New (to me) 40+

[skipper20]

Hello All, this weekend I purchased a 40 + engine #FP 106C0 in running condition for US$100. It's a perfect fit for the transom on my 12' SF Bay Pelican sailboat as I can leave the outboard bracket exactly where it is. The drive shaft tube is corroded, the tank needs a new filler cap and the spark plug is almost solid rust plus some of the exterior engine parts are corroded. It's not pretty but it starts and runs. Any suggestions on cleaning up the exterior corrosion? I suspect it's from being used in salt water. Re the drive shaft tube, I'm thinking of sanding it down and then spray painting it matte black. Is there a better way? I'll be using the motor mostly in salt water. I'd like to make it look decent but it doesn't have to look totally like new. TIA,

Bill in Seattle

[Liam2k3]

Re chrome would be the best protection against salt water but a good sanding and 2k prime and paint would resist the corrosion for a good while. Colour is up to you.

[Keith.P]

I would pull the leg and gearbox off, just to see if the bolts are not rusted up and how good the square drive is.
Normally if the drive tube is rusty, it's going to be pitted, if so just paint with hammerite or something.

[headdownarseup]

Worse still i've known the drive shaft (inside your rusty tube) snap in half from corrosion.
Well worth a quick look see for peace of mind.
It might give you a better idea over what the other components condition will be like.

Jon

[seagull101]

Im with Jon with this but personally i wouldn't paint the leg, every now and then a nice chrome leg comes up on ebay. keep your eyes peeled as it will only set you back maybe £20.

Jacob

[RickUK]

Sorry guys - no substitute for chrome plating on driveshaft legs - sorry because it ain't cheap or a quick turnaround! Even with chrome, it is still best to wash the leg after saltwater (or any) after use, and wipe over with an oily rag.

Drive shafts - I have seen some worn to a cloverleaf shape on the internal square at the gearbox end, presumably due to engine pulses, even to the point of fracture - no cure but to junk 'em.
In readiness for reassembly, I always cleaned rust of a drive shaft and sprayed it with Hammerite or similar, which also makes the fitting of an impeller more friendly.
Some oil down the internals might help in staving of corrosion, especially in the use we might give these motors, but I really don't know for sure.

Just to comment, most of the QB legs were plastic dipped - not powder coated, and were not perfect either, (a relatively soft surface subject to rough handling) but if powder coating today, one would have to compensate to get the correct diameter for an interference fit in the gearbox.

[RickUK]

PS - don't forget, if getting a drive tube re-plated, give the plater clear instructions not to touch the last 2 inches or so of the open end of the tube with a belt linisher or a buffing machine, as this will cause loss of the necessary interference fit in the water pump housing!!

[headdownarseup]

Something else i've noticed with many older seagulls and not just the 40 series either is that after extensive use the drive shaft can almost "swell" in size around the impeller and beyond. More than once i've seen impellers quite literally split in half whilst still fitted to the tube. They're only plastic after all.
I like to completely clear the inside of the square drive tube, free of all the blocked up goo that often collects in there after years and years. It's also a good time to look closely at how square each end of the tube internals now is. At this stage i've thrown away many drive shafts as they're too badly corroded or worn to do anything with. As Rick has mentioned, whether this wear is or was due to engine pulses, when coming to reassemble the lower unit back together there's often a lot of play when it's fitted onto the pinion shaft. Pinions (the square bit on the top) also wear because of these "pulses" if that's what we're calling it, and usually on the thrust side of each flat. Crankshafts show similar signs of wear too.

Flush after every time the motor has seen water tends to get thrown about quite a lot. Never a truer word said. A wipe with an oily rag or similar can only help in the long run.

Re-chroming drive legs is definitely the best way to go. Expensive to say the least, but if it's complete reliability you're after i wouldn't leave any stone unturned as you never truly know what's lurking a bit further inside.

Just my two penneth worth

Jon

[seagull101]

I too have seen impellers split, i always clean out the driveshafts and heavily grease each end with marine grade waterproof grease, i also paint my driveshafts.

Jacob

[Charles uk]

Drive shafts are now no longer available, so throwing one away might be a foolish course of action.

All Seagull drive shafts from 1942 to 1994 excluding the 5R & the Sport, have an internal dimension of 0.375" square.

Early Seagull drive shafts up to the mid to late 1950's didn't have hardened ends, sometime around this time Seagull started to Cyanide harden the last 4 inches of each end.

The usual method to repair rusty drive shafts is, on 64cc Seagulls 3/8" round hi-tensile bar is hammered/slid 2" down inside a 4" length of square drive shaft recycled from your rusty drive shaft tube, & brazed into place & quenched in water, this will harden the ends sufficiently, 102 cc Seagulls & Curlews normally get a half inch round bar turned down to 3/8" for 2 inches at each end, & brazed & quench hardened.

Sliding the new bar inside the box section keeps them straight.

Please don't forget to measure the total drive shaft length required before you chop out the good bits!

[headdownarseup]

What about if a good proportion of the tube is wafer thin and liable to twist, full of holes and the outer dimensions no longer correspond to anything like new let alone the inner dimensions actually being square any more. Trying to fit an impeller to a very knackered and rusty shaft like this simply doesn't work well enough to be considered a long term fix.
What would the headmaster do then? This is what i was describing when some of the tubes i've removed were nothing more than scrap and if you'd seen them Charles you'd understand why. I'm frugal not foolish.

Even with a length of round bar shoved inside them to keep them straight, they're now a bit heavier than they used to be. I personally don't like this idea despite having seen a few that have been repaired like this. I always like to try and find good second hand parts with little or no appreciable signs of wear for a rebuild. New when i can find them, but often second hand. Paint/protect them as i see fit.

0.375" square as an internal measurement yes, but some of the older tubes have a designed thinner walled section so the outer dimension is a little different compared to others, usually for bronze or alloy types of impellers. Some tubes it seems are plated as well. Plastic impellers on older tubes don't tend to fit very well. Very sloppy actually and prone to sliding up and down if not secured well. Trust me when i say i've seen plenty of bodges on a whole host of different seagulls before now.
I'd even go as far as to say i've seen drive shafts bodged up with araldite just to keep the impeller in place while the rest of the tube was almost rotten right through. What would headmaster do then? Probably the same as me which would be chuck it in the bin and start again with a better shaft.

Jon

[seagull101]

Drive shafts are now no longer available, so throwing one away might be a foolish course of action.

Don't Sheridan have them??

EDIT: https://www.sheridanmarine.com/product/ ... ive-shafts

[Charles uk]

Never seen one that bad Jon, rusty bottom end up to a third compromised, If your trying to fit a plastic impeller on an early drive shaft your making a beginners mistake.

I've been asked to tighten up on dreamy posts as I've had numerous comments regarding the site's creditability.

Currently the site is getting about 600 man hours per day from guests & about 24 hours from signed on members.

The guests can only be on here to find out Seagull data as we contain little else & we have a responsibility to keep everything posted as sensible & accurate as possible so that they have a worthwhile & rewarding visit!

Thanks Jacob your right once again! I think I'll have to offer you a job looking over my shoulder when I'm typing.

They must have found a source for the right size box after 2 years of unavailability.

Looks like I am one of the guilty parties!

[Keith.P]

Like Jon says, I have seen drive shafts that have pretty much rusted away and are no good to anyone, nether was the rest of the motor.
Seagulls are getting stripped for parts every day, as seen on Ebay, so drive shafts are not going to be a problem just yet.
Parts haven't been available for 40's and 50's motors for years, but we still find them.

[headdownarseup]

My point exactly Keith.
Thanks for that