engine wont stay running

GoldenMotor.com

kr632

Member
Apr 13, 2009
77
0
6
buffalo
hello, i have a 2 stroke engine from thats dax i want to say its a 68cc. i have been riding it and it has been working fine untill the other day when i staretd her up and she would struggle to pull my weight but she would idle(i wouldnt call it very well). when i let the clutch out she will go(sometimes) to around 13-17 mph. but she will struggle to maintain speed and will back fire if i open the throttle up and will shut down if i dont catch it and keep her idling. the guy across the street said there was too much oil in the engine and thats what is causing the problem(he didnt look at anythin just the sound of it). he said to empty the gas out and mix it correct. i did this and she started to run almost at 100% but there is/was still a little studder sometimes. then after riding her a couple more times through out the next couple days she does this again. so this time i take the spark plug out and it is a dark brown color, i put the spark plug in tight and tighten down any loose bolts. change the gas and oil again and peddaled around for a while trying to start her, nothing. the next day i get home from work and wanted to fix her, so i tried to start her once more before i take her apart. and she started right up and worked good for the last couple days. now it wont start and it doesnt sound like it is getting spark all the time, it will spark once in a while. what could be the problem
 

biken stins

New Member
Jul 11, 2008
156
0
0
If your still useing the spark plug from the kit you might want to replace it.
The color sounds good but that don't mean the plug itself is.
 

2door

Moderator
Staff member
Sep 15, 2008
16,302
175
63
Littleton, Colorado
What ratio of oil to gasoline are you using? The suggestion to replace the plug is sound advice. Many before you have had premature spark plug failures using the kit supplied plug. Look for a NGK B6HS plug available at auto parts stores. Check the high voltage lead (spark plug wire) at the plug boot and the CDI. It simply screws into those two parts. If the engine was running good then it is a good bet that there is no serious problems and the trouble can be traced to poor ignition or a fuel problem. You said it ran good after changing the fuel at your neighbor's advice. That could indicate that your fuel petcock filter could be partially plugged and when you changed fuel you cleaned it but it is now plugged again. Try some of these suggestions and get back to us with the results.
Tom
 

Venice Motor Bikes

Custom Builder / Dealer/Los Angeles
Mar 20, 2008
7,266
1,797
113
Los Angeles, CA.
Are you pouring the oil straight into the gas tank? or mixing it in a separate container & shaking it well first??
Also... Mix it at 24:1 for the break in!
 

kr632

Member
Apr 13, 2009
77
0
6
buffalo
for the first gallon of gas for the break in i had the oil mix at 20:1 after that its at 32:1.i have went thru about 4-5 gallons(at 32:1) after the first gallon. the problem started at the 3rd gallon when my friend mixed it. i have since emptied all the gas out and put fresh properly measured gas/oil in it. after doing this i started her up and she struggled for a min. but slowly gained speed and after 10 mins of slow riding and idling i had her up to 20 but u can feel that it wants to go faster but something is holding it back. this was yesterday. i am waiting to get paid so i can change the spark plug, CDI,fuel filter and fuel line. it seems do do this in cycles, one day it works fine and then a day or two later she doesnt want to go and then its fine again.
 

Venice Motor Bikes

Custom Builder / Dealer/Los Angeles
Mar 20, 2008
7,266
1,797
113
Los Angeles, CA.
There's no need to change the CDI.
Take off the float bowl from the carb & dump out that gas, (There could be oil sitting at the bottom of the bowl) & change the gas filters & plug. That should do it.

& from now on, DON'T LET ANYONE ELSE MIX YOUR GAS! ;)
 

Cabinfever1977

New Member
Mar 23, 2009
2,288
1
0
Upstate,NY
I did that, but i shut the fuel petcock off first then shook the whole bike, it worked but i don't reccomend anyone do it like that. Mix your oil and gas in a separate container.
 

dsebastian

New Member
Aug 23, 2015
5
0
0
Scottsburg, In
Thanks everybody, I really appreciate the replies and apologize for the late response. I had an issue with my password but as soon as I get home I will take a pic and post it. Also, it is a 2 stroke motor from china.
 

crassius

Well-Known Member
Sep 30, 2012
4,032
158
63
USA
Can you lock the clutch and keep it running with throttle? if so, do that while turning idle screw on carb clockwise until it will run without throttle.
 

crassius

Well-Known Member
Sep 30, 2012
4,032
158
63
USA
nope, you need a gauge - most auto parts stores will loan you one for free - over 100 pounds it is OK, around 60 pounds a gasket is leaking (or ring is broken), at 25 pounds a seal is bad
 
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