Engine Trouble Engine flooded or totally screwed? Loud noises??? (Pics and video included)

sweersz

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Jul 31, 2011
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Hey guys. First of all, I've searched relentlessly and have not found a solution to my problem so far regarding my 80cc BGF engine.

I am in the break-in period with about 100 miles. I run a 16:1 ratio. I've always notice oil spewing out of where the spark plug fits and dripping out of the exhaust from time to time. Nothing went too wrong until yesterday.

I was full throttle down a hill and all was well. About 2 minutes later, my engine started to struggle and wouldn't respond to the throttle; it just bogged like crazy.

It progressively got worse within a mile's period; it would bog at low speeds and high speeds; I couldn't even go 20mph. When I would try to, it would bog and backfire (would make a loud boom).

I checked the exhaust to see if it was clogged, nope! It was fine. I also swapped carburetors to see if it would run better but there was no change; the carb has nothing to do with this issue.

I have a high performance carb. Did it let too much fuel into the engine? Is my engine flooded? I pulled the plug and head to see what everything looks like and it doesn't look very good (by the way, I have an NGK B6HS plug (.020 gap) and swapped it out after the other one was dirty... now this one is dirty).

See pics...

Spark plug:
http://img822.imageshack.us/img822/9199/dsc08554v.jpg

Head from above:
http://img84.imageshack.us/img84/1179/dsc08552j.jpg

Head from below:
http://img822.imageshack.us/img822/7747/dsc08560b.jpg

Inside engine (doesn't look good):
http://img854.imageshack.us/img854/7624/dsc08551.jpg

Excess oil:
http://img853.imageshack.us/img853/9799/dsc08559t.jpg



Once I put everything together, I fired up the bike and this time there was a loud popping noise almost as if the exhaust is off. I checked the exhaust gasket and it was fine; all of my gaskets are fine. The bike still bogs and doesn't go anywhere. Here is a video to get a better understanding:

http://imageshack.us/clip/my-videos/11/diu.mp4/

I am lost. What should I do? Any help would be MUCH appreciated... thanks!!!
 
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(let's have a look)

Hey guys. First of all, I've searched relentlessly and have not found a solution to my problem so far regarding my 80cc BGF engine.

I am in the break-in period with about 100 miles. I run a 16:1 ratio. I've always notice oil spewing out of where the spark plug fits and dripping out of the exhaust from time to time. Nothing went too wrong until yesterday.

I was full throttle down a hill and all was well. About 2 minutes later, my engine started to struggle and wouldn't respond to the throttle; it just bogged like crazy.

It progressively got worse within a mile's period; it would bog at low speeds and high speeds; I couldn't even go 20mph. When I would try to, it would bog and backfire (would make a loud boom).

I checked the exhaust to see if it was clogged, nope! It was fine. I also swapped carburetors to see if it would run better but there was no change; the carb has nothing to do with this issue.

I have a high performance carb. Did it let too much fuel into the engine? Is my engine flooded? I pulled the plug and head to see what everything looks like and it doesn't look very good (by the way, I have an NGK B6HS plug (.020 gap) and swapped it out after the other one was dirty... now this one is dirty).

See pics...

Spark plug:
http://img822.imageshack.us/img822/9199/dsc08554v.jpg

Head from above:
http://img84.imageshack.us/img84/1179/dsc08552j.jpg

Head from below:
http://img822.imageshack.us/img822/7747/dsc08560b.jpg

Inside engine (doesn't look good):
http://img854.imageshack.us/img854/7624/dsc08551.jpg

Excess oil:
http://img853.imageshack.us/img853/9799/dsc08559t.jpg



Once I put everything together, I fired up the bike and this time there was a loud popping noise almost as if the exhaust is off. I checked the exhaust gasket and it was fine; all of my gaskets are fine. The bike still bogs and doesn't go anywhere. Here is a video to get a better understanding:

http://imageshack.us/clip/my-videos/11/diu.mp4/

I am lost. What should I do? Any help would be MUCH appreciated... thanks!!!
 
Going WOT on a downhill is not good. The fact that it starts up & tries to run tells me not too much is wrong with the engine at this point.

In your video.... the popping I hear, sounds (to me) like your head gasket is leaking. (or blown ? )



ok..... 16:1 is way too much oil. IMHO

try 25:1 for a tank or two. & another fresh spark plug (try gapping at .028 )
 
It almost looks like the top of your piston is partially gone. It does sound like you have a bad head gasket or the bottom of your muffler came off.
 
I would try to clean everything up, if possible.
Inspect the head and exhaust gaskets, replace if need be.
Clean the spark plug really well.

Also, as ddesens stated, your piston doesn't look very good.
Clean it, take a picture, and maybe try to scrape off that black stuff.
Looks just like carbon to me, too much oil, but it may be something worse..
 
Yes the head gasket was leaking...Mill the head and install a new gasket coated with
, on both sides. Some use aluminum spray paint.I coat each side twice.
The piston/spark plug looks like that the carbon was built up due to excessive oil mix. That should scrape off. You didn't mention detonation, so the piston/spark plug should be good, once clean. Trash the junk studs and nuts, go with a grade 8.8, (USS grade 5). Torque the head down to 120 (minimum) to 200 (maximum) INCH POUNDS. I use between 150 and 175. 150 the first build and 175 if I ever have to go into it again. Once I put spray on the gasket, and change hardware, I have NEVER had to remove my head. Been riding since 3/2009
 
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i cant see any sign of leaking on the head...it looks pristine actually. but.

me personally, despise those heads. the only one ive had leaked instantly and never has sealed. always on the plug side. milling only compounds the problem... removes material from an area thats already deficient... they should have cast more material and machined the plug recess into it. instead, compounded with the fact that theres no cooling in that spot, and that aluminium expands proportionally with heat... you get PICT0264.JPG



get yourself a new head gasket and head...with the central plug.

thats just my two cents worth

never had an issue in this area with the good old 48 with a standard head.
 
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You can flip the head making the spark plug heads to the carb. This way the fresh mix will cool the head, the other way there is the heat from the exhaust plus the heat from the plug.
 
You can flip the head making the spark plug heads to the carb. This way the fresh mix will cool the head, the other way there is the heat from the exhaust plus the heat from the plug.

you could do that. id say its the way theyre supposed to be mounted! still doesnt change the fact i got so annoyed with the thing that i melted it down and made an ashtray out of it :)

and then went back to the trusty reliable 48s :D that 66 was a nightmare...a lemon! a frustrating piece of junk! never again!
 
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