S*** design or English simplicity?

[Dinghy fisherman]

Oh well, no turning back now as the tasteful tart up of one of my seagulls begins.
All going well with it not being in to bad condition considering its age with only problem so far. At the base of the gearbox housing, you know the bit, where the drive-shaft enters the gear box and exhaust outlet is; there are two screws. One is countersunk between exhaust and drive-shaft the other is a little easier to get at.

Im finding these are so tight with the position of the countersunk one making is so much harder to get at. With this in mind i removed the gearbox along with drive shaft still attached from the rest of the engine. This is now upturned in the vice allowing a 24hr soak in wd40 to penertrate the threads before i try and remove them. Both you and I know this is where the fun starts,right?

Heres a question for you: Is this English engineering simplicity or nothing more than a s*** design with other options being a better solution?

[headdownarseup]

Nothing wrong with the design DF.
Just years of neglect (and rust/corrosion) that's making things difficult to seperate.
Steel screws sitting in a cast aluminium housing, add into the mix some water and a few years and VOILA.

Heat from a plumbers blowtorch and NOT WELDING GEAR or you'll melt everything in sight (heat the bejeesus out of the pumphousing in the area of the screw, and give it a whack with an impact driver, but go carefully with the exhaust outlet when you're hitting the impact driver. Longer bits in the tool will overcome this problem.) normally works for me without too much grief. Never had one yet that i couldn't take apart. Worst case scenario, you may have to cut through the bolt/screw by going through the gasket that seperates the 2 halves of the gearbox unit. (messy and time consuming)
Once you've got it apart, clean everything including the threads (i use a thread chaser for this) and a touch of grease when you put it back together should make things a bit easier the next time it comes apart.

As you said, this is where the fun starts...... (or perhaps lots of cursing and swearing and the odd skinned knuckle just for good measure)
stick with it, it'll come apart

jon

[Dinghy fisherman]

Quote; Worst case scenario, you may have to cut through the bolt/screw by going through the gasket that seperates the 2 halves of the gearbox unit. (messy and time consuming) Unquote.

Thats a plan B I already have in mind I didn't think it was going to be anything but a battle of wills with something this old but to be honest, this is part of the fun of it all; isn't it?

One good bit of luck is the tube that the drive shaft passes down ( insert proper term here ____ ) which is chrome, had at some point been painted silver/grey. After a little elbow grease imagine my surprise to find the chrome in really good condition, no more grey paint going back on this. The drive shaft however is a hell of a mess, at first glance so a little more investigating and i will have a better picture of what's beyond repair.

Anyway, back to these bloody screws. Would bolts not have been a better option and would i be commiting a cardinal sin if i replaced them with stainless steel bolts?

[Horsley-Anarak]

S*** design.

They got it better with the later ones, Seagull 6 has big stainless bolts holding the gearbox on 13mm "af" heads.

Slotted head 1/4 B.S.F screw in an alloy recess, recess collects salt water, not great.

As Jon said give it some heat, I also punch the top of the screw with a steel drift, this does 2 things, shocks the corroded thread, and reshapes the slot so the screwdriver fits better.

H-A

[Adrian Dale]

Cut through the bolts as a very last option... this will leave you with the task of removing the remaining bolt by drilling. A very tricky task even with a machine vice and sturdy pedestal drill.

If you are tempted to head down this rout do not drill a small hole and attempt to use a stud extractor to remove the stump. This will expand the bolt and crack the housing.

Persevere with lots of heat. Take care to use a good, well fitting blade and minimise the damage to the screw head.

AJ

[Dinghy fisherman]

H-A and AJ.

Thanks for the advice and it will be taken on board. As for taking a hacksaw to the gear box screws, this will be my very last resort but one that may have to be done if all else fails. Im in a very fortunate position as i have a small workshop equipped with good machinery able to make such a job a lot more accurate in its application.
As for the tart up of this outboard time is on my side so theres no rush, im using my other one on my dinghy so i can take my time and hopefully do it justice in its finished condition.

DF

[haventaclue]

Drill the head off the screw.Cobalt bit the diameter of the screw straight down the middle,as it reaches the bottom of the head,it will spin off and when parted there is enough stem left to work with to get the remainder out.

[Collector Inspector]

Nothing wrong with the design DF.
Just years of neglect (and rust/corrosion) that's making things difficult to seperate.
Steel screws sitting in a cast aluminium housing, add into the mix some water and a few years and VOILA.

Heat from a plumbers blowtorch and NOT WELDING GEAR or you'll melt everything in sight (heat the bejeesus out of the pumphousing in the area of the screw, and give it a whack with an impact driver, but go carefully with the exhaust outlet when you're hitting the impact driver. Longer bits in the tool will overcome this problem.) normally works for me without too much grief. Never had one yet that i couldn't take apart. Worst case scenario, you may have to cut through the bolt/screw by going through the gasket that seperates the 2 halves of the gearbox unit. (messy and time consuming)
Once you've got it apart, clean everything including the threads (i use a thread chaser for this) and a touch of grease when you put it back together should make things a bit easier the next time it comes apart.

As you said, this is where the fun starts...... (or perhaps lots of cursing and swearing and the odd skinned knuckle just for good measure)
stick with it, it'll come apart

jon

Exactly what I wanted to say Jon!

Sadly everything else around me at that time got in the way aye.

Once sorted two screws are not a big deal anymore.

B

[headdownarseup]

Just had another quick look at your pics of the 2 motors.
Am i right in thinking you are working on the motor with the blue tank?

Looking a bit closer at the gearboxes (and also comparing what i've got in my shed) a later 40 minus that i've got with 1 water inlet slot, has allen bolts instead of slotted screws.Certainly makes things much easier to undo in the gearbox.

So in answer to your question, i wouldn't be offended if you put later stainless steel screws/allen bolts in your gearbox.

Drive shafts (the square hollow tube) seem to suffer quite badly with corrosion. (heard of 2 quite recently that have failed in service)
A little thing i like to do with them is clear out all the gunge from inside the tube then soak the inside of the tube with some waxoyl. Then the outside can be painted with appropriate paints. Should last for a few more years yet, provided it's not too badly corroded at the impeller end.

Alternatively, see if you can pick up another better example and use that.

any more pics?

jon

[Dinghy fisherman]

Hello jon

No its the other one that im having a look at. For the time being im leaving the one with the blue tank well alone as its running fine.
Using the engine identifier of this site im being told the one with the blue tank is a forty featherweight made in 1979 ( FS224AA9 )and the one im taking apart is also a forty featherweight made in 1973 ( F115HH3 ).
The one im working on has two slot heads and they look like they are original factory fitted items.

DF

[headdownarseup]

Ok , understood now

Use whatever fasteners you want, stainless steel will obviously last much better in the long run.
All in all, very common problems you are encountering here. (we've all been there at some point)
Heat the gearbox casing around the area of the screw (dont be afraid to give it "what for" either) and using an impact driver give it a hard whack.
Never usually gives me any trouble removing the screws this way, although there's always a first time.....

We've spoken many times on here the importance of HEAT when stripping down an old seagull that hasn't been apart in many years.
Most of the time ( not always) some heat carefully applied in the right areas helps quite a bit, especially with stubborn screws and bolts.
Think the gearboxes are difficult to strip down, wait till you have to remove a cylinder head bolt WITHOUT any heat. They'll just shear off...

These little motors are ruffty tuffty and will withstand quite a lot of abuse before they say enough is enough.

Keep going though, you're nearly there

jon

[polc1410]

Genius design

I'll bet no-ones ever had one of those screws come out while underway. The corrosion effectively creates a lock nut.

[Horsley-Anarak]

Genius design

I'll bet no-ones ever had one of those screws come out while underway. The corrosion effectively creates a lock nut.

I have lost the whole gearbox drive shaft every thing, wondered why motor was over revving.

H-A

[headdownarseup]

Not to mention a few early FV's that apperently "let go" in Poole in the early days. (not sure if that's a myth or fact)

But your right, the corrosion (whether you like it or not) actually does hold onto the bolts and everything else around it quite well for years.
Most (ahem) problems for want of a better word, seem to occur AFTER the motor has been completely dismantled and put back together?
I think it was Henry Ford that once said "if it aint broke,don't fix it"

I very nearly lost a gearbox from a 102 last year. It was only because the motor stopped pumping any water that i stopped the engine to have a look at what was going on... loose bolts almost at the end of their threads. (no thread locking compound)

No matter what now, i ALWAYS use some thread locking compound on bolts and screws just to be safe.

jon