had that effing 8mm wrench in my hand.” Which is why I now pad time on repairs.

Got to many spinning plates half started now can't add any more or the whole lot could crash and leave a confusing mess...

Time to to to stop the spinning and rack things up.

81 engine further investigation
 

Removing the side cover of the 81 ct110 engine.

Had to cut off the welded on shift lever...

Inside found well established surface rust...I get the feeling this bike tried to be amphibious at some point in its life.

Though crunchy it all seems to be in place...and the case looks unmolested.

(unlike the 84...foreshadowing)

I don't have a 2 jaw fly wheel puller but in an attempt to remove the nut the engine did start to turn over albeit with the sound of some popular breakfast cereal. But the fact it turns suggests hope in a case split if ever required.