Simson S51 4Kanal Carburetor

Excill

Hi, I recently made my Simson s51 cylinder 4 kanal and I`m thinking what carburetor I should use ? With the normal carburetor it won`t do full RPM it just doesn`t get enough fuel in.

Fritt3n

Re: Simson S51 4Kanal Carburetor

First of all:
Do you modified the cylinder yourself or do you bought a pre-made one?

Excill

Re: Simson S51 4Kanal Carburetor

I modified it myself , also modified the exhaust and intake and modified the original 2 kanals. I have pictures , I did it by this tutorial http://simson.hu/index.php?mit1…&fokat=4&alkat= .
If it`s unallowed to post links to other forums tell me and I will remove it.
If you want to I can upload the pictures.
PS: What carburetor do they use in the tutorial ? I can`t understand the text but I think it`s from MZ125.

Fritt3n

Re: Simson S51 4Kanal Carburetor

Well, to be honest - I would not trust the hungarian or polish websites at all.
They try a lot of things because they have nothing better than the old cylinders... (take a look in the text yourself, they suggest to use a mixture of diesel with gasoline... thats obivously the worst thing to do on a two stroke)

Building a 4 port cylinder out of a standard 2 port cyl. usually requires a lot of knowledge and experience.
The MZ carburetors are way to big for 50ccm, the standard 16n1-11 is used with most of the high RPM 60ccm 4 port cyl (but it requires a bigger jet !)
Sometimes also the 19mm Version of the 16n1-11 is used.

So if your cyl. does not work right at all, it is more a fault of your work on the cylinder and the exhaust.

May I ask you where you are from?

Excill

Re: Simson S51 4Kanal Carburetor

I am from Bulgaria , everything works well but the problem is that the carburetor can`t get enough petrol in the engine(At top RPM). I guess I`ll try buying the biggest jet and hope for the best. And by the way I couldn`t read anything from that site because google translator is not good at all so I did it by the pictures , but with some things slightly different . I made my 2 extra kanals the way most of the cylinders are done but I kept it at the same level as the original kanals , because the piston won`t go lower than the exhaust if I am right, so it won`t get any extra fuel if the kanals aren`t higher then BDC( Botto dead centre). Also I didn`t modify my crankcase as in the pictures.

der_Ed

Re: Simson S51 4Kanal Carburetor

What Diameter does your inlet have? Thats the size your Carburator should have. Usualy a normal BVF in the correct size should do.

The Problem with not getting enough fuel at higher RPM, I think is a case of the air inlet filter. Did you modify your air filter?
There are several manuels how to do that. Mostr important ist to replace the original filter by something that allows more air to pass. Then you need to get a bigger jet diamiter.
What diameter your jet needs to be tells you the spark plug, it needs to be brown, black means jet to big, white means jet to small. A to small jet can damage the Cylinder by to hot combustion.

Excill

Re: Simson S51 4Kanal Carburetor

I haven`t modified my air filter and before I made the changes the spark plug had a perfect colour (brown). I haven`t driven it a lot after the modification on the cylinder so I cannot tell. I am not near my bike all week ( just 2 days ) weekdays I`m in another place so I cannot try making changes now. I`ll buy a bigger jet it`s not expensive and a new air filter (or maybe modify mine if i find tutorial).
And about the colours of the spark plug I know how it should be and how to read by the plug and set up the carburetor. I talked to a guy from my country which made his cylinder 60 cc + 4 kanal and uses 21 mm Dellorto carburetor. That`s why I asked about the carb.

Fritt3n

Re: Simson S51 4Kanal Carburetor

The color of the spark plug is just a rough help for orientation so don't let yourself fool by it.

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