One for the experts; all tests pass, but no start By wutzthedeal (Read 2,097 times)

[wutzthedeal]

Hey guys,
I tried to get help with this on another forum, and I did, but the thread was so inflated, I just wanted to come here and start over, and get some different perspectives (although I know some people from there are here, too).

Long story short; started my TaoTao 49cc CY50-A 2012 (VIP Future Champion) a few nights ago to let it warm up. After about three minutes, it died. That had only happened once before, and before, when I went to restart it, it flooded. So, I took the air filter out, cleaned and dried it, and put it back. No problems for a week. This time, it would not restart and hasn't started since. It did not flood when I repeatedly tried to restart it. I've run plenty of tests which I'll list below:

Got spark against motor, tested with two plugs known good, screw is tight for carb fuel bleed valve (the hose with the metal coil around it), compression is good enough to blow my thumb off of the hole, battery is new and plenty strong and kept up with battery tender; turns over and over. Kick start does no better, just turns it over. Cleaned spark plug, dried it, put it back in, tried to crank a few times and it did come out moist and smelled like fuel. All lines were checked and tested for tears or slipping off. Removed carb and found that during my troubleshooting, I had put the needle back on wrong and bent it, and the diaphragm slot was not lined up; fixed both of those and confirmed they were operating correctly. Didn't have carb cleaner, so just did a light cleaning with wire and alcohol but it was really clean anyway (I expect from regularly using Seafoam). After putting carb back on, no change. Starter fluid did not help; sprayed it liberally up the air intake, behind the filter, on two separate occasions. Still never tried to fire. Also, there is no change in the sound of the engine trying to start when I am full throttle or no throttle.

Notes; when I took carb off, a couple of ounces of fuel poured out. When attempting to start, it never even "almost" starts. I just turns rhythmically over and over. I have a video of it and how it sounds, and photos of the carb while it is out. I replaced the CDI; that didn't help. I'm truly at a loss. On the other forum, they almost had me convinced that it has to be a cracked piston or rings but on this forum, people are suggesting that if it blows your thumb off of the hole, it's got enough compression to run, so if that's the case, it's not a compression problem.

Please tell me there is a miracle worker here; I miss riding my scooter so much! It's driving me crazy, man! Thanks for reading.

[justbuggin]

have you crank it over with the plug out sounds like you have flooded the thing when you pull the plug and it is wet with gas you will need to crank it over a few times to blow out the extra gas in the cylinder you say youn have cleaned and dry the plug i will say get a new plug as well

[wutzthedeal]

Jan 25, 2013 23:35:56 GMT -6 justbuggin said:

have you crank it over with the plug out sounds like you have flooded the thing when you pull the plug and it is wet with gas you will need to crank it over a few times to blow out the extra gas in the cylinder you say youn have cleaned and dry the plug i will say get a new plug as well

No I've never tried that or even been advised to try it. I have two spark plugs that were both functional before this problem and that give good spark now. Before, when I flooded it, I could smell the fuel... some even came out (I guess through the air filter). Now, for the past 100 cranks or so, there has been no smell of fuel so I doubt it's flooding. Do you think I should still try to crank it with plug out?

[terrilee]

this is stupid idea
but sometimes my ideas works

have u jumped the solenoid yet?
plus it may seem like ur starter is working,
but it might not be fully engaged.

if when u jump the solenoid and it starts
well you can rule out the starter being the prob.

have you even jumped it with a car?
if not MAKE SURE THE FREAKING KEYS ARE OUT OF THE CAR
OR IT WILL FRY UR SCOOT

[justbuggin]

yes i still say give it a try and yes get a new plug it is very hard to get a fouled plug cleaned to where it will work under pressure

[tvnacman]

Ok , this my trick . Pull the carb off , pull the plug spray with contact cleaner , brake cleaner or put in a new plug . Fully charge your battery . When the above are done and only when above are done ! Crank the scooter and look at the valve moving , stop , while cranking dump a cap full of gas in the hole . It should do something , report back . Your welcome to call me I will be happy to talk you through on the phone .

Did you do the valves , I will ask you again to recheck them .

John

[wutzthedeal]

No haven't jumped it with a car. New, powerful battery, I could get 100 cranks out of it before it weakens... still use a car? Will try the spark plug out thing. John, cap full of gas in what hole? My carb doesn't open. Is the hole you're talking about somewhere else? I did adjust the valves, twice (using part of a soda can for .0035 or so) so you're saying open that back up and dump fuel in when a valve rises or?

[tvnacman]

remove the intake manifold , then you can see the intake valve inside the hole .

I would not rely on the soda can thing , get feeler gauges .

John

[Bashan]

• Is the spark a dull looking orange or bright white/blue. If it's the former it won't start the scooter.
  
• Are you sure you're getting fuel to the carb? Follow these tests to make sure.
  
• Did you check your float bowl valve? If it's stuck the scooter won't start.
  
• I would check the compression with a good tester. Your finger doesn't qualify.
  

[/b]

[wutzthedeal]

Ok tried to jump with car; failed. Removed plug and put in old plug; failed. Only difference is now, the plug does not get moist or smell like fuel since I (lightly) cleaned the carb. I do not have the ability right now to get feeler gauges or a compression tester, so that's out. I read on this forum that if it blows your finger off of the hole, it's enough to run the scooter. Is that wrong? And I can't get to my float bowl area, if I'm understanding the anatomy right. The bolts/screws to access the inner carb have no heads. I'll post a vid that shows start attempt. Also, what is the big, fat hose that looks like it has something the size of a fuel filter on it but runs to nowhere? (It runs down along the right side of the bike, from an area where three other hoses run, all black, two large one small). Is that supposed to be open and connected to nothing?

[wutzthedeal]

[wutzthedeal]

Bashan, I know that I get fuel to the carb because I took the line off and cranked it, and fuel dribbled out in a steady stream. When I stopped cranking, the fuel stopped, so that tested out the fuel delivery/vacuum, right? At least up to the point of the entrance to the carb. And I guess I need to go look at the spark again on both plugs, but I was pretty sure it was a crisp blue.

[buford1488]

definitely a spark issue..

[wutzthedeal]

Jan 26, 2013 14:28:20 GMT -6 buford1488 said:

definitely a spark issue..

Actually you're right; not getting spark at all now, where I was getting it from both plugs yesterday morning. Tried two separate coils and three CDIs (one is brand new). Well this changes everything. But the fact is I had spark when this problem started, so it stands to reason that this is now a 2nd issue.

[kz1000st]

I second that. First try a brand new plug gapped at about .025 inch. It's not firing under load which is why your plugs get wet. I had to replace a CDI unit on a 50cc Lance I owned briefly. It sounded like that when I got it. New plugs would fire it.