Idles only on choke and try’s to runaway when reving, it has ran-away once.

Discussion in 'Carburetor' started by Logan190, May 19, 2021.

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Why does my blaster not want to idle without choke

  1. Carburetor issues

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  1. Logan190

    Logan190 New Member

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    So I’m tying to fix a blaster that has been sitting for 3 years. All I have done was regular maintenance and replaced the reed valves. When I try to start it it is not getting enough fuel I think. Because I have to use starter fluid to get it going when it’s cold. For it to idle I have to have the choke at least barely sticking out. For it to run good, but because it idles when choke is on it gives way more fuel and it Revs really high when I press the throttle. I was trying to tune the idle speed and air fuel mixture while it was running with the choke of so I had to keep the throttle going a little. Then the engine just went wide open and stuck there. And the kill switch did nothing So I plugged the carb and it stoped. I don’t know what is wrong with it I hope you guys can give me a start on where to look at and fix.
     
  2. JLG

    JLG Member

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    Sounds like the pilot jet is plugged. Have you cleaned the carb? If you clean the carb and everything checks out good, and it still revs high in its own, then you could have an air leak.
     
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  3. Slydog

    Slydog Active Member Technician

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    You should do a 2t leakdown test to check for airleaks. Air leaks can cause the motor to run away. Can't really tune it if you do have a leak.
    Is the carb squeaky clean? Slide or throttle cable hanging up?
     
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  4. Logan190

    Logan190 New Member

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    Yes I’m going to take apart the jets toda. I cleaned the carb but didn’t have time to get all the jets cleaned, I will get the pilot jet cleaned up and the rest of the jets
     
  5. Logan190

    Logan190 New Member

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    I will try an air leak test, thanks for responding. I will also investigate the carb.
     
  6. Larry's Shee

    Larry's Shee Active Member

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    Start all over again cleaning the carb. Remove both jets and the main jet holder/emulsion tube, and air screw, choke. Make sure you can blow air through ALL passages. Make sure you can see through the Jets and holes on side of emulsion tube.. Set float.
    List ALL your mods , jet sizes, air screw setting. How does your plug look.
    Odds are you have an air leak from installing the reeds. Care must be taken to torque them incrementally in a crisscross pattern.

    Best way to kill a runaway is shift into second gear, hold brakes, dump the clutch.
     
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  7. Logan190

    Logan190 New Member

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    Thanks for replying! Ok I will tear apart the carb tonight and make sure the reads are the correct spec. I have stock everything expect for air filter and replaced the stock reed valves. And stock 1 and a half turns out on air fuel mixture screw. My plug had a little bit of black on it before the runaway happened.
     
  8. Logan190

    Logan190 New Member

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    I have cleaned out the carb completely. Took apart and cleaned the main jet, pilot screw.main nozzle. Then I started it and it didn’t runaway or have an issue with that at all. But it still will only idle with the choke on. Every jet I took off, I could see through the hole after cleaning it. I am thinking it is a leak somewhere so I will do a leak down test. Because I think it’s not getting enough suction from a leak. The spark plug is a little black so it’s getting to much oil. Do you think that could be the issue?
     
  9. Larry's Shee

    Larry's Shee Active Member

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    1 1/2 turns is ONLY a starting point. Every engine is different !! What does yours want ?? Try turning the throttle stop up a little bit. Also try adjusting the air screw. Turn it one way or the other, blip throttle couple times and let it settle down. If not better, try it opposite way. This is known as “tuning”
    Oil injected or pre-mix? What oil and/or what ratio?
    Do you have stock air filter and/or lid and snorkel ?
     
  10. Slydog

    Slydog Active Member Technician

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    Did you blow compressed air thru all passages like mentioned. Jet maybe clean but passages may be plugged. Aur filter clean?
    Are you premixing at 32:1. Or using the factory oil injection?
     
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  11. Logan190

    Logan190 New Member

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    I got a new carb and hoping it will work. I just can’t get to working on the blaster rn cause I’m so busy. I just did an oil delete last week and i have a brand new aftermarket air filter with oil in it.
     
  12. Larry's Shee

    Larry's Shee Active Member

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    If you look around you’ll see that China carbs are your problem. Wrong Jets, float level, slide, and just sh*tt design/quality
     
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  13. Logan190

    Logan190 New Member

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    Yeah if the new carb won’t work I’ll get a rebuild kit and a new throttle cable that doesn’t have the tors system deal on it.
     
  14. Slydog

    Slydog Active Member Technician

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    If the new carb was $30 it won't work like was mentioned. Those carbs are designed for a smaller engine.it will run super lean and fry your top end. Or won't run at all. Every internal part of those carbs are. Wrong
     
  15. Logan190

    Logan190 New Member

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    Well this was totally unexpected, but the 4 wheeler is running and idling perfect with the Chinese carb on it. I didn’t even change the jets in it. It will likely be my temporary carb until I get a rebuild kit. The only issue now is that it’s burning a lot of oil.
     
  16. Slydog

    Slydog Active Member Technician

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    Start saving for a top end rebuild if you are using that carb.
    The Jets and all other parts are wrong, and setup way leaner than will work on any blaster.
     

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