Saving Old Seagulls

Well I fired up this afternoon and she ran beautifully for ten minutes,all I did was tighten down the head bolts.So I'm thinking the overheat caused the head to expand a little.
Anyway she ran for ten minutes,then started blowing bubbles out the crankcase.So it's a strip down and rebuild.........again.Ah well better than a pile of scrap.
Oh I always use a bit more than 10:1 'till I get her running right,more like 8:1

New piston and block?

And one more

And more

Yes, I would say so, replacement parts would be the best way to go, its never going to run well in that condition.

Anyone along the M4 to Swansea from Bristol airport got one for sale,going that way 11th Nov. I see one from seagullrestorer so I'll hit the button,looks a little different to mine but it's for a 40+. Cheers.
These Gulls may be practicably indestructible but yours truly seems to have managed it.

You should be able to get that back and running with a bit of wet and dry sand paper!
I have seen a Lot worse than that!!!

Right then, now we can see what you have.
The piston should clean up nicely with some steel wool. (looks more like corrosion from where the motor has been left idle for ages instead of heat damage to me)
Piston rings should go again. Place just the rings inside the bore and measure the gap between each end of the ring to see how worn they are.
0.004 inch or 0.1mm is what you're after, any more and it will probably need new rings.

Small cylinder hones are always a problem to source.
Tip : I use a worn flapwheel (worn just enough for a snug fit inside the bore but not so tight that it won't spin by the use of an electric power drill)
A quick wizz up and down usually takes out the worst of it. (30 seconds usually is about right) I 've done this many times on 40 series blocks with no ill-effects at all. I'd almost go as far saying it's nearly as good as a purpose made cylinder hone but for a fraction of the cost. It even puts very fine scratch marks onto the surface of the bore which will help hold some oil while your rings are bedding in.

Suck it and see Noel.

It will fly again.

Jon

Firstly,Jon I hope that wasn't you I cut up at the roundabout coming off the M49 onto the A4 on Thursday evening Whoever it was,was very verbal
So I have used wet 'n' dry 600 to 1500 on piston and cyl,put it all back together,80psi,spark and fuel and she wants to run but,dumb dumb over tightened one of the head bolts,so I have two choices,take it all apart again and take it and get a helicoil,nowhere open 'til Monday,or tap insitu to M9 and blow through with air.
I have replaced the old bolts with new high tensile 5/16"BSF.But I am confident she will fly.

You're quite safe Noel, i don't go anywhere near the M49, so NO, it wasn't me!!! ( but there are some right eejyuts around at that time of day)

I told you these things are (almost) bulletproof. Tuff as old hobnail boots some of them.

I would keep looking for another cylinder and piston just in case though.

It'll go again, have a bit of faith. (plenty of oil with the fuel for the first tank full at say 8:1 then adjust to suit afterwards)

Jon

She flies again.Now all I need is a bit of decent weather to go for a wee spin. Thanks to all who gave me advice,encouragement and parts.Cheers

Yipee, smoke and noise. That's what we like...

any pics yet Noel of your maiden voyage with the gull?


Jon

Wet and windy for the last fortnight and any good days those chores that got put on the long finger had to be looked after,Yeah ,I think eighteen years waiting for the bedroom ceiling painted was long enough ,maybe before Christmas,weather permitting,and the silly season is almost upon us