Heard a pop, now it doesn't work

[amyvomit]

hey guys, again, i've spent hours trying to find the verbage to fix my problem. I was riding my bike and i heard a pop then it just quit working. when i try to get it started the engine sorta runs but i cant give it gas and then i pull in the clutch and it stalls. does anyone know what that pop was and how i can fix it? i took the spark plug out and looked at it and it looks fine.

i have an 80cc raw engine.

thanks much

 

[Pablo]

Do you still have full compression?

 

[Bikeguy Joe]

Check for spark. Look closely at the engine to see if you blew a gasket (brown funk dripping or oozing).

It sounds like your engine is turning, just not firing.

 

[Norman]

is it a newly built bike if so sounds like the pop you heard might be the head gasket leaking or it blew a hole in the gasket
check the head bolts if they are loose then it might pay to try to re torque them with a torque wrench
or pull off the head and see if you have a hole in the head gasket.

 

[amyvomit]

thanks all for the replies.

if i do pull off the head to check the headgasket, i know that i should replace it anyway. what do i use as a headgasket or where do i buy one?

thanks again

 

[a_dam]

If your first name is Amy, that's one appealing username!

 

[amyvomit]

uh...thanks?

 

[BarelyAWake]

thanks all for the replies.

if i do pull off the head to check the headgasket, i know that i should replace it anyway. what do i use as a headgasket or where do i buy one?

thanks again

Most kits come with a replacement head gasket, dig around for somethin' that looks like this;

- but if not, give ThatsDax a call, gaskets are cheap enough (like $5 or so)

BTW - you prolly know this, but the "80cc" is around 66cc actually, so you'll hafta take some (easy) measurements, you'll find 'em on the product page here: ENGINE_KIT_PARTS_PAGE_2

 

[Pablo]

thanks all for the replies.

if i do pull off the head to check the headgasket, i know that i should replace it anyway. what do i use as a headgasket or where do i buy one?

thanks again

67/"80"cc head gasket Check the stud size first.

 

[Bikeguy Joe]

Although, just to stir the pot and get back OT, I have never heard a head gasket "pop" when it went bad.

Was this "pop" like a crack sound? Where did you hear it from? Did it just go "pop" then the engine froze, or what happened?
Or, did it go "pop pop pop pop pop " until you stopped?

Have you started checking the easy regular stuff before you pull the head off?
Check for spark.
Check for positive fuel flow.
Can you pedal the bike with the clutch in?

More details please, we'll get you running again.

 

[amyvomit]

It was just one single pop which i guess could also me construed as a crack???? i honestly dont know if i'd ever know the difference.


then then i just couldn't give it gas anymore. when i try to get it started, the motor runs slow only while i'm pedaling but the second i pull the clutch in, it goes dead. then i can pop the clutch, pedal and and it will run a bit but never really engage.

how do i check for a spark?
how do i check for positive fuel flow?
and i can NOT pedal the bike with the clutch in and the motor running at all. it kills every time.

 

[OCCstingray]

I think it is a lack of spark. To check for spark, remove the sparkplug from the head leaving it connected to the sparkplug wire. Then turn the engine over by pedaling with the clutch handle released and look at the gap at the bottom of the spark plug. If you see a spark then obviously you have spark and that is not the problem. My sparkplug wire came loose one time and as I was pedaling the bike to get it started, the engine would not fire up, but just was turning over and would not run with clutch pulled in. When I looked down, I realized that the wire was not connected fully.

 

[Bikeguy Joe]

Check for fuel at the carb by pressing the primer button until you see/feel/smell fuel.

 

[Kevlarr]

Also check the connections on the blue and black wires going to the CDI. When mine came loose the engine would backfire and generally run like crap. It's possible a connector came apart and the "pop" you heard was a backfire.

 

[2door]

I think it is a lack of spark. To check for spark, remove the sparkplug from the head leaving it connected to the sparkplug wire. Then turn the engine over by pedaling with the clutch handle released and look at the gap at the bottom of the spark plug. If you see a spark then obviously you have spark and that is not the problem. My sparkplug wire came loose one time and as I was pedaling the bike to get it started, the engine would not fire up, but just was turning over and would not run with clutch pulled in. When I looked down, I realized that the wire was not connected fully.

Amy,
You'll need to hold the plug tight against the cylinder head. This will complete the electrical circuit. Simply holding the plug in your hand while pedaling or pushing the bike will not give you a spark. Hold the spark plug against the head, leave the clutch engaged then walk the bike forward at a good pace. Look for a spark at the tip or the electrodes of the plug.
Tom

 

[Kevlarr]

Amy,
Simply holding the plug in your hand while pedaling or pushing the bike will not give you a spark.
Tom

It won't give you a spark but you may still find out if you have spark.

 

[Motor Boys]

I had it happen 2 times last week the poping sound both times it was my rings.
Thanks

 

[Motor Boys]

different engines on 2 of my bikes, found a broken ring on each of them.

replaced both sets easy fix, and I was off to the races.
Thanks

 

[a_dam]

I had it happen 2 times last week the poping sound both times it was my rings

different engines on 2 of my bikes, found a broken ring on each of them

Elaborate?

 

[Bikeguy Joe]

Two rings broke in two weeks?

I'd be all over that like a hobo on a ham sandwich.

There is a major problem somewhere if you have that kind of failure rate!