Where should I start

[flyguy]

Thanks Keith, I double-checked the air vent and after reading more on here I tried the WD40 spray on the block but it didn't make any difference so I am hopeful it's not a cracked block or a loose gasket
I am going to take off the Carb and strip it down, fuel filter will be fitted as soon as it arrives

[flyguy]

Well I stripped down the Carb. it looked clean and I couldn't see anything amiss but I blasted it with Carb cleaner, left it to soak an hour in bits then put it in boiling water with some descaler then 90 minutes later I put it back together, I then rechecked the sparkplug and the gap was 22 thou so I reset it to 20 thou, I checked out the throttle, cleaned the lever and greased it up, its all back together with no parts left over
into the bin and I ran it without a hitch for 30 minutes PHEW

[flyguy]

I noticed when I took the carburettor apart that the screw that holds the needle was well down below level,
Does that sound right or should the screw head be level ?

[headdownarseup]

The little screw in the centre of the throttle slide is what adjusts the fuel mixture.
Ideally the screw (as a starting point) should be set flush with the top of the slide (standard factory setting).
Turning the screw down will start to weaken the mixture, BUT no more than 2 turns down from flush as the motor might be running a bit too lean.

When the motor is in the test bin,a good indication of how well the motor is running (and you will need the prop attached for this so you can put the engine under load)
at revs of around 1/3 throttle setting, there probably will be some "fourstroking" going on, this might clear as the revs increase past 1/2 to 3/4 throttle. If not then the mixture is too rich, turn the screw 1/2 turn at a time and try again until the engine runs sweet. (but no more than 2 turns on the little screw)
Turn off the engine and leave to cool down for an hour or so. Then go for a re-start, fingers crossed it will go first pull.Ambient temperature will have a lot to do with how easily an engine will start (or not in some cases) you'll get to know how much choke to use and for how long with practice.

keep at it, you'll get there

jon

[flyguy]

Thanks, Jon, that helps me, so as this is a 65 engine it should be using 10 to 1 and that is what I used and for that the screw should be flush I think.
this isn't mine its a picture elsewhere on SOS

Mine will be 2 or 3 turns further in
reading the FAQs it says that some pre 68 models "have been known to run on less than 10-1" is it likely that this lowering of the screw (further in) is a sign that whoever owned this before me was running a different mix from 10-1?
if so what signs would I see with the 10-1 mix I've been using?
if this lowering of the screw does mean it's been altered to a different mix I can experiment until I find a good fit between mix and setting
can I do that?
I will try that running with the prop attached first and see how I get on
Should I start by putting the screw back to flush?
I bet most of my questions seem daft to the experts

[Keith.P]

The adjustment will change over the life of the seagull and will depend on the motor, but it will have to be set with the prop on.

[headdownarseup]

There are many signs to look for.
A simple one is to look at the spark plug after the motor has had a long HARD run at high speed for 30 mins or so. Whip out the plug and see if the end is either wet with fuel or sooty black. Wet/oily is a rich mixture, clean and dry (possibly even a whiteish colour to the elctrode) might point towards a lean mixture.
Best way to tell is on the back of a boat,give the motor a run for 30 mins under load and then pull the plug out and have a look.
If the mixture setting is about right, there should be very little oil residue around the plug tip and a brownish colour to the electrode.

I've found a reasonable setting on the screw is about 1 1/2 turns down from flush, but as Keith has pointed out, as the motor gets a bit older and more worn the mixture settings will need playing with more frequently to acheive the best running characteristics.

Another sign to look for (if you've dissmantled the engine before) have a look at the piston crown for carbon deposits. (you could also see this by looking down the plug hole and the piston at TDC)
Cheaper quality oils will also produce a fair bit of soot and carbon over a longer period of time.
I use a semi synthetic 2 stroke oil (tcw2 or 3 or better) and find this to be very good with low levels of carbon and soot build up.

Experimentation is the way forward,as every seagull will be slightly different in one way or another. Start with the standard setting and go from there.
Yes it's true that several motors have been running for years at a weaker mixture with no real adverse effects, but err on the side of caution, small increments of change shouldn't do much harm. (dont go turning the screw down more than 3 turns max as it will be very lean at this point and run HOT)

Do you understand the term "fourstroking" as it will help you to determine what is happening with your motor with regards to a weak or rich mixture!

jon

[flyguy]

Thanks Keith and Jon, I didn't know anything about engines until I came here, but I am learning loads with all the help and advice, I hadn't heard of four-stroking but Google sorted that, I do know what it is now and I have heard it when the engine is idling so that will help me with the adjustments I make, I am happy enough to set it up with a 10-1 mix and once i'ts running really well I might see what it is like with a 15-1 but I am not looking to alter it to anything like 25-1, (however I can see me buying a newer model that runs 25-1 ) I do think the engine runs hot when compared with Seagulls I've used before, I will do all that I have been told to make this engine usable, its no fun having to row a mile and a half into a strong wind to get the boat back to the boat house, I've done that before
I looked at the spark plug and would say it was wet but not over sooty or oily
Next day off and I will be seeing what I can put into practice starting with 1 turn down of the screw
thanks again everyone, I hope to be sending you all some Trout later this year

[Keith.P]

The screw will make no difference if any to the low speed of the engine, only the top speed, basically under load.
The trick is to get the engine running evenly, you will see once you try adjusting it.

[headdownarseup]

Whereabouts do you fish "flyguy"?
It has been known on occasion for me to throw a bit of fluff and feather around!

6-7 weight rods mostly, but i'm looking for something a bit beefier for the pike fishing i'd like to do more of.

jon

[flyguy]

Hi Jon, I fish mainly in the North of Scotland for Trout, I go 4 or 5 weeks each year, I have a week in Caithness, a week in Wester Ross and a week near Lairg booked so far this year, I want the Seagull for Toftingall, Shin, Merkland, Fionn and then a week at Loch Na H oidche
the 7 weights should cope with Pike just fine and will be easier on the arm than a 9wt, I have a pal who fishes for Pike with a 5wt and does ok
I've only fished for pike a couple of times, my best were a couple at 5lb, too many teeth for my liking
I MOD on a fairly small forum called scottish-anglers.net a few of the members do a fair bit of Pike fishing

[flyguy]

The screw will make no difference if any to the low speed of the engine, only the top speed, basically under load.
The trick is to get the engine running evenly, you will see once you try adjusting it.

Thanks Keith, so putting the Prop back on and trying different screw settings I should get an idea of the best position,
so under load I'm looking for a smooth running engine when I push the throttle up and down?

[Keith.P]

Basically yes, you will find it may rev easier, but its more noticeable at top speed, it will either start to miss or four-stroke, you need it set between the two.

[flyguy]

One thing I havn't yet done is check the points so I read up on how to remove the flywheel cover and I know this will sound stupid but when I take off the flywheel nut will everything else stay in place?
I got a stand to put it on to keep it upright in the outside Cludgie

[flyguy]

Jon, Re. Pike on the fly
I got a call from some pals who are fishing in Wales this weekend
one of them got a 10lb Pike this afternoon on a Green Hopper, 6wt rod 6lb leader