Carb clogging issue... Clean or replace?

[lunatuck]

I did all I could to prevent this issue on my Tao Tao.  I started it every couple of weeks over the winter but it seems like the carb still gummed up.  I even ran it a week ago and it started up just fine, but when I tried to take it for a ride, I couldn't get it started and disassembled the whole carb and gave it thorough cleaning.  I reinstalled it the other day, replaced the pilot jet because I couldn't get the inside of the jet cleaned out.  I put it back together and it it started almost immediately.  I did the same thing all over again and after first start and letting it cool down, it wouldn't start.

Yesterday, I ran it for about 20 minutes and the tried to readjust the fuel mix because even though I used a larger jet, it was idling like it was lean.  It got dark and I gave up.  I tried to start it again yesterday and it wouldn't start even with starter fluid. 

I'm thinking there is something in the inside of the carb that my cleaner just cant get out.  I know the carb cleaner I had wouldn't clean the pilot jet.  I had to replace it. 

So, this carb is only $30.  I've spent 4 days working on it.  If I just buy a replacement will the replacement get clogged as well?  The gas is from last year, but I can't figure out where the clogs are coming from.  The carb had some crystals in the bowl, but the carb cleaner took care of them instantly. 

I helped my friend get his other Chinese scooter started after years of not running, and I never struggled this much. 

I I replace it, will I have the same issue?

[FrankenMech]

When you replace the carb you will have to re-tune all the jets.

[lunatuck]

Apr 29, 2021 11:51:31 GMT -5 FrankenMech said:

When you replace the carb you will have to re-tune all the jets.

I was thinking about buying the exact same carb and just using the same jets after giving them a good cleaning.  What I'm concerned about is that this carb has gunk hidden within that'll just keep clogging up jets and I'll keep having to take it off and on to clean.  I may try cleaning the old one one more time, if not I'll buy the second as a replacement. 

[df41590]

You can try putting the carb in a 50/50 mix of fresh gas and Seafoam, and make a diy ultrasonic cleaner www.youtube.com/watch?v=R1DtY2VwSyY. Also be a good idea to blow out/replace the fuel line and replace the inline filter if equipped, check the fuel tank side of the petcock to make sure the screen didn't come off, and clean out the tank.

[lunatuck]

I ordered a new carb. Something odd is going on. I have spark, compression and fuel. If I can get it started it runs fine. I even replaced the choke with an old one I had lying around.

I spent way too much time on this. I couldn’t even get it to run today. Very frustrating.

[bullybike]

Its a tao tao so simply roll the whole thing out to the dumpster and replace it with the newest latest version that has wifi bluetooth smartscooter only 699 and a 3 month warranty!

Ps everyone on insta thinks you are lame beacuse your model is so 2018 and everyone knows that in the 21st century nothing lasts more than 3 weeks

[bullybike]

Also for sale Samsung smart washer get rid of that 30 year Amana that still functions perfectly and upgrade to a washer with 16 televisions and Ai. Only slightly leaks water will secretly report your foul language to Authoritys and can sing cute toons when your laundry is done being partially cleaned.
Ecosmart low water! 6 month warranty!

*Consumers are constantly demanding more and more and more features at the same price as thier old model so we simply cut costs everyhwere so you can have those superCOOL 16 TVs in your washer so we had Indonesian primary "school" children do all the soldering on the 211 control modules in this thing. We also now make all the gears out of partially recycled American water bottles.

Replacement parts only available from An authoritarianized repair dealer

Also please regularly change your passwords from 1111 for your super smart washer, refrigerator, range, coffee maker, toaster, thermostat, and fingernail trimmers,
or they could simply be hacked by Russian babies and then rise up and destroy the internet.
Please DO THIS REGULARLY or aremegeddon may result.

[bullybike]

P.S
Why Don't we have Chinese Automobiles in America?
GM already owns majority stakes in all the parts stores.

[GrumpyUnk]

When you had things apart, could you see light through the pilot jet? If not, it is likely plugged. If plugged a single strand of wire from a wire brush may be used to poke the gunk out of the center of the pilot. It is the most common problem with these carbs.
That said, does the 'probe' from the choke/byvalve stick out when cold? It should be retracted when cold, and extend when hot. If extended, there is no cold enrichment. Definitly VERY hard to start when cold if the byvalve is dysfunctional.
Initial setting of the hard idle(screw on the throttle shaft arm) can be too high, which makes it harder to start when cold. You want the throttle to be barely opened when at idle. Otherwise, you are into the 'intermediate' speed portion of the carb settings, which makes idle unstable and hard to start. Idle jet, if mucked with, should be ~2 turns out from seated fully(do NOT tighten hard, just gently closed). The byvalve port/jet in the side of the float bowl should be checked. If you have an accelerator pump, it should squirt a jot of fuel directly down the throat of the carb when the throttle is moved open. If no squirt, check the mechanism and diaphragm, along with the little holes involved.
tom

[lunatuck]

May 1, 2021 11:17:22 GMT -5 GrumpyUnk said:

When you had things apart, could you see light through the pilot jet? If not, it is likely plugged. If plugged a single strand of wire from a wire brush may be used to poke the gunk out of the center of the pilot. It is the most common problem with these carbs.
That said, does the 'probe' from the choke/byvalve stick out when cold? It should be retracted when cold, and extend when hot. If extended, there is no cold enrichment. Definitly VERY hard to start when cold if the byvalve is dysfunctional.
Initial setting of the hard idle(screw on the throttle shaft arm) can be too high, which makes it harder to start when cold. You want the throttle to be barely opened when at idle. Otherwise, you are into the 'intermediate' speed portion of the carb settings, which makes idle unstable and hard to start. Idle jet, if mucked with, should be ~2 turns out from seated fully(do NOT tighten hard, just gently closed). The byvalve port/jet in the side of the float bowl should be checked. If you have an accelerator pump, it should squirt a jot of fuel directly down the throat of the carb when the throttle is moved open. If no squirt, check the mechanism and diaphragm, along with the little holes involved.
tom

I brought the pilot to work with me so I could work on cleaning it out. It did have a clog, but I put a larger pilot in and turned the fuel screw in a turn to compensate. I’m hoping to use this jet, but I believe there is some tough to remove clog in it. I can see light through it, but its not perfectly round. Even torching it and using wire didn’t get it all out.

Everything else you suggested seemed to check out fine. The two things I’m unsure of are the choke and whether its fully extended or not, but it looked the same as my backup which worked when I put it away.

It is possible I have the idle opened up too much. I will test that.

Today’s plan is to fully replace the gas and if that doesn’t work, replace the carb. It should show up later today.

[lunatuck]

Replaced the carb and added new gas and it started right up.

I think whatever clogged the pilot jet is hidden within some unreachable part of the carb. Maybe in the choke port or maybe the idle circuit. Not sure, but at least its starting now.

[\\-olf]

My view is these carbs are cheap for a reason, $30 for a brand new one is too cheap, the machining and all is hit or miss, the jets are cheap enough to throw away and buy a kit that has a range of sizes, I dont bother cleaning this stuff out, way too many tiny passages and holes to get 100% clean. Same with the enricher, it's electric, they also fail, make sure it has power to it and works.

I'd like to get a Keihn carb but there's so many FAKES and knockoffs out there now you almost can't find a genuine one, it would be a big improvement if one can find a GENUINE Keihn carb

[scooter7878]

Buy a new carb and new jets in whatever size u want and a manual fuel petcock remove the vacuum fuel petcock put the manual in and new carb and be done. When the scoots gonna sit more than 5 days or so shut manual valve off and run scoot till it shuts off this will run the carb dry and prevent this to a extent. Also if available use ethonal free fuel which is much better all around and to be honest I get like 10 more miles from a tank and it runs way better on e free fuel at least mine does but non ethanol fuel does not clog fuel systems as much