Saving Old Seagulls

I run my two silver century with the old cooper gasket and signs of bad sealing, drops of water coming out of the point of the copper gasket etc.. The exhaust was creating too much smoke.

Then I used permanite and RTV in the cylinder head. There was no smoke at all. I know that good sealing of the block leads to perfect combustion. And when more than the appropriate air gets in the combustion chamber creates semi combustion and smoke out of the exhaust.

So am I right about that? Does good sealing on cylinder head leads to less/no smoke?

Youll never get no smoke as it the oil thats burning
we like smoke anyway dont you?

I like it in gentle amounts..! In addition I prefer perfect combustion.

Smoke is a rather vague term and a little hard to nail down where Seagulls are concerned. There are a lot of variables, oil types, mix ratios, atmospheric conditions etc. etc. What would make a lot of "smoke" would be if the poor gasket seal was allowing some water into the cylinder, it only requires the tiniest amount of water to create a very impressive steam cloud on an internal combustion engine. I had a minute hairline crack in a cylinder head on a car once and even though I was losing relatively little water the vapor trail had to be seen to be believed.

Usually any type of problem that causes a 2 stroke to run other than at the optimum, is accompanied by additional smoke other than perhaps overheating, or lack of oil, but even those problems usually end in a cloud of smoke when something starts to let go.

In my occasion the difference was amazing. Both times I used 1:10 oil to petrol and the same 2 stroke oil (quicksilver tcw3). Water must have been a reason as I was watching drops coming out of the gasket.

If water was leaking out of the gasket there's a good chance some was going sideways in to the cylinder, so if you had a huge amount of smoke that disappeared after sealing the head gasket that sounds like that was your problem. The suction caused as the piston draws mixture into the cylinder can also pull water through the tiniest of openings and it takes almost nothing to create quite a "smokescreen"

I forgot you were in Athens, Greece, you don't get that miserable cold British overcast weather that can make a plume of 2 stroke smoke hang in the air so effectively Here in UT with the hot sun and dry air you just don't seem to notice it the same as I did in my youth in boating in Wales in their typical "summer" weather.

Can you explain "the suction as the piston draws mixture into the cylinder"

[quote="fortyplus"]

I forgot you were in Athens, Greece, you don't get that miserable cold British overcast weather that can make a plume of 2 stroke smoke hang in the air so effectively

Hey we get loads of hot sunny days here also ya know

but ya know whats best about being in the uk?

Seagulls !

there everywhere man they are falling out of sheds all over the country just waiting to be picked up for pennies!

Did you know the Seagull is the State bird of Utah? as a result they are protected here and you cannot shoot them.

I think I am however the only Seagull motor owner in UT, there used to be two of us, but then I bought his Seagull 90. My one 76 40+ came out of Texas, I paid $25 for it. Now I've finally, after 3 years, got round to cleaning it up a little, I'm realising that it's a much nicer motor than I ever thought. I think it was barely ever used, but then was left in a storage unit where water got onto the top of the tank rusting it and getting on to the one side of the drive tube causing some pitting. A lot of the other stuff I thought was corrosion turned out to be old dried oil and came off with lacquer thinner. I've painted the flywheel, gearbox and am still working on the tank, but now realise this will be every bit as nice as my one owner, low hours 40+. Only the prop lets it down, it's very clean and has all the original paint, it just looks like the one time they used it they were tilling the garden with it rather than boating - it's a little bent and the corners are a little rounded on a couple of the blades. It still works but now the rest of it looks so nice I must upgrade.

I know you get sunny days in Britain, I lived there for 40 years - they just didn't seem to coincide too often with when I needed them

Can you explain "the suction as the piston draws mixture into the cylinder"

I was waiting for that

B

Charles uk wrote:Can you explain "the suction as the piston draws mixture into the cylinder"

I guess as there is only a firing stroke on a 2 stroke no suction is created in the cylinder during normal running as there is on a 4 stroke, other than when trying to start it when there is no ignition of the fuel mixture or when running to a stop with the throttle closed. So if there was water entering the cylinder it was most likely getting in immediately after stopping the motor while it was coming to a stop without ignition of the fuel mixture.

I always thought, that the piston going down increased the crank pressure to load fuel into the cylinder though the ports and the upward stoke pulled more fuel into the crank case from carb.

Sorry about that, I edited my post while you were posting. I think while the motor is running there will always be a positive pressure in the cylinder because it is always on a firing stroke, when you cut the throttle and it runs to a stop you will get a negative pressure in the cylinder particularly before the ports are uncovered and possibly afterwards depending on the relative volumes of the cylinder and crankcase. Does the cylinder casting allow for water to get drawn in through the transfer ports - do these channels run to the top of the casting and the head gasket?

The downword motion pushes the fuel/air mixture out of the crank through port at the bottom of the cylinder, seals it and sucks it out the top port into the cylinder.
Once the piston reaches the bottom and starts going back up it sucks fresh mixture into the crank case whilst compressing the mixture in the cylinder prior to ignition...

Atleast thats what I think happens

Neal

Something like that.