This 102 is no sucker!

[charlesp]

The serial would be good to have here. For a 1942 motor it'll start with SN or SD. That will give us confirmation wer're talking about the right thing. I don't know about the drop gauge, but I can tell you that the other charles is right. The HT lead should exit at around 3.30 to 4.o'clock when viewed with the plug at 12.00. That means with the tiller arm nearest you.

The exact timing isn't important; all we're doing here is trying to get the thing running.

I would be very surprised if this is a crankcase problem, but you can try feeding a little oil around the top bearing, that'll take up a little slack temporarily while starting.

A photo ofr the thing as it stands would help no end...

[twostrokenut]

At present this is a bit of a head scratcher , I would totally agree that the mains would have to have excessive wear in them to cause bad running , the most likely cause for this in older marine engines is long standing , allowing rust to build up on the crank journals , and then the usual "clean the points and give it a pull" , resulting in wearing the mains.
What I'm struggling to understand is that it "appears" to rev OK when oil is added , suggesting that the timing must be near correct.
I'm sure we will work together and get this problem sorted.

Andy.

[metalflake11]

Hello! You are all very kind with your time and sharing of your experience. SD 1581 is the serial number. I set the timing at 20 degrees B.T.D.C. which meant the baseplate locking screw was miles away from the locating hole....................................... and it started! It did all the things a Seagull should do (ie smoke and pump water) and some I don't think it should such as squirting water out of the two holes at the top of the drive leg! Well it ran for five minutes or so at medium to slow revs but when I tried to slow the engine down as you would to engage gear it petered out and would not restart. Off came the carb, blew out the jets replaced it but would only start with the drill after much rotation. I have tried to post pictures but this site says I have exeeded something or other and wont allow it. Well done all with your help!!

[Charles uk]

SD's normally have a bronze bush above the water pump impeller that should stop much water getting up the drive shaft tube to the holes you mentioned, the usual cause of water being forced up the drive shaft tube is, bronze bush missing & restrictions in the water jacket & the water delivery tube.

Your SD ignition coil is old enough to draw it's pension, If you read 40 tpi's posts on early ignition coil problems they mightwell paint a much better picture than I can about the problems, old coils are subject to.

[Hugz]

Re picture, you might need to use photobucket or similar and insert img number. Which points does it have... the original stud/nut or sliding screw type. Believe it or not I have a '42 that only starts with drill. Seem to recall that Charles advised point gap to be 10-12 thou on these. Dimple in the wrong place is strange unless it has been rebuilt with a later crank. All sounds very interesting.

[charlesp]

This is the motor in question, a nice sleepy SD from the later part of the production run, probably post war as it's a higher number than any I have recorded. I have one with a similar zinc coated block which had a similar tank transfer.

The magneto baseplate appears to be in the right place, and my suspicions now cast towards the coil and HT lead.

Have you another Seagull? Can you swap the whole magneto over; ie try another magneto on your SD and the SD's magneto on another Seagull? May be best to try a new (or known working) HT lead first!

As the other Charles says, the magneto is old enough to draw its pension, and we on this board are all aware thanks to 40TPI's diligent delvings that coils start to deteriorate the moment they're out of the factory. Even those which initially start after an honourable rest of a few decades may be so degraded that the burst of voltage through their frail windings is sufficient to render them useless. I have an OJ in the workshop that displayed exactly the symptoms you describe - a fresh coil sorted the problem. You will be aware that coils of this type are not currently available new, but a pair of sleeves can be had which would allow the use of the slightly smaller version used in the post-war Seagulls.

So I suggest a 'swap it out and see' approach.

[metalflake11]

Hello Hugz: I downloaded photobucket and after much frustration and time wasted I renamed it by replacing the b with a letter somewhere between e & g .......... It is stud/nut. If only they could speak what a story they would tell, mine has many brass, copper and bronze bits on it like the Navy type but is painted khaki which surely means army issue. More odd though is the tank decal which says British at the top but G.D.P. where it should say Seagull.....wierd!....... Hopefully the wonderfully well informed people on here have not got bored with this engine yet and will continue posting and with luck we may fix both of our venerable old 'Gulls. I do hope so as I intend to occasionally use mine as a backup in fresh water alternating it with my ultra modern '57 102 I always have trouble with those pesky dimples the other one has two of them!!

[metalflake11]

Charlesp: Thanks for the picture post! Yes, I have a small gathering of Seagulls in the garage and I will start to swop some bits around over the weekend. Sounds like a good plan! I am a bit surprised you think sd 1581 could be a post war engine, I believe the other Charles thought it was a very early one?! TTFN

[Charles uk]

That's my fault I gave Charlesp the wrong serial number.

[charlesp]

Well in all fairness if I had read the thread through I would have noticed!

So cancel what I said about post war, that is of course rubbish. It'll be 1942-1943...

[metalflake11]

Ah well! First time either of you have been wrong so far. I have removed a villiers MK2 from a '57 LLS and will try that tomorrow. I read 40 tpi's posts, amazing to think that the fine winding is just over 1 point 6 miles long isn't it? Changed a few bits around as Charlesp suggested but the only thing that made any difference was a thorough strip and clean of the carb. After that it started 1st PULL! yes, I said pull. After 5 minutes or so it petered out again and would not start for some while, it then started again after a few PULLS but petered out yet again. I wish somebody would have pointed out that the coil is old enough to claim it's bus pass ...........Joking aside, this all point towards a trip to the coil man for the baseplate and a thinning out of the wallet for me The proof is in the pudding though and I will let you know the results of the "new" ignition going on tomorrow........................Thanks to all again Rob

[metalflake11]

Hello all! Put the LLS magneto on and set the timing at 20 degrees before (different keyway so now at 10 o'clock rather than 3 30 ) and it started first pull, stopped it, started it again first pull. Let her get warm, stop start etc etc etc. The magnificence of it all!...........Thanks to all for the help and advice and especially to the two Charles'.................................................... Thankyou, this 102 is once again a sucker!!!!!

[Charles uk]

I think I can speak for the other Charles when I say

"it's good to see a plan come to fruition"!