No combustion in engine/won't start

GoldenMotor.com

Targan

New Member
Jun 22, 2013
56
0
0
Scottsdale
So this problem has happened gradually. A couple of days ago my bike started losing power (only slightly). I wasn't able to go top speed anymore, but I just ignored it thinking I could ride the issue away. The next day I left for work as usual, rode about halfway (4 miles) and it just started bogging and losing all sorts of power (ontop of what power it already lost). It got so bad that I just had to turn it off and pedal to work in a 100 and some degree weather. It would still start though, but violently jerk. The whole power loss thing happened gradually though, not all of a sudden. When I got my bike home I did the basics (i am no mechanic FYI). I pulled the head off for the first time ever too. There is some really dry dirt like stuff caked to the top of the piston head, is this normal? My spark plug was also almost completely black. I am using a 32-1 mix, but this spark plug was used for the break in period too. I cleaned it off and tested it for spark. It sparked just fine. My kill switch isn't sticking and I even disconnected it. I tried running it again and now there's not even combustion, not a single pop or bang. I guess the only thing I haven't checked for is if fuel is getting to the engine? How do I go about doing that? Also to explain how the bike ran before completely dying: it felt exactly like a time awhile back when I had way too much oil in the gas and it was bogging down. I've heard stories about it being the clutch or something? I am not mechanically savvy so any answers need to be dumbed down lol. Thank you for any help.
 

Targan

New Member
Jun 22, 2013
56
0
0
Scottsdale
Forgot to mention when I opened the head up the top of the piston was bone dry. The walls were oily however. Does this mean no gas is getting in? I may have just figured it out. I'm still going to wait for an opinion before moving on. I have that damn grubee stock carb with the plastic tubes coming out, and I don't want to mess with it if I don't have too.
 

maniac57

Old, Fat, and still faster than you
Oct 8, 2011
4,484
22
0
memphis Tn
Pull the fuel petcock and clean the screen inside. Use a inline fuel filter as well. You can check fuel flow by pulling the line and seeing if fuel drains from the tank. If not, you found it!
 

Targan

New Member
Jun 22, 2013
56
0
0
Scottsdale
Yeah the gas flows all the way to the gas overflow. When I unscrew the CNS carb overflow screw gas comes pouring out. I just dont know how to check if gas is getting to the engine.
 

maniac57

Old, Fat, and still faster than you
Oct 8, 2011
4,484
22
0
memphis Tn
If you have fuel in the bowl but none in the cylinder, I'd look for a clogged jet or passage inside the carb.
Personally, I hate the cns so I'd chuck it and fit a rt or speed carb for simplicity and ease of tuning, but thats just me.
Search carb cleaning threads for tips on your cns.
 

Targan

New Member
Jun 22, 2013
56
0
0
Scottsdale
I'm so dumb, I forgot about about the search function lol. I forgot this site is chalk full of tutorials. Thanks for the help :)
 

Targan

New Member
Jun 22, 2013
56
0
0
Scottsdale
I hate to re-vamp this thread but the issue happened again. Long story short to fix the problem I had in this thread I just bought an NT Carb and installed it (it fixed it but i don't know why, I was planning on getting this carb anyways, not to just fix the issue). I also bought a new spark plug and inline fuel filter. Ran amazingly until today. The motor out of no-where just start bogging and slightly jerking. It won't even idle. At one point it just wouldn't even combust and when I kept pedaling i heard a loud sound like when you open a bottle of soda. A spurt sound. I drained fuel from the carb and it started again but still bogged. I am at work and this bike is my only way home. Is this an oil issue? I mix 32:1 but dont use the best oil (those $1 8oz bottles from walmart, 2-stroke oil). I was wondering if I just added more gas without oil to the tank if it would fix it. My bike was rained on for a bit 3 days ago as well and I've only ridden it for 5 minutes since then. Could there be water in the carb/engine?
 

maniac57

Old, Fat, and still faster than you
Oct 8, 2011
4,484
22
0
memphis Tn
Water will collect at the bottom of the tank so it's easy to disconnect the fuel line and let it drain until only gas comes out. (if this is the problem)
Easy to check.
 

Targan

New Member
Jun 22, 2013
56
0
0
Scottsdale
How does water get in the gas tank? I feel like it would take a huge downpour to get any water inside those holes on the gas cap. But thanks for the advice, I'll be sure to check it out. Still open to other thoughts though.
 

bluegoatwoods

Active Member
Jul 29, 2012
1,581
6
38
Central Illinois
This is little more than a shot in the dark....but.....

Why don't you open up your exhaust and see if it's plugged up with dirty oily garbage?

Your oily spark plug and rather oil heavy fuel mix suggest that this might be a possibility.

Good luck.
 

Targan

New Member
Jun 22, 2013
56
0
0
Scottsdale
This is little more than a shot in the dark....but.....

Why don't you open up your exhaust and see if it's plugged up with dirty oily garbage?

Your oily spark plug and rather oil heavy fuel mix suggest that this might be a possibility.

Good luck.
I'm not too "mechanically inclined" so I'm worried I might mess something up further. But you do have a point. I'll check it out and see when I get home if I can open it up. What should I use to cleasn it out? Carb or brake cleaner or something?
 

sboricic123

Member
Apr 15, 2013
172
3
18
Bailieboro, Ontario
This is little more than a shot in the dark....but.....

Why don't you open up your exhaust and see if it's plugged up with dirty oily garbage?

Your oily spark plug and rather oil heavy fuel mix suggest that this might be a possibility.

Good luck.
I agree with bluegoatwoods. I had a similar problem with my 66cc Flying Horse and it turned out to be the exhaust all plugged up.
 

crassius

Well-Known Member
Sep 30, 2012
4,032
158
63
USA
just loosen the two nuts at the top of the muffler so there is a bit of gap - start the engine and see how it runs - don't run it long that way or you may destroy the gasket of worst case when the piston gets hot a bit of cold air may hit it and instantly fatigue the metal
 

Targan

New Member
Jun 22, 2013
56
0
0
Scottsdale
just loosen the two nuts at the top of the muffler so there is a bit of gap - start the engine and see how it runs - don't run it long that way or you may destroy the gasket of worst case when the piston gets hot a bit of cold air may hit it and instantly fatigue the metal
Smart idea! Seriously thanks I wouldn't have thought of that. Makes sense, if it's clogged it'll run better with the exaughst being vented like that.
 

Targan

New Member
Jun 22, 2013
56
0
0
Scottsdale
Ok... I have cleaned out the muffler, tested the bike without a muffler (no difference, still bogs), ran straight gasoline through the bike for a couple of minutes then added a fresh 32:1 mix into the tank, new spark plug... I am at my wits end now. Nothing has worked! Could it possibly be the magneto dying from being in the rain? And on top of all this my new dirtbike blew a hole in it's header pipe. I am starting to hate anything with 2 wheels now! :-||