wont crank, at wits end

[neo71665]

Ok so my buggy ran fine three days ago and has been sitting covered since. I went to crank it up yesterday and it won't fire up. Will crank if I put a bit of gas down the carb and run it out. Gas poured down carb to make it run come out of tank on buggy.

gas tank vent is open

fuel flow to carb is fine, filter clean

Carb is clean, 3 times now

Got spark

air filter clean

My thought since it runs pouring gas down carb throat it screams a clogged carb passage or jet but this carb is clean enough to eat off of. I've taken it apart to clean 3 times already and have ran it though the ultrasonic cleaner 2 times. The auto choke is new but I installed it before it decided to act stupid and has ran fine with it. I'm at my wits end with this thing. I know it's something stupid simple I'm overlooking because I'm frustrated. Open to suggestions.

[OLDKID]

Automatic choke not working or fuel circuit for choke obstructed .

[x-bird]

if you haven't, disconnect fuel line at the carb, put it in a can etc. and crank it. if you're getting a really slow fill of the fuel lines it could be the petcock. i've had the seal at the "handle" come apart several times and chunks of it plug the passages inside. all looks good, but wont' pull enough fuel to run.

[scjeep4.7HO]

Do you have compression?

[neo71665]

Gonna try a spare choke. The passages are spotless. It's a new carb that's been cleaned 4 times now (cleaned it once before I put it on) 3 times last night.


Fuel pours out the petcock. I've opened it up in a cup and it flows what seems like fine and I have clear fuel hose/filer I can see it flowing in. I didn't tear it down last night but I did pull it out of the tank and check the screen and it was fine.

I haven't checked compression but since it cranks and runs fine as long as it has gas being poured in it I'm pretty sure it is fine. I'm still leaning towards a fuel delivery/carb problem, i've been wrong before.

Thanks guys. If i'm not wore out and the rain stops I'll work on it some more after we get home from the dr today.

[neo71665]

Ok so I'm looking for the specs on the resistor if somebody can confirm. I found a place that claims it's 10.2ohm 5W.

Reason I ask is because I'm cheap. All the ones I find marketed for a gy6 are $15-20. I can pick up one in those specs for under $5 if it's the correct specs.

[scjeep4.7HO]

might be a silly question but are the fuel lines in the right location? Is the float working correctly in the carb?

[neo71665]

Nothing silly to me at this point. I don't care if it's did you change the plug and check the gap (yes I did). I just want to get it back running.

It all was working just fine before this weekend fine as walk out and hit the key cold start and it fire up no problems at all. The carb was swapped out about 4 months ago with a 26mm. The choke I put a new one on it a month ago. Both are new parts but I know one or both could have gone bad. As far as I know only one place on the manual petcock (also new under 2 months old) to hook a fuel line and only one place on the carb. The fuel bowl seems to be filling up just fine.

If the rain stops and it warms up a bit today I'm gonna go out and put that other choke on it.


Not that it matters I went through this thing right after I got it and been replacing parts. The only part that isn't new in the fuel system is the tank and I did vat it and have it coated back in july. So everything from the intake manifold to the petcock is new as of at least july this year. I did replace the fuel filter and cleaned the air filter the other night.

[scjeep4.7HO]

If it runs by putting fuel into the carb then it has to be a fuel supply issue somewhere. Either in the actual fuel line or something. the intake manifold not seating against the head? did you happen to leave the filter tube type thing in the tank from the old vacuum petcock?

[tim]

I am assuming it is gravity feed if so are you able to disconnect your fuel filter input and fill the filter up with syringe and hold it above the carburetor then if it does the same thing this will eliminate the problem being North off the filter.next step is to empty bowl and blow through carburetor input hose,with no gas to hold up float air should pass through freely.
Good luck

[neo71665]

Thanks for the suggestions guys. It's raining, cold, and I'm on meds that suppress my immunity so I'm not going out in it and trying to get sick. I promise I'm not just being a lazy keyboard commando. The past year I'm had 4 major surgeries and frankly seen enough doctors I'm trying to stay away from them and hospitals as much as I can. My son's car is on a rotisserie in the shop so I can't just pull it in there and work comfortably. I don't care how big your shop is when you build it, after a year it will always be 8 times smaller than you "need".

Originally Posted by scjeep4.7HO

If it runs by putting fuel into the carb then it has to be a fuel supply issue somewhere. Either in the actual fuel line or something. the intake manifold not seating against the head? did you happen to leave the filter tube type thing in the tank from the old vacuum petcock?

Strainer from old petcock not in tank. I didn't get a chance to work on it today but I'm 99.99% sure the intake is seated and sealed. I will double check because like I said I'm open to any suggestion.

Originally Posted by tim

I am assuming it is gravity feed if so are you able to disconnect your fuel filter input and fill the filter up with syringe and hold it above the carburetor then if it does the same thing this will eliminate the problem being North off the filter.
Good luck

Yes gravity fed but I did take an air hose and hook it to the vent on the gas cap trying to pressurize it with about 10psi to see if I could blow anything out before I rebuilt the carb the first time the other night. That managed to flood it out pretty bad (yes I knew it would). Thats when I tore it down the first time. No it did not collapse the strainer or filter putting it under pressure. I checked to make sure they both flow afterwards.

I have not disconnected the tank but I have a hose on a funnel just for that purpose. It was on my list of things to try if I could work on it today.




I went ahead and ordered a new enrichment valve. I'm really leaning towards that or the resistor is bad personally. Even if it isn't I'm gonna machine one of the old ones out and use parts to build a cable operated one.

[tim]

Sorry to hear your not feeling well.I hope you get better before it gets freezing outside.I would like to build a manual choke also because I know it's just matter of time I've been through 3 .I THINK I saw BD had a resistor on sale today ,but not sure if uterus one you need.

[neo71665]

Thanks, but I'll live.

This is my 3rd one but I replaced the first because it was just old, saved it because as far as I know was still working. The 2nd one I had to replace because I had a nightmare fitting a intake on it. Had to put a spacer on the intake and the valve ended up slamming into the rack because I tried to soften up the rear shocks a bit. Ended up moving the gas tank mounting. Welding it on top on the bar it came on bottom of giving me all kinds of more room. Frankly I don't care about the "racing" intake but imho I like design better vs factory one it replaced. Hindsight I shoulda just milled it down to fit but I was hopped up on pain meds back then. It's been working fine all these months so I aint messed with it.

[neo71665]

Well went out today and the bloody thing cranked right up. I don't know,it was warmer. I checked an old enrichment valve and it worked fine so I swapped it out. I checked the one I pulled off and it worked fine. Fired up my little mill and started machining a manual choke and the end mill snapped. 2 steps forward and 3 back on this thing ever since I got it.

I'm giving up for a few at least it's running for now. We have plans on a ride this weekend and I'm sure it'll act a fool again.

[OLDKID]

As a temporary get-by to get too your ride you can A/ if you have a stock airbox , use your hand over the air intake ( like a choke butterfly ) while somebody hits the start button . Did this for quite a while on one of my Yerfs till I replaced enrichment solenoid & resister , and went to a UNI filter . Or B/ if you have a UNI or similar , pull the filter and use your hand or a spray bottle with gas to get it to start / warm up . Usually after the initial start of the day they'll start up all day long without a choke , etc.

[neo71665]

Yeah I got a redneck intake and a can of ether I plan on throwing in the tool box. Thanks for the help.