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#1 |
![]() Join Date: Jun 2016
Posts: 5
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Pulling on carb solved engine die issue at throttle
Ok so I had a working scoot and all of a sudden I went to start it to take for a ride. Started fine. Idled fine for warm up then as I pulled from driveway and gave it throttle it would die. I would start it again and as soon as I give it throttle it revs and dies. After reading everything, it could be the valve clearance in need of adjustment. Maybe even a petcock. Perhaps a bad ignition cable, spark plug, CDI or even some other stuff with the carb. All those things except carb are new and have been replaced prior to issue. While I was ready to pull the carb out I notice the engine sounding better as I tugged on the carb between the two rubber intake and exhaust tubes. Then I said let me try giving it throttle as I pull a little up on the whole carb assembly. Sure enough it did not stall. I let go of the carb and checked the hose clamps and all and all seems tight. Once again fired up and gave throttle and it died. The I did same while slightly tugging up on carb or perhaps the airbox attached to the carb and it revs and spins wheel fine. It does not die at throttle when I tug a little on carb. Any idea what I'm dealing with here? Does position of carb or angle have effect on how things run?
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#2 |
![]() Join Date: Jul 2013
Location: richmond,VA
Posts: 94
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While I'm no Bull, Blueboy, CapeCodScooter, my thoughts are that you have an air leak. Have you tried removing then reinstalling the carb?? Perhaps check all the air connections from the carb out thru the hoses to their origin. Wish those fellows above would respond!!
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#3 | |
![]() Join Date: Dec 2014
Posts: 738
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#4 |
![]() Join Date: Oct 2008
Location: Hyde Park, NY
Posts: 1,119
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You have a cracked intake manifold. You are probably pulling the crack closed when you tug up on the carb. Been there.
__________________
2008 Eagle Milano 150- 9,679 miles 2009 Honda Rebel 250- 10,434 miles 2009 CF Moto Fashion- 16,023 miles 2009 MC-114 50cc Cub Clone- 4,317 miles twowheeler.yolasite.com/ That's 30,049 China Scootin miles and Counting. |
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#5 |
![]() Join Date: Jun 2016
Posts: 5
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Would I see this crack on the outside ? What is that little flexible air hose line that goes to the air filter box? If I pull it or press tighter where it's clamped on that helps engine stay on at revs as well. Maybe just coincidence.
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#6 |
![]() Join Date: Feb 2015
Posts: 121
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You will probably see it once you take the manifold off. To test it, spray a little starter fluid at the manifold while the engine is idling. If idle speed changes, you have a leak and need a new manifold as previously suggested.
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#7 |
![]() Join Date: Jun 2016
Posts: 5
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Thank you guys. I will check when I have some time. Just in case I ordered a new manifold for like $8. I got one with single outlet since mine was single. Would I have benefited getting a dual outlet instead?
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#8 |
![]() Join Date: Jul 2011
Location: Connecticut
Posts: 493
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Agreed KZ, sounds like a cracked manifold.
__________________
2011 Roketa MC-23-150 4T 150cc 157 qmj 24mm carb w 115 main jet and paper cone air filter Manual petcock w Tygon fuel lines Scrappy Dog Scooters Retro-slash stainless straight-thru exhaust RED spring clutch Adjustable CDI (brand unknown, it's blue and red and works great!) KOSO high performance variator w 12g sliders Gates Powerlink 835-20-30 belt GPS verified 65mph on flats. |
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#9 |
![]() Join Date: Jun 2016
Posts: 5
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Yup wish it was easy as that. I pulled the manifold off and looked at it could not find any cracks or anything out of ordinary. Put it back on same thing. I put it on center stand. Give it throttle and it starts going but as soon as I get to full throttle or close to it then it just dies. Same thing if I rev it to full throttle just dies. I even did the painful procedure of adjusting valves just in Case (lots of plastic and screws to remove). No dice there. Yet as I said if I twist it little side ways (the carb) it works better. Got new carb coming in. Too much hassle not to spend another $25 just to eliminate a faulty carb. Are they hot swappable or do I have to prep it some how?
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#10 |
![]() Join Date: Jul 2013
Location: richmond,VA
Posts: 94
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So I googled "scooter dies" and got this:
http://scootdawg.proboards.com/threa...er-starts-dies So it could be the carb. Perhaps you should explore solutions given to similar described problems!! And yes, could be a stuck carb so a new one or cleaning the old one is a possible solution. What do they say, "Gas, spark, battery???" or something like that, LOL! ![]() ![]() ![]() |
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#11 |
![]() Join Date: Jun 2016
Posts: 5
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Thanks for the link. Funny when I searched using "dies at throttle " I got different results. Any way since I already have a new carb I might throw that in and then repair the old one when I have time to fiddle.
Do I need to do anything special before or after I mout the brand new carb between the intake hose and the filter ? Will it work right away or does it need priming or something? Also I got one of those uni performance filters with the new carb is that better to use then stock air box? The new carb has 85jet I think. |
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#12 |
![]() Join Date: Jul 2011
Location: Connecticut
Posts: 493
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Uni-style filter and #85 main jet should do fine. You should apply vacuum to ( or suck on the vacuum line) the fuel switch/petcock for about 10sec to "prime" the new carb, or just crank it over a bunch.
Make sure you start with the mixture screw at 2 &1/2 turns OUT.
__________________
2011 Roketa MC-23-150 4T 150cc 157 qmj 24mm carb w 115 main jet and paper cone air filter Manual petcock w Tygon fuel lines Scrappy Dog Scooters Retro-slash stainless straight-thru exhaust RED spring clutch Adjustable CDI (brand unknown, it's blue and red and works great!) KOSO high performance variator w 12g sliders Gates Powerlink 835-20-30 belt GPS verified 65mph on flats. |
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