KymcoForum.com
General => General Discussion => Topic started by: dreflu on February 17, 2011, 07:29:36 PM
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I picked up a 50cc cobra from a friend of mine. Its getting fire and gas but wont start. ive tried choking it by hand starting fluid in the carb and spraying a little in the plug hole. when i flooded it by choking it with my hand it back fired. other than that it has acted like it even wants to start. any ideas how i can get this baby started?
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if i hold the throttle wide open it will back fire after turning about 20 secs. any idea what this is? anything i can try? do the carbs just go bad? help!!!!!
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If you have spark and are just not getting it to turn, it sounds like it may be time to rebuild the carb or possibly the motor itself (check the compression for that).
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the carb seems to be working. i got a people 2t too. they look to have the same engine on them. i was gonna switch carbs to see if that did the trick. but the round cylinders for the throttle are different sizes. i just had the idea to take the entire piece off the throttle this morning. gonna do some more changing around and see. i burned up the starter also but a gy6 starter bolts right up!! and seems to have more torque. gonna go back out and try some more things. how can i check for compression without a gauge? i had already put my finger over the spark plug hole while turning the engine to see if it was getting gas in the cylinder and over the hole in muffler.............................................
WHAT HAPPENED TO THE OLD SCHOOL PEOPLE? SHAKA............WORDSLINGER......ART........BATMAN............JUICE.......ZOMBIE!!!! HELP!!!!!
let me find out u guys went and got a vip scooter
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You may not want to give it too much gas you'll flood the engine and its almost imposible to start. Try just using the kick start up on the main stand. You shouldnt need to touch the throttle at all. When its cold out thats the only way my people will start. When it sits for even a week or so its much harder to start. I have to kick it over and over. Its worth a try and it doesnt burn up the starter.
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Hrm. Sounds like the low speed jet may be clogged - The orifce is TINY, easy to block. May want to check that the float is moving too.
Take it off, take it apart, HOSE IT DOWN in every hole with carb cleaner. BLOW out all the holes with a compressor. Set all the mix screws to stock and put it back on.
If it is a 2 stroke, check out the reeds to see if they are bent/chipped/mangled/dirty.
If it doesn't fire after spraying starting fluid in the plug hole - Something else may be a problem. Make sure the park plug is fresh and properly gapped.
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''when i flooded it by choking it with my hand it back fired.''
may be the mix is wrong. possibly disable the pre-mix system. I have been meaning to do that on my s9. I never felt comfortable with it. :P
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''when i flooded it by choking it with my hand it back fired.''
may be the mix is wrong. possibly disable the pre-mix system. I have been meaning to do that on my s9. I never felt comfortable with it. :P
take the oil pump loose? good idea!!! im going to have to try that. just mix it myself and see if that gets her started!! now how do i do that? just unhook the hoses going to it and plug them?
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Check to see if there is a cable going to the oil injector as well. On my 50cc scoot, the throttle cable had a splitter that went to the oil pump. If so, you'll want to disconnect that.
Then just carry a bottle of 2cycle oil with you.
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Check to see if there is a cable going to the oil injector as well. On my 50cc scoot, the throttle cable had a splitter that went to the oil pump. If so, you'll want to disconnect that.
Then just carry a bottle of 2cycle oil with you.
so just take the cable loose mix the gas and try to start? no need to mess with the jets/
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havent taken the cable loose yet but it seems close to starting. every 10 secs or so it will back fire while trying to start. should i adjust the carb rich or lean?
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Won't need to rejet for doing the premix thing. No worries!
The easy way is to check the service manual for the stock settings, or ask the forums. Dialing a carb in with no guidence is rough.
I'd start lean and richen (loosen) the mixture screws 1/8th turn at a time. When it fires up, stop it immediately! Then richen it up 1/2 a turn or so to prevent damage. From there you can dial it in:
- High speed mix: Under throttle, generally lean it out until you hit max rpm, then loosen 1/8th or so
- Low speed: Battle with that and the idle set screw to find a reliable idle at the rpms you desire
It won't be easy - make sure you have a full battery!
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Hey Dre-
I saw you posting over at SI also. Did you get it started yet? Have you tried starting fluid or carb cleaner down the intake? It it has spark and compression it will always at least fire a couple turns. Otherwise, you need to get a compression tester. Anything less than about 90 psi and it won't run. You can pick up a cheap compression gauge at Harbor Freight for less than $25. If you aren't getting anything at all out of it and you have good spark, you don't have compression. Good luck!
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Hey Dre-
I saw you posting over at SI also. Did you get it started yet? Have you tried starting fluid or carb cleaner down the intake? It it has spark and compression it will always at least fire a couple turns. Otherwise, you need to get a compression tester. Anything less than about 90 psi and it won't run. You can pick up a cheap compression gauge at Harbor Freight for less than $25. If you aren't getting anything at all out of it and you have good spark, you don't have compression. Good luck!
YOU'RE ALIVE!!!!! yes ive tried starting fluid right in the intake. it will just backfire a few times. i guess im gonna have to get a compression tester. im gonna pull the intake first to check the reeds as soon as this rain stops
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Hey Dre-
I saw you posting over at SI also. Did you get it started yet? Have you tried starting fluid or carb cleaner down the intake? It it has spark and compression it will always at least fire a couple turns. Otherwise, you need to get a compression tester. Anything less than about 90 psi and it won't run. You can pick up a cheap compression gauge at Harbor Freight for less than $25. If you aren't getting anything at all out of it and you have good spark, you don't have compression. Good luck!
what kind of compression gauge do i need? one for a car will work?
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If you are in the US, swing by a Western Autoâ„¢, Autozoneâ„¢ or the like - They actually lend those out for free!
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If you are in the US, swing by a Western Autoâ„¢, Autozoneâ„¢ or the like - They actually lend those out for free!
thanks!!! gotta love this site
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low compression is the problem!! thanks!!
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That's both good and bad... the good part, you know what needs to be done to fix it... the bad, fixing it. Might need to have new rings and redo the gaskets... worst case is boring the cylinder walls and getting a new piston. However, would make it a nice 70cc with the right equip.
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That's both good and bad... the good part, you know what needs to be done to fix it... the bad, fixing it. Might need to have new rings and redo the gaskets... worst case is boring the cylinder walls and getting a new piston. However, would make it a nice 70cc with the right equip.
i just bought the malossi kit...... we shall see if i can get her on!!
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New bucket for the 50cc? If it came with a piston (with rings installed) and head, you are so set. 2-4 hours all up - easy. No cam chain to deal with, and because it is so small you can use your hand to compress the piston rings! LOL!
Few items:
- Cross torque the head bolts when reassembling to prevent warping (just like you would on a 4 lug tire)
- USE A TORQUE WRENCH!!!!
- if you are upping displacement (50-70cc), you WILL need to at least rejet the carb. You may even need a bigger carb. Good News - It WILL be faster ;D
- For the first few tanks, add a little extra 2 stroke oil to the premix for breakin - Run the carb a lil rich too.
If you need help or words of encouragement we're right here ;D
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Cool man
Let us know how it goes ;D
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its a new beast!!