50cc dies to 10mph when engine hot - Page 2

sc00ter · 08-08-2019, 08:50 AM

One thing to pay attention to if you decide to remove the evap/emission system, and I hope the dealer is aware of this also. Odds are the emission system is tied into the exhaust catalytic converter, and the evap/emission system supplies the needed air for the catalytic converter to operate properly. If you just remove the evap system the exhaust will not get the needed fresh air for the cat to operate properly and the scooter will run like its underwater. I've seen some weird emission systems! Some simple, some extremely complicated.

skyrider · 08-16-2019, 08:41 AM

Finally got the scooter Wed. The shop rode it for 1/2 hour and couldn't get it to bog out. They said everything looked good and the slight rattling came from a long bolt in the motor mount bushing under the motor. They said that the evap system could be disconnected from the back lower of the gas tank, but I couldn't find it and called A1Racing technical support and looking at the parts diagram they said it didn't have an evap system. They said I was prob riding to hard and actually the carb couldn't fill fast enough so it essentially "ran out of gas". So bottom line, I shouldn't try to redline the scoot for long periods of time. That makes sense, as the day it bogged out to my location at full speed, then after 45 min when I left to return home I rode slower and no problem!! Haven't ridden since, so still not sure. So for $115 I learned there was nothing wrong with the scoot, and for free from calling A1 I learned the probable cause of the problem. Kudos of thanks for Scooter!!!

sc00ter · 08-16-2019, 09:54 AM

Loosen the gas cap and go and punch it, and see if the problem comes back. I've never heard of a scooter running low on fuel during WOT. I suspect either a fuel line is getting pinched while you are sitting on it (related to the loose bolt for the engine?) or the fuel tank is getting vapor lock from a clogged tank vent, hence the loosening the fuel cap and going for a WOT run. There is also a slight chance the main jet could be partially gummed up, the carb float could need adjusting (they usually get damaged from people manhandling the float bowl-me included!) or..... Anyways, try loosening the fuel cap and going for a WOT run. That "Not designed for WOT runs" sounds strange!

skyrider · 08-17-2019, 08:06 AM

Will loosen the cap and run it hard! Thanks for continuing to offer suggestions!

sc00ter · 08-17-2019, 10:55 AM

It just sounds like a fuel delivery issue to me. Like a fuel line is getting pinched or there is a venting issue. There is no reason why you shouldnt be able to run WOT all day if needed. Just go back thru my suggestions and try them one at a time. Again, let us know what your findings are.

skyrider · 08-22-2019, 07:10 AM

The previous "bogging" fuel issue happened with the engine full to 3/4 full, not overfull though. Yesterday I did a the very hard test ride (with the cap tight) that I previously did with just 1/4 tank left and no deceleration problem. There is an overflow hose just below the gas cap and that is clear, so perhaps that acts as a type of vent. When I fill it I'll do another test ride with the cap lose and see what happens. The fuel line doesn't seem to be pinched.

08-16-2019, 08:41 AM	#17
skyrider Join Date: Jul 2013 Location: richmond,VA Posts: 94	Finally got the scooter Wed. The shop rode it for 1/2 hour and couldn't get it to bog out. They said everything looked good and the slight rattling came from a long bolt in the motor mount bushing under the motor. They said that the evap system could be disconnected from the back lower of the gas tank, but I couldn't find it and called A1Racing technical support and looking at the parts diagram they said it didn't have an evap system. They said I was prob riding to hard and actually the carb couldn't fill fast enough so it essentially "ran out of gas". So bottom line, I shouldn't try to redline the scoot for long periods of time. That makes sense, as the day it bogged out to my location at full speed, then after 45 min when I left to return home I rode slower and no problem!! Haven't ridden since, so still not sure. So for $115 I learned there was nothing wrong with the scoot, and for free from calling A1 I learned the probable cause of the problem. Kudos of thanks for Scooter!!!
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08-17-2019, 08:06 AM	#19
skyrider Join Date: Jul 2013 Location: richmond,VA Posts: 94	Will loosen the cap and run it hard! Thanks for continuing to offer suggestions!
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08-22-2019, 07:10 AM	#21
skyrider Join Date: Jul 2013 Location: richmond,VA Posts: 94	The previous "bogging" fuel issue happened with the engine full to 3/4 full, not overfull though. Yesterday I did a the very hard test ride (with the cap tight) that I previously did with just 1/4 tank left and no deceleration problem. There is an overflow hose just below the gas cap and that is clear, so perhaps that acts as a type of vent. When I fill it I'll do another test ride with the cap lose and see what happens. The fuel line doesn't seem to be pinched.
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