Crank appears to be seized on a forty plus model??

[MorrisMan]

Thanks for the advice. I have left it all soaking for a few days and will then have another go after applying some heat to a few of the parts that have not freed up yet.

[MorrisMan]

I saw a secondhand crank in good condition for £15 so i purchased it. I think the original crank will be very difficult to reuse, not just as it is bent along its length, but also the end thread is sharply bent, and I may have to hacksaw the end off just to allow the flywheel to be removed.

My Bing carb is missing the choke flap and front airbox/cowling, any spares floating around for this carb?

[headdownarseup]

bing carbs are notriously known for dropping their inlet cowls (the square bit on the front of the carb?) choke levers break a LOT.

best advice is get yourself a replacement villiers carb, there's shed loads of them about and really simple to work on and clean. AND the best bit is it's a straight fit with no messing about.
The biggest problem with a lot of seagulls by now will be corrosion in one form or another. Some motors get affected worse than others.
You've probably guessed by now that these little engines will split down into 2 major sections
The powerhead
and the Lower unit
both of which can be stripped right down into component form (provided your lucky with the corrosion and are patient!)

Probably best to sort the engine side of things first before messing about with the gears below.

Your right of course to want to swap out the bent crank with something a bit straighter. These seagulls are quite tuff, but not that tuff.

Have a word with JOHN who runs this site, as he will more than likely have every part you could possibly need for these. (new and used at very reasonable prices)
and of course if ever you get stuck just ask one of us nutjobs as we've been there and done that MANY TIMES.

happy seagulling

jon

[MorrisMan]

Thanks John yes I think Villiers carb is the way to go. I hope to use the bing carb to try run it, and make sure the engine runs without major problems before spending more money on it.

I am a bit of an SU carb fan having restored them as a side income before, sadly the smallest SU I have seen is 7/8" and I don't know how well it would run.

[MorrisMan]

OK some pictures as I take it apart. First off lots of gearbox sludge:

Gearbox Sludge

And some parts that have arrived. replacement prop, spring, pull starter with dome nut, and D16 spark plug.

New Parts

I have heated a small protrusion in the gearbox housing that I assume contains the end of the countersunk screw inbetween the chrome poles. No luck yet. I have also heated the clamp part after removing the bolt. Should the lower half come free now, or do I need to undo the countersunk screw first?

Frozen screw

For now I have sprayed more release oil on the screw and the clamp part of the casting, and left it upright to hopefully soak downwards:

Stored

[Oyster 49]

Apply some heat to the area the screw locates and then fit the biggest screwdriver that will fit in the slot. Give the screwdriver a wack or three downwards and then use a spanner on the screwdriver (Square section screwdriver) to gently apply torque to try and unwind the screw. Take your time and keep applying plenty of heat.

Replace with allen screws! Good luck.

[headdownarseup]

I use an impact driver with a flat head scrwdriver bit after heating the gearbox casing. Usually works quite well, but there's always one that refuses to budge isn't there.

Heat and soak with some penetrating fluid and with a bit of luck the fluid will get drawn into the threads over time and help to release things to get them moving.
Allen screws are of course an option as a replacement (i prefer the original screws)
The contents of the gearbox looks fairly normal, sort of coffee coloured sludge is about right for oil that has emulsified over many hours use. BS reccomended every 10 hours or so between oil changes but these little engines are quite forgiving really. Just clean all the goo out and check for wear on the gears (fingers crossed it should be ok).

The villiers carbs are 1/2" and really very simple to work on (and there's loads of them about)

As for seperating the gearbox from the pumphousing it all relies on those 2 screws. The torque tube can be a challenge to remove from the pumphousing. I made a tool from some old dexion racking, the holes were quite conveniently placed apart to attach it to the top of the torque tube (where it would normally attach to the bottom of the crankcase) with 2 bolts. Apply some heat to the pumphousing and give it a twist backwards and forwards and eventually it should come out. (at this point you might want to place the pumphousing/torque tube in a vice but protect the aluminium casting with an old towel or similar) Normally works well for me.

best of luck

jon

[MorrisMan]

I had not realized that impact drivers start at only £10 or so - good enough for the job?

I put more heat on it today but still no movement, even with a socket handle attached to my screwdriver bit. Also my blowtorch keeps randomly cutting out even though it has a new gas cylinder. The end looks a bit rusty, I wonder if this is causing it to cut out.

[bikerboyfife]

To close to object mybe or trying to hard,,,,

[MorrisMan]

Well after more fighting with the screw I think I need to get hold of an impact driver, still no movement.

The replacement crankshaft arrived today, it came with a conrod attached and appears to be in very good condition. I will probably use this conrod, in case the one inside the engine currently is damaged/bent.

[Oyster 49]

If all else fails you can of course cut the two screws holding the gearbox on, by running a hacksaw along the gasket. If you do this just take your time..

[MorrisMan]

Bit of progress today, I found that with the piston at BDC I was able to pull the cylinder away from the crankcase, allowing me to separate the engine from the leg. Separating the cylinder from the exhaust tube was then easier.

Still no luck with the screw in the gearbox, but as the gears seem to turn ok I do not actually need to remove this to repair the engine. I will however need to remove the flywheel from the bent crankshaft. I have not been able to do this yet.

I found that I needed to heat the lower bearing to remove the bottom crankcase half.

My replacement crankshaft comes with a "SEAGULL 2" conrod, the one inside is a "SEAGULL 1". Is one preferred over the other?

crank case halves

lower half

[Keith.P]

If you need any help or parts, I'm just up the road from you.

[MorrisMan]

If you need any help or parts, I'm just up the road from you.

If you want to try and get the flywheel off after the Easter weekend I would be more than grateful for the extra pair of hands. The hammer I have is not really up to the job...

[Keith.P]

Copper, hide or rubber hammers that's not a problem, happy to help.