Two speeder engine work: several questions

[Deleted User]

Hello all,

Today I started the engine work on my two speeder. I have several small jobs to tackle to get the bike in perfect order for this season:

– give the engine a decoke
– reseal the waterdome (and now for good)
– check the overall condition of the engine
– etc.

According to several Scott publications it should be possible to lift the engine out of the frame without disassembling it first.

But no matter how I try, the engine will not come out. Main obstruction is the exhauststub on the block. It will not clear the frame. Does the frame or engine of my Squirrel differ from that of a Super Squirrel?

Second question… When I disassembled the exhaust a considerable amount of water gushed out. Not just a few drops… It was water from the radiator judging the smell and color. The radiator has been dry for quite some time now. How could the water get there? There was no water in the crankcases, just oil in the wells. During the last season I never noticed a leak. I did at one time unscrew the LH ferrule when trying to check the plug. But after fastening that again I regularly checked the LH crankcase for water and never found a single drop. And today I could even unscrew the plug again without loosening the ferrule again. Any ideas on this? I do not have the engine open yet so I might find something there.

But first I have to get it out of the frame…

Cheers,
Erik

[lewis onions]

Hello Eric – I had the same problem when I tried to take my 2 speeder’s engine out. After much head-scratching I discovered that the exhaust stub is removeable. It should be possible to tap it out. Hope this helps.

Can’t help with the water though!

[Deleted User]

The only way to test this with any degree of certainty.
Fit the water dome. I just fit them with silicone sealer. no more problems.
Blank off one hose
Pressurise the other if you can to about 20psi
Immerse in a bucket of water
Watch for the bubbles
My guess is a leak from the water jacket into the exhaust chamber
Because it is inclined forward, it will run into the exhaust rather than back into the crankcase.
If you can locate the position, you might be able to block it up with some thin epoxy
Best to clean and dry block,
Put some small stones or ball bearings in the water jacket
Shake it to try and clean soft calcium residues
Put some cleaning solvent in
Pressurise to blow it through the leakage cracks
Empty and dry
Put in some thin epoxy and incline to get it to run to area where the crack is. Slow set is best if you can get it, as you can put the top on and pressurise the sealant to try and get it to go into the cracks.;
Pray
If you could get thin silicone sealant, this might be good, as Hertel have stopped making “Slow set Plastic Padding” in Finland and I have not found an alternative yet.
No use getting worried too quickly, but the pressure test, similar to finding a puncture in a tyre is the best test.
If you do not have a compressor, cut up an old bicycle inner tube.
Fix one end to one of the water pipes. Block off the other water pipe.
Block off the open end of the cut inner tube
Blow up the inner tube and the elasticity of the tube will exert the air test pressure you require.
Let us know what you find
Kind Regards
Roger Moss

[Deleted User]

Thanks guys for the tips! But looking at the exhaust stub I wonder if it will tap out that easy…

Will keep you posted on the progress!

Cheers,
Erik

[Deleted User]

Well, this evening I finally tried the method Roger suggested for testing the block for internal leaks. I bought myself a brand new bycicle inner tube (must be the only Dutch guy without a bike and thus had nothing lying around…). It took me quite some time to get it attached to the block without too much leaks. Finally it was kind of watertight and in it went….

With no results at all! I know the block has a few leaks. Everytime the bike stood for a while there was quite some water around the RH ferrule and there was also a small leak on LH side at the rear. Enough to wrap a towel around the block everytime. And the amount of water I poured out of the exhaust was enough to keep a couple of goldfish in… But not one single air bubble at all, not even after an hour! I could not measure the pressure in the tyre as my pressure gauge did not fit a bicycle tyre but given the proportions of the inflated tyre it must have been quite enough…

So how did the water get in my exhaust?? Or do I really have to apply even more pressure?

I am quite puzzled…..

Another thing I found was that the LH bigend kind of dropped out of the conrod spontaniously. But that is another story…

Cheers,
Erik

[Deleted User]

Sorry Erik but it’s just that brush hanging on the wall, I keep getting this picture of you sitting in that box getting your back scrubbed!

On a more sober note and notwithstanding the comment about the colour and smell of the water found in the exhaust, could it not be a combustion product? Maybe the hint lies in the name, Hydrocarbon, burn a gallon of petrol (4.45 litres) and among the other products of combustion you get about 10 pints (5.7litres) of water.

Referring to the pressure test, very ingenious but I doubt that you got more than a couple or three pounds of pressure in that unsupported inner tube. More pressure might reveal something but probably not and after all it is not a pressurised system.

[Deleted User]

Hello,

For the purpose of leak testing both the block and the radiator what psi would be recommended?

Thank you

Blaine

[Deleted User]

Probably 10 psi would be plenty enough particularly in the case of an old radiator.

To get that pressure all you really need is a 30ft. length of vertical hose or pipe and some way to keep it vertical, a house, a handy tree or even a flagpole would do! If a ”Tee” was introduced into the hose then the head and therefore the pressure could be adjusted via the domestic supply. Atmospheric pressure will support a water column of about 40ft (12.2 metres) so 30ft should give about 10 psi.

[Deleted User]

I intend to try another method. Blocking off one hose and fit a plug with a normal valve (one that I can measure) in the other end. That way at least I will know the pressure inside. And will be able to get more air in.

But, regardles the pressure, when the bike just stands it leaks water at several places. With the radiatorhoses not being 30 ft long ;o) there is no actual pressure. So why would the water leak out but not the compressed air? As far as I know air is not thicker than water…

And of course it could be water from the combustion but the smell, colour and freshness (it was almost as clear as tapwater, just like in my rad) would indicate it being radiator water.

And the brush? Well that is used to clean the cats litter box rather than my back ;o)

[Deleted User]

On the matter of water leaks, you are quite right about water, it isn’t thicker than air, just more devious . . .

I would have expected the water component of the combustion process to be clear although somewhat acidic, particularly if allowed to stand for some time so that any insoluble particulates might settle, after all Hydrogen + Oxygen = water. The only way to be sure would be to put some sort of colourant in the cooling water, fluorescein being the substance that comes to mind.

I know that on the face of it 40ft of pipe sounds like a daft idea but as a method of obtaining some pressure it has the merit of simplicity. All you need is a garden hose or some domestic copper pipe and somewhere to hang it, no pumps or compressors needed.
Every 2.7ft of head gives you 1psi so a 27ft head will give 10psi and that’s little more than the gutter height of the average house. Vary the height by a known amount and you know the pressure, even a Meerkat could do it!

And finally, notwithstanding that feeble excuse about the cat’s tray I still have this image of a bloke wearing nothing but a silly grin and some soap bubbles – but then I either need therapy or will soon or as my Grandma was wont to say, “The whole world’s queer save thee and me and thee’s a bit peculiar!”

[Deleted User]

Erik, I suspect the ferrules as being the area where water is leaking, entering the cylinder and seeping down the cylinder wall and out the exhaust. I ended up making new ferrules, specifically to suit my engine, to cure a very similar problem. If one of your ferrules unscrewed when a plug was removed, it was not really fitted properly.

Interesting that Roger recommends using silicone to seal the water dome. I finished up using cork gaskets as the most successful, the cork being about twice as thick as the club supplied ones. The cork was purchased from an Auto Supply store.

[Deleted User]

Update on the pressure testing…

Because the bicycle tyre did not show any bubbles at all I made a different set up. Blocked off one hose and made a stop for the other hose in which I incorporated the valve from the bicycle tube. And in the water it went again. Now only one or two pumps of air were sufficient to show bubbles in three separate places! At the LH and RH rear (both known leaks) but no leak at the RH side ferrule (were the water was when the bike stood for a while), no matter how much air I put into it. But also no leak in the exhaustport etc. So this test at least worked.

It also showed a new leak between the two cylinders at the front (behind the waterpipe). A closer look revealed that the block was cracked over both cylinders and soldered up. And this leaked…. So I soldered it up again (or twice to be precise as it was very difficult to get the solder to stick on the 80 year old cast iron). Hopefully it is watertight now.

The LH ferrule that came loose earlier when unscrewing the plus was now so tight that I could not remove it, even with considerable force. So I left it in place.

To fill the gap between the waterdome and the barrels I turned two aluminium rings of the right size. I installed those with silicone gasket thus also sealing all leaks that might still be there around the ferrules.
This rings also enabled me to fully tighten the ferrule nuts without the chance of distorting the waterdome. I only hope I have calculated/measured the thickness of the rings to be the right size. I measured the gap between the waterdome and the barrels and compared this to the cork gaskets I am using (the thick, 1,9 mm version) and turned the rings somewhat smaller in order to be able to compress the gaskets a bit on installation.

I hope to do another pressure test before installing the engine back in the frame. So to be continued…

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