Hipolito 250 repair

I recently found a Hipolito 250 and tried to check and repair. Dipping the pressurized lantern in water, it revealed a small leak just above the central nut of the carburattor as the red arrow shows in the image attached. Is there any sealing rubber in there? In any case, I tried to remove the upper part of the carburattor by unscrewing the nut (1). But trying to lift up (2) it moves, say, 1 or 2 centimeters and then it gets stuck. Before I force it out I though of asking here if there is anything special with hipolito I should know.

The needle works and moved up and down before I unscrew (1), but there is a scratching sound when it moves. So it is either dirt, or maybe something installed in the carburattor (like brass mesh? who knows...) or hipolitos have something special I do not know.

So I wonder how to remove mast (2) ? Force it out? spray WD40 from the top after removing the nozzle first? What do you think is safe here?

And why there is a leak at this point; I do not remember my Petromax to have any rubber there. Does hopolito have anything there?

 

@Antonis Tsolomitis , There is no seal between the vapouriser and the control cock. It relies on a brass to brass seal. Clean the mating surfaces and check for any scratches or other damage.

The vapouriser should lift off, but it probably has a build up of carbon on the shaft below the cleaning needle. Remove the jet and cleaning needle so they don't get damaged and apply a moderate amount of force to remove the vapouriser.
If that doesn't work unscrew the pricker operating mechanism and the vapouriser unit will separate from the cock. It can then be heated to burn out the carbon.

This might help Hipolito 250 Fettle and Manometer Question

 

Short answer: no there is no rubber there.

Long version: after releasing the nut, the vaporiser should come off.
If not, remove the needle, if not then there is a blockage in the vaporiser tube. Remove that or buy a new vaporiser.
Which may be difficult because 250cp versions where not made a lot.
On the other hand: any petromax clone should fit.
The needle rod is screwed into the extender block which is operated by the hand wheel. So normally this rod stays on the valve when removing the vaporiser.

 

Thanks for the tips and information. I will try to remove the needle and see if it comes off. Also the unscrewing of the rod from its base is a good idea. I will try (later) and get back.

 

I removed the needle. The vaporizer could not be removed so I lifted it a bit to expose the rod and unscrew the rod from its base. With a few strokes back and forward of the rod in the vaporizer I removed it and a lot of "sand" fall off. I can easily clean the rod but how to clean the vaporizer inside with its Preston loop. Should I use some kind of solution to dip it in or use another method? A torch? The vaporizer and the rod are not straight. Check the pictures below. But the needle was working fine before I dissasembled it. Should I leave it as is? I may straighten the rod but I do not think I can straighten the vaporizer...





Another question is about the pump. I have repaired the valve in the pump tube and I can add pressure with a Petromax pump (piston and leather). But its own pump-piston does not seem to manage to push air in the tank although I feel the resistance in both directions. This is different than Petromax. Here are two pictures of it:




I have not seen such a construction before and never seen such parts online for sale. If this is correct then I need to switch to Petromax parts. Right?

 

The pump is mounted incorrectly. In some lanterns, the leather is not firmly attached to the pump rod, but is mounted on a fitting that can move up and down a little at the end of the pump rod. This makes the work easier when the leather is pressed very firmly against the walls of the pump tube, because no negative pressure builds up when the rod is pulled.
However, the round brass part with the slot should point towards the end of the pump rod and is normally surrounded by the leather cup. The octagon nut should press the leather onto the brass part. Your leather seems pretty worn, so a new one might help get it going again. But you could also try reassembling everything properly and see if it works.

 

Indeed yes, the components are on the shaft the wrong way round HERE’s an illustrated account of the working of such a pump.

Applying a blowtorch to the seized nut will free it.

 

Looking at the vaporiser and needle rod I think the best option is to buy new ones. Together with needle and jet.

 

Sure I could by new ones. But where from... Is there any source? petromax.de does not have them. If you know any source please advise me.

About pump, thank you. It is very strange it is reversed. this is how I bought it...

 

It seems difficult to get a replacement. I looked at ebay and also searched with Google, no results. I will keep searching, but in the meantime I have the parts of the lamp as I bought it. So what is a way to clean the vaporizer internally? Is it completely hopeless?

 

You can clean the vaporiser, so you don't need to buy a new one. The straight part can be drilled out, and for the loop you can try to use a bicycle Bowden cable inserted from the top. But please take care for the jet's thread and seat.
The procedure will be more satisfactorily when you heat up the vaporiser in advance, in order to burn out any volatile fuel residues that may have gummed up it inside, and leaving the pure carbon.

 

I have chinese versions of these lanterns with very bent vapourisers and rods. As long as it can move the needle in and out of the jet it is working ! You can straighten them out but go carefully.

 

What does "The straight part can be drilled out" really mean? Drill means open a hole, but here it surely means something else. What is a tool for this? For the Preston loop I will try to find a Bowden cable. Thanks for the idea. But no chemical solution exists (which would be easier)?

There are some products called "Carbon off" or carbon removers for carburators. Even oven cleaning spray is supposed to take off carbon. There is no hope with those? I ask because a chemical solution is simpler and will not damage (I assume...) threads etc. One would think to immerse the carburator in a soda solution or oven cleaner liquid. But maybe this is not safe for brass?

 

I am afraid to straighten the vaporizer. I really do not know how to do it. The rod moves inside it OK. So I just need to clean things up and test. Until I find a "new" vaporizer and rod to buy.

 

Just use a metal drill of suiting diameter (don't know the exact diameter, could be a 6.5 mm) and insert it from the bottom. This will scratch the carbon out from the raising tube. Stop drilling at the level where the loop is soldered in, because there is a smaller diameter which only fits the needle rod. Of course a prerequisite is that the vaporizer is not bent.
The vaporizer can easily be straightened by hand. To check the result simply twist it between two fingers and observe how the bending changes.
I'm still not much convinced by chemical solutions, but there are other forum members who had good results with carburetor cleaning agents.

 

Pre-soaking the generator in a concentrated lye solution might help loosen a lot of semi-carbonized old fuel. It should complement mechanical cleaning and make things easier.
However, in many situations, what you'd find inside the Preston loop generator won't be just semi-carbonized fuel alone. Instead, you might find hard-coked fuel residues, which is a mixture of pure carbon and some other non-soluble impurities.
There aren't many chemicals that would react with hard carbon. It is not chemically reactive when cold.
Any chemical that would react with hard carbon won't be friendly to most other things as well..
A possible example would be some mixtures of concentrated sulphuric acid(~98%) and strong(>30%) hydrogen peroxide. They are normally called 'Piranha Solutions'. Used for removing those 'hard-to-clean', tightly adherent carbon or soot on laboratory glassware (borosilicate/pyrex). The solution has been known to oxidize pure carbon deposits. (The removal of hard carbon deposits requires highly oxidizing conditions).

Alternatively, we sometimes perform the heat-and-quench on the generator to loosen those hard coke within.
The carbon within the loop can also be burned off if you have a special assembly to inject air or oxygen into the generator with the jet removed. The generator would be heated to dull red hot while air or oxygen being fed-in from one end. There'd be an eruption of sparks from the burning carbon in such procedures. This would last until all the carbon has been oxidized or burnt. Great care required for this so that heat is well-controlled,.. as to prevent the generator from melting.
The generator can be straightened if required. After a number of heat and quench cycles, the brass on the generator would be soft enough that you can easily bend it back as straight as your eye can tell.

 

So chemical solutions are not easy either (sulphuric acid is not a "friendly" chemical). So my best bet it to start with mechanical solutions and see how it goes with a Bowden cable.

If the vaporizer can be straighten by hand then a (non-rotating) drill will help to guide the "straightness". Thanks for all the tips and information. I will see what I will manage to do.

 

OK, so I removed the nozzle, the needle, the vaporizer and cleaned up everything to the best I could with mechanical means. The Bowden cable worked well with the Preston loop. I put everything back together, the needle passes OK through the nozzle. I pressurized the tank and I hear a small hiss and can feel the air escaping through the needle hole although the needle is up.

This means that the foot valve inside the tank needs replacement. Before I remove the lower part of the generator does anyone know if the foot valve is the same with Petromax? Because the pump's valve was different and I needed a special key to remove it an replace the hardened rubber in there. If it is not similar maybe I can leave it as is... and start pressurizing when the second filling with alcohol is being burning... If it is similar I will go ahead to order the Petromax part to replace.

By the way will the Petromax leather cup for the pump will work with this pump piston? It has a different ending than Pmax.

 

This Hipolito does not have a carburettor foot valve.
A Petromax pump leather fitts ,but you have to enlarge the inner hole.

 

If it does not have a foot valve what does it have? Can I fix this leak or not?

 

There is usually a piece of brass gauze installed at the end of the suction pipe in the tank to prevent dirt from being sucked in . That's all.
Pressure lamps without rapid preheaters don't really need a foot valve.

 

This can not be entirely true as I own a Petromax 500 without a rapid preheater which does have a foot valve which I replaced. But you say that there are lamps like Hipolito that do not have this. So the leaking hiss from the nozzle with the needle up you say that it is normal. OK, then, even better, I do not have to mess with the lower carburetor part! Thanks!

 

Even a Petromax without a rapid preheater doesn't really need a foot valve.
It was only used to prevent fuel from escaping from the jet when there is fuel in the tank in the event of temperature fluctions.

 

Maybe it it better to conclude that this is not a leak. Like Reinhard says: there is no valve. This also means you don't pump before the vaporiser is heated up.
Pre heat > close air release screw > pump > enjoy.

It also means you have to study the design so you know how and why it works.
This is essential when solving problems and in regards to safety.

 

Sure, yes, I am doing this as you describe. I have to do the dip in bucket test to make sure I have no leaks from other points and then I will try to light up the lamp. I will report back if I succeed or if I have problems.

 

Good! No visible leaks with water covering up to above the Preston loop. Last thing before I assemble everything back. Is it a good idea to pure in the tank some white benzine (the one used to clean cloths), swirl it a little and empty it, in an attempt to have some minimal cleaning of the tank internal walls? Of course I will empty it and let it completely dry before I attempt to fill with kerosene and light it up.

Or better do nothing?

 

Bad luck. I tried to assemble the lantern and barely touched the burner to check that it is secured. Half of it fall in my hand. Now I have to wait for a burner to come after I locate one. The Petromax shop on the HK250 pages lists the clay burner as HK150. I wrote to them to correct the mistake and see if the 250 version is available. Waiting...

By the way, what is the difference of the clay burner and the oxide burner? The oxide burner is double the price on Ebay than on Petromax shop (although sold out for the moment).

 

I would order at base camp.
Any 250cp parts will fit. Old parts are the best.
If the clay head is cracked in two piece that match well, you may simple put it together again. Worked on one lantern perfect for me.
Due to the heat/cooling cycle these burner tend to get loose. Mount the new one with a piece of mantle thread (the parts you cut off) or put a little exhaust kit on the thread.

 

Unfortunately, although they natch well, the crack is horizontal, parallel to the threads between the threads and the head of the burner. I do not see how to tie this. But I do not know what is the "exhaust kit" you mentioned. Is this a product that you could show a link so that I understand what it is?

Yes it seems that base-camp is the solution although I will look first inside EU because customs here are very very slow.

 

Oh dear - yes the 150 and 250 are I think different sizes.
The clay burner is the original material. The oxide ceramic ( I think the same as alumna silicon oxide) version is made of a more modern material - the same stuff that Mig and Tig welders use on the gas nozzle. It should be more robust but I cannot speak from experience as I have never had one. You also see stainless steel ones but these have had mixed reponses on this site.