can't find an answer then ask here someone may be able to help!!

Is the throttle cable hooked in the slot in the carb slide? Look in the end with the air cleaner off and see if the slide moves when you twist the gas.
 
:-|| moter starts and runs when you pull in the cluch it idles, but when you give it gas it stalls, peddle and it starts right up, give it gas and it stalls
 
Pull the carby apart and give it a thorough clean ,also when the cable is attached to the carby give it a pull when the motor is running ,making sure your clutch is engaged ,if it revs when you pull the cable it's your throttle adjust if it bogs down it means your fuel flow is to high ,best bet is pull the carby apart and check if theirs any dirt in it ,also check the inline filter on the tank ,simply take the fuel line off the carby and turn on the tap and check if you have good fuel flow ,IMHO that may be the issue ,the motor has enough feed to idol but won't allow enough flow when powered

Regards Henshooter
 
im new to this site i been looking for answers on what might be wrong with my 80cc motor it starts up when i let cluch out and idles it seems to wanna rev up when i try to accelerate but it wont accelerate it dies out on me i cleaned the muffler out and carb i checked the floater and spark plug i also let the gas out of tank and it flowed good back into the gas can it ran fine for the first 2 days i had the motor it was riding home and the motor backfired on me and smoke came out from where the spark plug is im trying every thing to get it up and going again but im at a loss and im not a motor person so i realy dont know what im doing plz help
 
Possible problems:
Loose cylinder head nuts.
Blown cylinder head gasket.
Loose spark plug.
Bad spark plug.
Backfire blew out a crankshaft seal.
Bad kill switch caused the backfire.
Bad CDI caused the backfire.
Bad electrical connection between the magneto and CDI caused the backfire and still persists causing a no start situation.
 
hey everyone..! I have a question for all. First, thanks for all your great how to's and help. Couldn't do it without ya'll. So if i changed out my fuel petcock(stock chinese one) with one you get at auto zone in the cheap section, could that cause flooding? I did and i notice that I have a bigger stream coming out of this new petcock. Sounds obvious but would that change your ratio? I should bend the tangs downward to lower the fuel level I am thinking. Right now the bowl is filled up(not to the top but maybe 1/2" lower) but its the same level as its always been with my old petcock. I have a 66cc BB flying horse, stock everything(except spark plug wire and plug ngkb6hs), NT carb set on 2nd notch from top and new gaskets. I torqued head bolts down 120 inch pds. I found that i had a magneto oil seal leaking and just changed that out along with buying a new mag. The motor will fire up fine(which before it struggled with that seal leaking and i think my mag went out right after) but i still can't get the thing to idle. I am bout to go out and change the e clip around and look at the spark plug since its brand new and check color. I still think its flooding itself out but will update soon as i look.. Just wanted another opinion besides my own driving me crazy haha Thanks for your help everyone Oh and Maniac..when you changed out your seals, did you change out both the mag side and crank side(which im assuming is behind the small bevel gear)? I looked at it but couldnt really tell the shape it was in since the one i took off the mag side and it didnt even look damaged but just not properly installed.. thanks
 
If the petcock flows adequately it will not cause any problems.
You stated that your new one flows more that the old one so you are good to go there.
It is the carburetor that controls the air/ fuel ratio, not the petcock.
Now, if there is any dirt or other trash that has been allowed to enter the carburetor (perhaps manufacturing trash left in the new petcock from the factory?) it can easily clog the fuel jet(s) as well as prevent the float valve from closing all the way.

Concerning the NT carburetor specifically, a no idle condition is either a problem with the idle speed screw setting or a massive air leak downstream of the carburetor.
Check the areas where the carburetor attaches to the manifold and where the manifold attaches to the cylinder.
Some folks spray the areas with WD40, carburetor cleaner, or starting fluid.
NEVER EVER use brake cleaner!
Here is why:http://www.brewracingframes.com/id75.htm
I have found that plain ol' water works too.
Spray in short, controlled bursts at different places where the parts come together and listen for a change in the RPM's.
If you do use a flammable spray, be wary of where it is going to. If it gets drawn into the air cleaner it will also get burned in the engine and that too will cause a change in RPM's
 
Thanks GearNut for the info. I think i did the dummy and wasnt thinking when i took the bike out to start. I didn't put on the clutch cover w/gasket. Im gonna troubleshoot that first but was curious if my petcock would alter anything. I took my carb apart starting from the beginning of the gas tank line. After each piece of hose and filter, and on the top section of the carb. the tangs would stop the flow and no leaking there. Looked at the seal underneath the small bevel gear and it looks like its not flush.. can't see any rubber shavings(i put dab of grease on gears and cant tell if there is a leak). The way the mag side seal was im gonna assume this other side wasn't properly sealed either. Im goin outside now... update to come.. Thanks again .bf.
 
OK everyone...I am back with an update-- So I tightened what i had loose( cdi box, clutch cover), put spark plug wire back in, new plug(ngkb8hs) and made sure throttle cable wasnt binding which happened to be one of my original problems. I started pedaling and nothing. Seemed like my clutch was slipping. Disappointingly i shuffled to garage, took the cover off and turned it C.Cwise about 2 notches. Took it back out, started up, died and after 2nd pedal attempt clutch seemed slippy again and wouldnt engage/disengage. Adjusted back a notch and started up fine. Still wouldn't idle but messed with the screw and got it idling and rode back and forth down the street bout 5 times to get it operating temp. (While trying to get it to idle i noticed a leak around the weld on the curved part of the muffler going in to enlarged end. I looked for anything leaking ON it but couldnt find anything else. And it was leaking out the bottom of the muffler slightly) I twisted the throttle and let it go and it returned to idle with no hesitation. My issue now is that it is getting hot in that short amount of time and seems to be a little choppy on power when i accelerate and not original speed at fullish throttle. I pulled the plug after cooldown and its clean but its wet and just a few oil spots(not like my other dark colored insulators on my rich plugs) but nevertheless still wet. Both motors of mine the plugs have been a little wet and i think im flooding it. ON my 3rd tank of gas and running 25 1 the whole time. No carb adjustments done to it yet but bowl level sits a 1/2" below gasket opening and carb is level on bike(before it was leaning towards the motor) Thanks again
 
OH, and I looked at my small gear oil seal also(to rule out the hotness factor since i switched to a colder plug) and it looks like its not flush with the case. Should I have changed that one as well? I am still learning the ins and outs of these 66 cc motors and value all your input since i am beginning to get less frustrated to the point i might actually 'like' working on them..hehe For as the air leak checklist i dont find anything else except maybe my carb throat. But that is gonna get gasketed up today. Thanks and have a good day/night
 
hi im new to this forum nice to meet you all I came here cuz im having problems with my 66/80cc motor on my beach cruiser. it'll start up but best way I can say it is. its like out of gas it'll start up for maybe a min with no power what so ever but sounds like it wants to die. I thought maybe it was the carb so I changed to the stock one hoping it would fix it but no such luck. it'll go for maybe 5-10 feet at best like its idling then it just dies like its not getting any gas. I know its getting gas ive checked the gas line ive even tried using carb cleaner on the old one to see if maybe but now nothing. any ideas what the problem maybe? any would help would be very much appreciated. it only has at best 30 miles on it. it was running perfect the day before. I have no idea what went wrong. the guy I got it from cant really help me. the only people I know that work on these types of things want way to much to work on it almost double what I paid for the motor.
 
I took apart the top end of the motor thinking maybe it was a scratched cylinder or something wrong with the cylinder or piston and everything looks fine I can post pics if that would help.
 
Check your fuel for freshness. Clean the in tank screen (On the fuel shutoff valve)
cdk666
Jangalang, ALL china engines are jetted silly rich from the factory. They ALL leave a wet plug from the factory. Mine needed THREE sizes smaller on the main jet, but all engines are different so tune yours accordingly.
 
maniac57 said:
Check your fuel for freshness. Clean the in tank screen (On the fuel shutoff valve)
cdk666
Jangalang, ALL china engines are jetted silly rich from the factory. They ALL leave a wet plug from the factory. Mine needed THREE sizes smaller on the main jet, but all engines are different so tune yours accordingly.
Click to expand...

true 'dat. Ive run as low as a 61 in a totally stock setup, perfect temp gauge checked.
 
the fuels maybe 2 weeks old at most. checked the filters that was one of the first things I did and still same problem. I did take apart the cylinder and found that one of the 2 rings that go around the piston was broken but that happened after the problem started. I hope putting a new one in will fix it but if it doesn't any other ideas as what the problem might be?
 
Thanks maniac for the reply. I am still having the blubbering and it seems like my base gasket(a harder copper one from juicemoto) keeps leaking. the torque stays the same at 120 inch lbs (i did lap head and cylinder body top n bottom). I had tightened the head studs down(seemed a lil shaky) before and i have only checked and had to retighten slightly once out of four times but it still seems to be the same result. I changed to a ngk b6hs and it runs better but plug is still a tad 'burnt' black but insulator is dark chocolate. I know im still running a lil rich but that wouldnt cause blubbering would it? (gas/oil mix at 25:1 4th gallon...reason is cause i had the seal backwards for all that time and it was running so hot i just left the gas the same). Now, SPEAKING of RINGS my top ring looks 'closed' round the groove while the bottom looks less closed. When i re-installed after lapping it slid over piston after i got em in the grooves lined up. The piston moved freely with no audible noise. Just trying to get to know things better.. Sorry for interupting CDK but as for your problem since its so new only guess i would of had is clogging exhaust or your clutch needs to be adjusted properly? I can only relate personal experience. Maniac, Tom, and many others are better versed to working these problems thanks ya'lldnut
 
Hi Norm,

Couple of questions. First I understand enough on on ac/dc/ ohm's/ current, but some is like spanish ---?
What is the life expectancy of a chinese CDI?
Is it supposed to cop out and hi rpm quickly?

Here's my issue, I have a chines crate motor (cheap), ebay purchase, blew gears in 2nd tank of break in. Ebay seller sends new lower. Sweet, extra parts! Starts, runs for 1 ride then won't start. I do the checks as suggested OHM'S etc. Problem CDI. I order a new one. Run's for 2 miles and craps. My fuel air mix is great.

It seams that you cannot restore a CDI, only get new or build. If a chinese version is purchased again and installed, what can be done to not have it blow on higher RPM? This seams to be the issue. My timing is on and the key on magnito is good.

Finally, I am running racing fuel now and a lower heat plug. It's sweet, but top end still sucks.

To reiterate -
CDI (chinese life expectancy)?
Does this fuel hurt the bike and what should be the running temp?
Quickest fix. I don't know anyone around me RACE CITY USA (nascar country) that is doing this. I turn heads and need this to run. My CDI's seam to crap in 1 or 2 rides on 1/4 to 1/2 throttle! I need a cheap fix, permanent fix for minimal $$ as I am unemployed and just got a job that I use this for transportation

Thanks,
RC Cowboy
 
SHIM SHIM

ok, when i was taking apart my HT engine, I noticed that there were no shim on the behind the mag and the small gear.

and there were two behind the clutch assembly.

should all four places (both sides on the crank and clutch shafts) have a shim.

I have tried to find the exploded diagrams, where they go (#14) but I cant really tell if they should be installed in all four places.

as the diagrams are really bad.
 
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