Running problems after rebuild

[FoxUk]

Over the winter I bought another spares featherlight and using this one with my working one stripped both down and took the best parts from the two.

I clean every part and replaced stuff like piston rings and gaskets and made one good engine! However I use the word 'good' loosely

The nice new looking engine starts fine after a few pulls but a few minutes into the run it stops! It also appears to be lacking in power! At first I thought... fuel starvation (a bit of priming etc and I can get it to start again) but I've stripped the villars carb down and fuels pipes... all look good.

When it does run, the revs appear to go up and down but no misfiring or spluttering. Also... a little strange but i'm sure it starts better with the choke out instead of in! (but might just be the warm weather this weekend).

Any ideas? I did take everything apart during the rebuild including the crankcase but I used gasket sealant to put it back together again.

I would be grateful of any pointers.

Cheers

Paul

[Horsley-Anarak]

Hi Paul, and welcome to the forum.

Post a few pictures so we can see what it looks like, makes diagnosis easier, ignition type etc.

Do you still have a spark after the engine stops?

H-A

[FoxUk]

Hi... These are some pics with the engine in bits so you can see what parts I used.

The spark looks good even after the engine stops. I think the (going by how the original engine ran) engine never gets up to full power although at the weekend I did get it pushing my kayak in the local loch for nearly five minutes before it slowly died! By the time I paddled to shore reprimed the carb it started up again but then died shortly afterwards!

It feels like a fuel problem but I've checked the carb, tank and fuel line many times and it all looks OK.

Any suggestions appreciated...
Cheers
Paul

[Horsley-Anarak]

Does sound like a fuel problem, run it in a bin, as it starts to die, give it a squirt of WD40 throught the carb, if it picks up then you know it is fuel starvation.

Have to checked the compression, did you use a new head gasket?

H-A

[Oyster 49]

Have you checked the fuel tap has a steady fuel flow when it is pulled on? The tap can become partially blocked, which will allow the float bowl to fill, but maybe then not enough flow to keep the bowl topped up.

Also, how much fuel are you putting in the tank? A full tank will of course have a bit more delivery pressure!

[FoxUk]

Hello... thanks for your replies.

There is fuel coming out of the tap but it's more like a dribble than a full flow. I wasn't sure if this was normal. However your comments have got me thinking... I guess if there isn't enough fuel getting to the carb, once the engine dies I could unscrew the carb bowl and check if it has any fuel in it.

I have been wondering if it was a compression issue but I don't have one of those compression tester thingy with a gauge. Maybe time to buy one.

Cheers

Paul

[Mike Killay]

Try without the petrol cap. Could be the cap valve, sounds like a problem I once had.

[headdownarseup]

With most "old" engines that have been lying around unused for years, it's always good practice to clean ALL of the fuel system.
Pay close attention to the condition of the fuel tank internals as well. Soak the inside of the tank with some caustic soda solution for 24 hours and rinse out with plenty of fresh water and leave to dry. (you might be surprised at how much junk comes out of it!)
Next, have a look at the fuel tap filter.These can often get blocked up with debris leading to fuel starvation problems.A good spray with carb cleaner should sort that.
Give the fuel line a blow through with some compressed air or similar.(carb cleaner works here too)
Re-assmble everything and try again.
Also make sure that the carb itself is tightened securely on its mounting, don't really want any air leaks around the stub fitting.
These seagulls respond well to a really good clean.
All very basic stuff really.

keep us updated with your progress
pics, we like pics

jon

[FoxUk]

Thank you for all your replies...

I believe the problem has been solved. It looks to be a combination of a dirty fuel tank and the carb being loose around the stub fitting. The collar uses a slot screw (old and rusty) which I found I could just tighten it a little more before it started to break up. The engine is now running a lot longer although it still revs up and a down a little on it's own but that might be just because i'm running it in a wheelie bin!

I'm just glad it wasn't compression or something with the block/cylinder as it was in bad condition before I cleaned it up.

I guess what must have been happening was the engine could start ok as it had the right air and fuel mixture but once the engine got warm and running faster under speed, it must have been sucking more air through the loose collar.


At the weekend I will strip the carb and fuel bits for a good clean with carb cleaner and try this caustic soda idea on the tank.

I'm hoping it will become a nice little reliable engine as i'm planning a trip from Oban to the Mull this year which is about 5 miles of sea! and back in my kayak.

Paul

[Charles uk]

That does sound like it's getting insufficient juice into the float bowl, check to see if the needle moves freely, no corrosion around the seat & that a reasonable amount of fuel flows past the needle when the float is dropped.

[Niander101]

Oban to the Mull !...Know it well in fact thinking about moving back up there Tobermory would be nice..
Now then that's an interesting craft you have there!
can see two fuel cans sticking up out of the outrigger.good for exploring eh but do watch out for those very big Calmac ferrys wont you
They will have a Big job seeing you!...It was scary enough in my yacht when they are bearing down on you at speed!

[FoxUk]

Calmac Ferries! HaHa... I thought it was just me. The other year they nearly run me down in the sound of Kerrera so I got myself a VHF radio license (T136325).

The extra fuel tanks are when I get the courage to go for the outer Hebrides or maybe even St. Kilda! one day.

Paul

[headdownarseup]

Hi Paul
yep, the caustic soda works really well on brass fuel tanks. (works ok on steel tanks too provided there's not too much rust inside to begin with)

Give it a go, and i bet you'll be surprised at how much goo comes out of it?
Cleanliness is everything when it comes to a seagulls fuel system. It only takes a few little specs of debris to partially block a fuel line or a jet in the carb and that'll be the start of all your woes.
Try and find a better bolt/screw for the carb flange as any air leak from the base of the carb will throw up no end of trouble for you.
It's all pretty simple stuff on these little motors, sometimes they take a bit more "tweeking" than you first thought to get 'em to run nicely.
Stick with it though as they are fairly strong little things.

jon

[Niander101]

Calmac Ferries! HaHa... I thought it was just me. The other year they nearly run me down in the sound of Kerrera so I got myself a VHF radio license (T136325).

The extra fuel tanks are when I get the courage to go for the outer Hebrides or maybe even St. Kilda! one day.

Paul

You know you are quite mad?...actually there is also a chap down under who has similar crazy ideas of long Ocean crossings!

[headdownarseup]

I shall be meeting up with him quite soon (said mad Tasmanian eccentric sailor person)
Should be a good day out, looking forward to it.

I'll let you know just HOW MAD he really is...!


jon