Home Forums 2-Cycle Racing Older Sonik engine question

This topic contains 4 replies, has 3 voices, and was last updated by  Otto Hoel 4 years ago.

  • Author
  • #48337

    Otto Hoel

    I have on older Sonik engine that I would like to identify.  I’ve been looking for a serial number or model designation, but cannot find any.  Is it hidden somewhere?  Do I need to remove parts to find it?  The real reason for asking is that I need to overhaul/rebuild the carburetor and I have no idea what type/model it is, so I can’t order any parts for it.  I figure if I knew which model engine I have, I could figure out which carburetor is bolted to it.

  • #48349

    Walt Gifford

    Engines don’t have serial numbers (except rotax) and the carb is usually made by someone else anyway. If you could post a picture… it’s probably a Tillotson HL kit you’re after. Look on the mounting flange of the carb for numbers.


    FAA certified jet engine and aircraft technician,
    Nicholson Speedway class champion 2001,
    Yamaha KT100 Service Center,
    41 years karting experience

  • #48433

    Otto Hoel

    Hi again,

    This is more of an FYI for others looking for this info.

    Finally got somewhere.  Following Walt’s advice above, I had to remove the carb to see anything at all, and once I got the grime off I could see that it was a Tryton.

    Typing this name into Google eventually got me to TSracing and their parts catalog, where I learned that there are two different versions of this engine.  A 125cc and a 118cc.  The first one has a TX designation and the smaller one is called a VX.  They have different gaskets for the reed-valve to block and the reed-valve to carb connections.

    Here is how to tell what you got:

    Look on the front of the engine, lower side near where the engine mount is, and you should find a number.  If that number is above 1000 it’s a TX125.  If the number is below 1000 it’s a VX118.

    You can also look at the top of the crank case near the reed valve opening there may be a letter “T” stamped in the case.  This means you got a TX125.

    I found the T and it looks like this:

    (Well, it would look like this if I could get the picture posted.  But I can’t, so you’ll just have to imagine.)


    Hope this helps somebody else looking for this.


  • #48576

    Taylor Young

    The carb is a Tryton M1. Many other older engines used the same carb so parts are still available. I think Italian Motors has them.

    There’s also 2 versions of the TX, the older TX have an 18mm crank pin and the newer ones have a 20mm crank pin. I ran them a lot a number of years ago. I have a whole carb for sale too right now in the classifieds.

  • #48796

    Otto Hoel

    Hi Taylor, and thanks for the info.  I’m not aware of which of the crank pins I have, but I’ll probably have TSRacing take a look at the whole kart eventually.

    I finally got the parts and the carb rebuilt.  Took me a while to figure out how to set the needle arm so that it could not leak fuel all over my floor.  However, it still will not start.  I got a spark, but no fuel.  I got a slight fuel drip out of the front of the carb after cranking, but nothing gets into the cylinder, the spark plug is dry.  So more research ahead.

    Thanks again for your info, it all adds to my knowledge.


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