http://sohc4.us - the Honda SOHC 4 (Single OverHead Cam) owners website, a veritable treasure trove of fixes and tweaks and maintenance tips for these machines. I finally decided to go with the "pour WD40 down the spark plug holes and leave to sit for a few days" method as it is more than likely that the pistons are stuck to the cylinder walls by rust. The bike has not likely run since 1998 (the last year it got a warrant of fitness - WOF - 7 years ago) so it could well be rusted.

Whilst waiting for the WD40 to work it's magic, I began to dismantle the bike. My intention is to strip it completely down to the frame and repair, replace, or clean up, everything dependent upon what is required. I'm not out to create a pristine example, just a nice and tidy bike to ride and enjoy...
So, things go fairly smoothly until it is time to dismantle the brakes - the pistons are well and truly rusted into the calipers and won't budge - tried to use air pressure to no avail (a suggestion on the tech forum SOHC4 website) until I came across the advice to just hook the caliper back up to the master cylinder and pump, pump. pump until the piston pops out... worked a treat! Sometimes the simplest solutions are the best....

The rear brake pads are unfortunately had it, worn down to the metal backing, which might just explain the rather severe groove marks on the rear disk... the front pads are ok and will go back on at this stage.

4/7/05 – Dismantling & Engine "freeing up"

Removed the oil filter and drained the sump of oil - did I say oil? Brownish white sludge would be more of an apt description! Immediately upon removing the sump plug the first fluid to appear was a substantial amount of what I assume was all the WD40 I have sprayed in via the spark plug holes! (yellow brown & thin). This makes me reconsider what could be the likely cause of the "lock up". If the WD40 has made it past the piston rings to the sump......?

Periodically I am trying to turn the engine over via the kick start lever..... still no movement as yet....   :-(

Came across a posting on the SOHC4 site recommending removing the alternator casing and swinging on the nut on the end of the drive shaft to try turning the motor over… figured I would give this a go, so I removed the cover and decided instead to slide a largish screwdriver through the stator and to tap on it (the screwdriver) with a hammer… it moved ever so slightly! Tapped in the opposite direction, and yes, indeed things were moving! I attached a 19mm socket on the end nut and turned things at least half a turn. Success! Turned it over a few times and thought I could hear WD40 in the cylinders sloshing around – went around to the kick start lever and swung on it..... great! Seems that the engine is now freed!

The engine was successfully removed today – I followed the formula laid out by a contributor to the SOHC4 forum "Kaceyf2" who recommends using stacks of old magazines to "slide" the engine out of the frame… this worked rather well with the help of my long suffering wife!

The lump!	A brighter view	From the carbs view	Engine number

1/8/05 – Final Disassembly

Bare frame	Totally bare!
Stripped to the metal	From the front

Since the engine is now out, I decided to remove the starter motor to inspect it's overall condition and function. What a job to get it removed! It was well and truly rusted in! This, I now believe, was the reason for the engine being "locked" up.... the output shaft from the starter motor was rusted to the crankcases and to the motor body itself! There had, in all likelihood, never been anything wrong with the pistons... when removing the alternator cover earlier it was necessary to remove the cogs which connect the starter motor to the crank thus releasing the engine from the starter motor proper, allowing it to turn over! After some judicious soaking in CRC and removal of all rust, I attached a set of jumper leads from a battery to the starter motor and was rewarded with a satisfying high pitched electric motor whine. It would appear that the starter motor is all good now!