Honda-SOHC

Well done Mike always rewarding when you overcome such obstacles - the Cylinder head was a swine to remove on my 400.

As you have the engine out it should be easier to get releasing fluid everywhere before you start.
I have found you need plenty of time for such penetrants to soak through not a quick process.
It might be a consideration to look at ways you might be able to get gravity to help so that the weight of the head itself helps.
Just wondered is there is a way to support the engine upside down on wooden blocks or similar?

It's slightly different subject area - my carb sliders took well over 24 hours of petrol & other solvents to work in a closed container, all four of my carbs were stuck solid. The last one did not yield until three or four days believe it or not. The good news is new they eventually freed off without damage of any kind.

Maybe remove  the tappets and refit the covers minus o rings to give you another handy place to knock. Or if want replace them ( very cheap ) partially screw them in leaving a lip to drive against taking care to protect the valve cover edge. Haven’t tried this but it might be worth investigating.

For me the question is formost: can I indeed compensate the needles clip in 4th groove by adjusting the air screws to two turns out, like that American Honda specifications booklet suggests or should i return to the European set up with needles clip in 3rd? I have always had my doubts about that US booklet and I therefore volonteered to experiment.

Yes they sieze for a passtime, not sure if they can go all the way through either hole as never tried it, the always move eventually

Quote from: McCabe-Thiele (Ted) on April 26, 2024, 09:09:02 PM

Mine was fairly solid, might be worth tapping it back down where it is sligjhtly raised. I found my big rubber mallet worked making sure I  tapped it all round including some upper blows on the intake side.
I also sprayed WD40 type stuff all around the dealing area.

Thanks Ted. I have just given it another good squirting and a firmer tapping with a plastic headed mallet to no avail. I havent tried tapping upwards from the intake side; i will try that tomorrow morning after an overnight soak. Where did you bash it upwards on the intake side?

I can slide a polished paint scraper around between the castings to the right hand dowel but not the left hand one so I guess its seized on the left one. Im assuming the dowels are supposed to be locked into the head as opposed to the rocker housing?

I would tap it down on the side where you can get the scraper in AFTER squirting in releasing fluid then I tap it on the inlets first as close as possible to the head working along the four intakes - I used quite a big soft but weighty rubber mallet that I bought years ago at the centre Isle in Aldi. If you have a lead shot type mallet even better as there is no rebound. Also squirt plenty of releasing fluid down the dowel areas and bolt holes. A tap from the left and right side might help. If the front side is slightly raised keep it back down working more on the rear and sides. Cups of tea in between tapping sessions and light or medium blows should work - plenty of decent releasing fluid not standard WD4o helps. I used some  releasing fluid that car technicians use not bog standard WD40.