Carb Questions

SeattleSeahawks · 02-25-2015, 04:17 AM

What could be wrong with my scooter?

01 Roketta 250cc

It wont start unless i spray starting fluid into the carb.

My air box fell off the part that connects to the carb. i then drove it about 20 miles home. the rubber housings completely snapped.

i have tried cleaning it, but still wont start over without starting fluid. could this be because the air box isnt connected? i'm not sure if that is a dumb question but at this point i'm lost. also when i start it and get it running it wont idle and sounds like there is a whole in my muffler.

what should be my first steps, or parts i need to replace besides my air box obviously.

please help i miss my scooter!!!

thanks
Ian

Shadowfire · 02-25-2015, 11:11 PM

You have a carburetion problem. Your ignition and compression are good, since it wants to fire up if you use starting fluid.

First thing you'll want to do is find out why the airbox snapped off. There should have been 3 bolts attaching it to the engine.

Then, figure out why you have a carburetion problem.
1. Is there gas? No - fill it up.
2. Is there gas in the float bowl? After cranking it for 10 or so seconds, open up the carburetor drain screw. If little or no gas comes out, you have a plugged fuel filter, plugged fuel line, no vacuum to the fuel pump, or fuel pump is toast.
3. If there WAS gas in the float bowl - you most likely left the bike with gas in the carburetor long enough for it to turn into cheesecake. You either service the carburetor and clean it up, or buy a new one. If the carburetor is clean, check the fuel enricher, it may be damaged and stuck in the closed position, which means you have no choke, making it impossible to start it when it is cold.

SeattleSeahawks · 02-26-2015, 01:41 AM

Thanks for the reply!

This is what fell off, and needs to be replaced.

http://img.auctiva.com/imgdata/4/7/8...05233409_o.jpg

The one on the right

i should be getting this part in the mail any day now, and then i will check out all of the things youve listed above. thank you so much for the help

rks · 02-26-2015, 09:17 AM

I believe if you get an air box back on it, you'll find it will start just fine.

As it is now, you are getting far too much air, due to the lack of restriction that the air box was providing. This is why it won't idle also....a/f ratio way off. If you covered most of the carb opening with a gloved hand or the like, and hit the starter, I think you'll see it fire up.

I would never use starting fluid. Get some kind of air filter on it.

Scoot703 · 02-26-2015, 10:03 AM

how do i create my own thread ik im stupid lol i just need help my engine wont start and i need to post a thread

Shadowfire · 02-26-2015, 10:27 PM

If the air box is off, it WILL start up, it will just run lean. Note that during startup, you should NOT be opening the throttle. The bike needs the vacuum to operate the fuel pump (at least until the float bowl is full) and will not be able to get fuel during cranking if it isn't in the idle position. The YY250T has an automatic enrichment circuit, and should start right up with the throttle in idle (unless, like right now, it's -7F and you have 15W40 oil in the engine... it WILL start, but it isn't easy, the oil is probably as thick as molasses, and it stalls out without any gas until it warms up a bit)

Irish · 06-23-2015, 11:53 AM

As I have posted on other threads-Be careful with starting fluid! I sometimes use it myself (especially when I lived in N.H. ) but many engines have been ruined by it! It also supposedly dries out seals.

Irish

XenoMorphicRex · 07-21-2017, 02:57 AM

Quote:

Originally Posted by SeattleSeahawks

What could be wrong with my scooter?

01 Roketta 250cc

It wont start unless i spray starting fluid into the carb.

My air box fell off the part that connects to the carb. i then drove it about 20 miles home. the rubber housings completely snapped.

i have tried cleaning it, but still wont start over without starting fluid. could this be because the air box isnt connected? i'm not sure if that is a dumb question but at this point i'm lost. also when i start it and get it running it wont idle and sounds like there is a whole in my muffler.

what should be my first steps, or parts i need to replace besides my air box obviously.

please help i miss my scooter!!!

thanks
Ian

The "J" shaped tube, AKA the snorkel, has a fine mesh sub-filter in the end that attaches to your carb, this restrict airflow to some extent. when the air box came off, you lost that restriction, cause your engine to go lean. Basically your fuel air mixture is screwed up so I'm not surprised that you scooter wont run right, and shadowfire is also right, about carburetion problems. you have 2 options, replace the carb, or rip it apart, and clean it, if its been sitting for awhile, the gas will have varnished the passages in your carb. They can be cleaned using carb cleaner, and precision pipe cleaners, the pipe cleaner are made of copper, and are hard to come by. not many stores carry them. if you have the $, replacing the carb would be the easiest solution. but cleaning and rebuilding the carb you have will work too. yes I said rebuild, though you can sometime get away with disassembling a carb without a rebuild kit, I don't recommend doing it without said kit.

XenoMorphicRex · 07-21-2017, 03:01 AM

Quote:

Originally Posted by Irish

As I have posted on other threads-Be careful with starting fluid! I sometimes use it myself (especially when I lived in N.H. ) but many engines have been ruined by it! It also supposedly dries out seals.

Irish

I agree, I don't trust starting fluid, is mainly Ethel-Ether, and that stuff destroys seals and gaskets.

crawford · 09-03-2017, 10:08 PM

are you sure fuel getting to float bowl pull line off at carb is fuel coming out no open gas cap see if it helps if all that ok you need to open carb clean low and high jets use a very thin wire poke it through blow through it get air put it back together and try again it should fire up and run.

02-26-2015, 09:17 AM	#4
rks Join Date: Dec 2013 Location: Western New York Posts: 454	I believe if you get an air box back on it, you'll find it will start just fine. As it is now, you are getting far too much air, due to the lack of restriction that the air box was providing. This is why it won't idle also....a/f ratio way off. If you covered most of the carb opening with a gloved hand or the like, and hit the starter, I think you'll see it fire up. I would never use starting fluid. Get some kind of air filter on it. __________________ 2011 Jonway 150cc..16,109 breakdown free miles, and counting
	0

06-23-2015, 11:53 AM	#7
Irish Join Date: Dec 2014 Posts: 738	As I have posted on other threads-Be careful with starting fluid! I sometimes use it myself (especially when I lived in N.H. ) but many engines have been ruined by it! It also supposedly dries out seals.Irish
	0

02-25-2015, 11:11 PM	#2
Shadowfire Join Date: Feb 2015 Posts: 121	You have a carburetion problem. Your ignition and compression are good, since it wants to fire up if you use starting fluid. First thing you'll want to do is find out why the airbox snapped off. There should have been 3 bolts attaching it to the engine. Then, figure out why you have a carburetion problem. 1. Is there gas? No - fill it up. 2. Is there gas in the float bowl? After cranking it for 10 or so seconds, open up the carburetor drain screw. If little or no gas comes out, you have a plugged fuel filter, plugged fuel line, no vacuum to the fuel pump, or fuel pump is toast. 3. If there WAS gas in the float bowl - you most likely left the bike with gas in the carburetor long enough for it to turn into cheesecake. You either service the carburetor and clean it up, or buy a new one. If the carburetor is clean, check the fuel enricher, it may be damaged and stuck in the closed position, which means you have no choke, making it impossible to start it when it is cold.
	0

02-26-2015, 10:27 PM	#6
Shadowfire Join Date: Feb 2015 Posts: 121	If the air box is off, it WILL start up, it will just run lean. Note that during startup, you should NOT be opening the throttle. The bike needs the vacuum to operate the fuel pump (at least until the float bowl is full) and will not be able to get fuel during cranking if it isn't in the idle position. The YY250T has an automatic enrichment circuit, and should start right up with the throttle in idle (unless, like right now, it's -7F and you have 15W40 oil in the engine... it WILL start, but it isn't easy, the oil is probably as thick as molasses, and it stalls out without any gas until it warms up a bit)
	0

09-03-2017, 10:08 PM	#10
crawford Join Date: Jun 2015 Location: Dandridge,tn 37725 Posts: 57	are you sure fuel getting to float bowl pull line off at carb is fuel coming out no open gas cap see if it helps if all that ok you need to open carb clean low and high jets use a very thin wire poke it through blow through it get air put it back together and try again it should fire up and run.
	0