Como .50
07-20-2012, 01:37 PM
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Como .50
I have an old CoMo .50 that I have never run in the several years that I have owned it but I want to get it running now. My question is for all you old CoMo and Super Tigre fans: where do I start with the needle valves? I assume the one on the exhaust side that looks like an actual needle valve is a low speed valve and the one on the intake side is the actual high speed valve. From lightly seated, where would I start with these valves to get it running?
07-20-2012, 03:27 PM
#2
RE: Como .50
Here's the old Super Tigre low speed needle method. It does take 3 hands or some help unless you have the throttle hooked up.
1. Hook a 8-10" long piece of fuel tubing up to the carb nipple
2. Screw the low speed needle closed.
3. Put a T-pin in the carb throat and pull the carb closed. This leaves a very small gap, approximately idle size.
4. While holding the carb lever to keep the T-pin captured. blow into the fuel tubing and slowly open the low end needle.
5. Put your ear down near the carb and when you hear the first hiss of air, stop opening the carb low end needle
That's it, low end set.
As for the high end, open that needle 3 turns and crank. Leave the glow ignitor attached and rev to full power and slowly lean out the mixture. Leaving the battery attached to the plug insures that if 3 turns is too much, the engine won't quit rich.
Once you get the top end set, go back and check the low end.
Your engine more than likely has old oil congealed on the inside of the carb, reducing the clearances. As you run it more, this will wash away and you'll need to lean out both hi & lo ends somewhat.
1. Hook a 8-10" long piece of fuel tubing up to the carb nipple
2. Screw the low speed needle closed.
3. Put a T-pin in the carb throat and pull the carb closed. This leaves a very small gap, approximately idle size.
4. While holding the carb lever to keep the T-pin captured. blow into the fuel tubing and slowly open the low end needle.
5. Put your ear down near the carb and when you hear the first hiss of air, stop opening the carb low end needle
That's it, low end set.
As for the high end, open that needle 3 turns and crank. Leave the glow ignitor attached and rev to full power and slowly lean out the mixture. Leaving the battery attached to the plug insures that if 3 turns is too much, the engine won't quit rich.
Once you get the top end set, go back and check the low end.
Your engine more than likely has old oil congealed on the inside of the carb, reducing the clearances. As you run it more, this will wash away and you'll need to lean out both hi & lo ends somewhat.
07-20-2012, 03:31 PM
#3
RE: Como .50
Here's the old Super Tigre low speed needle method. It does take 3 hands or some help unless you have the throttle hooked up.
1. Hook a 8-10" long piece of fuel tubing up to the carb nipple
2. Screw the low speed needle closed.
3. Put a T-pin in the carb throat and pull the carb closed. This leaves a very small gap, approximately idle size.
4. While holding the carb lever to keep the T-pin captured. blow into the fuel tubing and slowly open the low end needle.
5. Put your ear down near the carb and when you hear the first hiss of air, stop opening the carb low end needle
That's it, low end set.
As for the high end, open that needle 3 turns and crank. Leave the glow ignitor attached and rev to full power and slowly lean out the mixture. Leaving the battery attached to the plug insures that if 3 turns is too much, the engine won't quit rich.
Once you get the top end set, go back and check the low end.
Your engine more than likely has old oil congealed on the inside of the carb, reducing the clearances. As you run it more, this will wash away and you'll need to lean out both hi & lo ends somewhat.
1. Hook a 8-10" long piece of fuel tubing up to the carb nipple
2. Screw the low speed needle closed.
3. Put a T-pin in the carb throat and pull the carb closed. This leaves a very small gap, approximately idle size.
4. While holding the carb lever to keep the T-pin captured. blow into the fuel tubing and slowly open the low end needle.
5. Put your ear down near the carb and when you hear the first hiss of air, stop opening the carb low end needle
That's it, low end set.
As for the high end, open that needle 3 turns and crank. Leave the glow ignitor attached and rev to full power and slowly lean out the mixture. Leaving the battery attached to the plug insures that if 3 turns is too much, the engine won't quit rich.
Once you get the top end set, go back and check the low end.
Your engine more than likely has old oil congealed on the inside of the carb, reducing the clearances. As you run it more, this will wash away and you'll need to lean out both hi & lo ends somewhat.
07-24-2012, 10:14 AM
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RE: Como .50
Another way as stated on the supertiger carb instuctions is to remove the carb and screw the idle needle in until the needle is halfway across the catseye opening and to make sure the catseye is pointed straigh down the barrell. That is the starting point. After you get it tuned, you can turn the catseye slightly to the side either way for good midrange. That is how I did my como 90.
07-24-2012, 11:46 AM
#6
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RE: Como .50
Como engines (made by ST) have not been around for a very long time. Your description of what the high and low needle valves look like (not where they are located) seems reversed from what I remember. ST had a carb of the week in those days. Ed's technique is an old but excellent start.
Paul
Paul
