SOHC.co.uk Forums > CB750
Oil pressure issue / motor rebuild
MrDavo:
Out of sequence, as it's going back together now, but here's the layer of paint that killed the crank by stealing the clearance - I took this after scraping away half the paint off the journal, having softened it with the evil stripper, and yes, I was wearing a mask. I had to be very careful not to remove any alloy or otherwise b*gger up the original surface, but I think I did a good job.
Here's what was going on in the kitchen yesterday, while the wife was away, more gasket scraping going on here. The teaspoon made a good scraper for the carbon in the combustion chambers, after I softened it with the gasket remover. ;) Later I put the valves and springs back, after lapping them in. Ive still got to have a go at getting the oil jets out, or Trigger will tell me off, but then the head can go back on once they are cleaned out.
The genuine Honda head gasket just turned up from Holland, via UPS, in a huge box. As Trigger said, it's strangely sticky, but I've put it back in the packaging for now, as it looks very fragile around the middle camchain slot. I don't want to mess it up, I assume from the price it has a layer of 24 carat gold in the middle.
JamesH:
Yeah I've had 4 of the genuine Honda Head gaskets in as many months. Bloody bloody expensive....and bloody bloody sticky.
Bryanj:
Thats why they are a bugger to scrape off
Greebo:
Another very good tip for anyone doing a rebuild, or just doing any head work.
The genuine Honda rubber "O" rings in the head that create the oil seal were found to be to thin, hence many of these bikes had leaks from the head...to stop this happening you can buy the same Diameter O rings that are slightly thicker [1mm]
So that when you torque the head down it does create a proper seal where as the stock O rings did not , this was a fault Honda never cured or modified.
MrDavo:
Well, the motor went back in today, no pics yet until I'm on the desktop PC. :) the same two mates that helped me get it out came round, it was fairly straightforward. I won't get a chance to do any more till Sunday, my first priority is going to be getting oil pressure before carbs, pipes etc go on.
I'd had a drama with the ignition timing yesterday, the new Honda points on pots 2-3 would not gap small enough, and setting 1-4 correctly would not let me get the other pair opening properly. I remembered reading that there are two OEM suppliers, and wondered if I was mixing a backplate from one with points from the other. Anyhow I refitted the original points, which were in as new condition, and it timed up a dream! :)
Once I'd got the engine bolts done up and the oil filter on, I put her on the side stand (still an alarming angle) took the oil gallery plug out and squeezed half a litre of oil in. That will put some oil the crank's way and give me a head start filling the filter when I start kicking her over, once I have the tank and oil lines back in place. Of course the proof of the pudding will be getting the oil light to go out, then starting her for the first time. I remember how nervous I was firing up the Sportster after her crank change earlier this year, but once run in I set off for the North coast of Scotland, no worries.
It does look good, at least I've got a polished cam cover now, and some oil pressure, hopefully. Thanks to all that have helped, especially Ash and Graham.
Navigation
[0] Message Index
[#] Next page
[*] Previous page
Go to full version