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Post by revwhite on Mar 19, 2012 17:50:20 GMT -6
I just put in a new GY6 150 cc, and it has started to have a Slight miss, and backfire on deceleration. I haven't ajusted the valves after breakin yet, but before I do my question is; my original engine had the receculating line off valve cover and this engine doesn't; should I replace the CDI, and Carb that came with the new engine; could this be the problem? Thanks Guys for any help in this matter!!!
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Post by Alleyoop on Mar 19, 2012 18:20:09 GMT -6
Backfire on Deceleration is caused by a LEAN condition. The most common cause is it is LEAKING by the Flange where it connects to the MOTOR. Also did you connect the Vacuum hose to the ACV diapghram, I presume it is a CVK carb and most of them have a ACV diaphgram. The ACV VALVE cuts the air when you let go of the throttle so it does not run LEAN from the quick closeing of the throttle.
Alleyoop
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08 roketa special edition 150
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Post by roketafan on Mar 19, 2012 19:50:16 GMT -6
Most likly vac leak some where like alley said start at intake
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Scooter Doc
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Post by sprocket on Mar 21, 2012 10:44:46 GMT -6
Alley has nail it... ACV valve most likely
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Post by revwhite on Mar 23, 2012 5:04:10 GMT -6
Thanks, VAC Leak.
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Post by Bashan on Mar 24, 2012 2:11:34 GMT -6
FYI for those that may not be aware of this, a vacuum leak can cause air cut valve (ACV) problems. The valve runs off of the vac line from the intake manifold that runs to the vacuum fuel valve:
If you check your vacuum lines for leaks and they're adequate it could be the ACV valve itself. Take the two screws out and inspect the diaphragm for cracks. Rich
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Post by kz1000st on Mar 25, 2012 16:36:14 GMT -6
Or it's that darn O-ring between the intake manifold and insulating spacer
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Post by SABER on Mar 30, 2012 13:45:48 GMT -6
Backfire on Deceleration is caused by a LEAN condition. The most common cause is it is LEAKING by the Flange where it connects to the MOTOR. Also did you connect the Vacuum hose to the ACV diapghram, I presume it is a CVK carb and most of them have a ACV diaphgram. The ACV VALVE cuts the air when you let go of the throttle so it does not run LEAN from the quick closeing of the throttle. Alleyoop You got that right, On my way home from work today I lost one of the two cap nuts that holds the exhaust on my 150. Back fire all over the place plus the unpleasant sound of the exhaust leak as I nursed her home. Glad its the weekend. |
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Post by sprocket on Mar 30, 2012 14:20:46 GMT -6
replace the copper ring gasket with a full face like the picture.. you will never loose a nut again. Attachments:
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Post by tvnacman on Mar 30, 2012 14:42:25 GMT -6
replace the copper ring gasket with a full face like the picture.. you will never loose a nut again. Gee I just got 20 pcs of this gasket , with nuts and studs to go with it . John |
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Post by Alleyoop on Mar 30, 2012 15:00:12 GMT -6
John,
I Pmed you would like a couple just in case.
Alleyoop
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Post by SABER on Mar 31, 2012 6:28:09 GMT -6
replace the copper ring gasket with a full face like the picture.. you will never loose a nut again. I wish that was the case. I put that gasket on last year. I just need to add a plus 5 or 10 to the torque spec when the replacement nuts show up. |
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..BAD TO THE BONE..
