Saving Old Seagulls

I'm currently trying to get FP I220J0 flying again.

For those that are interested - there are a few words and photos on the progress on my Website -

https://myshed.mooo.com/Seagull-FPI220J ... ation.html
This picture is of course prior to cleaning.

I got the little fella in OK - but non-running condition. Completely stripped it, cleaned it, bit of paint here, bit of polish there and it came up reasonably well, and fired up pretty much straight away - ran well. Ran it in the test tank a number of times for up to 10 minutes at a time.

Then I had to go away for work, and now that I've come home - it won't start - kinda sorta.

Here are a list of signs/symptoms.

• It will not start by pull start - Choke on or off - Throttle Full/Mid/Low

• It will not start by Spinning it high speed with a Power Drill

• It will start very easily by pull start if starter fluid/petrol is put in the spark plug hole

• It will start very easily by pull start if starter fluid is sprayed into the Carby intake

• Once it has started via starter fluid/petrol in cylinder, it will: run, and run quite well

• Once it has ran for a minute or so, it will start very easily by pull start

• Once it has been left to sit for more than about 2 hours, we go back to square one and it won't start.

• Very good, bright blue spark

• Timing seems good - locating screw is tightly in place

• Compression OK - 70psi

My thoughts - clearly a carby issue:

Disassembled and cleaned the carb (twice) - Blew Carby Cleaner through it - Ultrasonic Cleaner - Blew out with compressed air (its clean)

No change.

I can trace the fuel

• Comes out of the tank OK

• Comes out the carby end of the fuel hose OK

• Goes into the Carby OK

• With the float bowl off, I can see the fuel running into the Carby OK -Can start & Stop the flow with the Petrol Tap on the fuel tank

• Can also start and stop the flow by lifting the little lever the float lifts - so the needle and seat seem to be OK

• With the Float Bowl in place - when I hit the tickler button, I will see fuel overflow out the float bowl hole

Still not starting.

??Leaking Crankcase? No vacuum? Prior to assembly I flattened the mating surfaces with 400 grit Wet and Dry on a sheet of glass, they looked very good, but despite that, sealed them with an anaerobic gasket sealer. Would the engine run well once it was going if there was a crankcase leak?

Air Leak between Block and Carby? Is there supposed to be some kind of gasket/O-Ring/Washer in the Carby intake side that seals here?

My gut feel is that for some reason, there is a lack of vacuum which, when pull starting, the low speed of crank rotation isn't sucking enough fuel through the carby to start, but I gave it a good try with a Power Drill at good revs, but still no luck - so that theory is probably completely wrong.

I'm a bit stumped!!

I will try another carby if/when I get my hands on one.

What is this new way that bloody Seagulls can drive us crazy?

Suggestions welcome

Interesting one, are you using the correct fuel mix for the jet in your carb as some have been switched around?

Never-Outboard!! Brilliant!!!!

I have just come back to the computer after doing some more tests.....

I was feeling very pleased with myself for figuring out this issue - and as I was coming back to my computer I was thinking to myself - everyone on the forum will be well pleased with learning this - no-one will ever figure this out....

And lo and behold - there is just one reply - and never-outboard has hit it in one!

After my initial post I went back and looked at my Seagull sternly - muttered to it "We are not going to hurt each other are we?"

After having a think - I concluded its got to be fuel - nothing else - just fuel, so start at square one.

The fuel itself - its mixed at 10 to 1 and its reasonably fresh - maybe 5 months old at the most - more likely 3-4 months. I know old fuel can be a problem - not combustible enough to start/run the engine. But I don't think the fuel is old enough to cause dramas.

I also thought about the mix ratio - was there too much oil in the mix - thus making the fuel less combustible?

OK - what can I do about that? Off with the float bowl, empty the fuel out and fill it up manually with straight unleaded.

Screw the float bowl back on - pull - 3 pulls and she started right up!!

So - now I know its not the engine at all - its the fuel - which is a little embarrassing - a real rookie error - I just didn't think the fuel was old enough to be an issue....but it still may not be due to old fuel I guess - as never-outboard states - it may have already been converted to 25:1 and I am trying to run it at 10:1.

So to really isolate the cause - I will:

Pull out the needle and see if it has already been converted to 25:1

If yes - I will mix up some fresh 25:1 fuel and do a test - if it runs - the original issue was I was trying to run a 25:1 engine on 10:1 fuel
If no - I will mix up some fresh 10:1 fuel and do a test:
- if it runs - then the original not starting issue was probably due to old fuel (how embarrassing)
- if it doesn't run - back to square 1

No mention of cleaning & setting the points!

They were cleaned and set as part of the rebuild.

Producing a nice big fat spark.

More info:

The needle is No: 3 - ie: fuel ratio of 10:1

But when I pulled it out, I found the small Needle retaining screw set to 2 1/2 full turns below level with the top of the slide.

I assume that would set the mixture very lean - possibly too lean to start the engine??

Yep 2 and a 1/2 turns below will definitely not help! Make sure it’s flush with the slide, run it at 10 to 1 and you’ll be laughing.

Next time you reassemble a carb, use a screwdriver

I believe that once you have added two stroke oil to the fuel it degrades much faster than neat fuel. If that is true, then 10:1 mix must be worse than ever for rapid degradation.

However (there is always a however ) I have left 10:1 mix in both my Forty Plus motors for over 6 months and they have still started fine. Maybe different brands of fuel or oil "go off" quicker than others. In my case it is Texaco Unleaded plus Carlube 2-Stroke Marine Engine Oil.

Cheers, Mark

Degraded fuel would explain issues with starting and yet being able to run on its own once it’s going as well.

Well - I've got my answer - so r hubt of

Fresh fuel/oil mix at 10:1 and she's starting and running wonderfully.

The only other change was adjusting the carby needle retaining screw out 2 and 1/2 turns to sit flush with the top of the slide.

So it was old, degraded fuel.

How embarrassing.......