Bike will not start. New (1 month)

[nik]

Hello. This is Nik again..

I have some problems that i was hoping someone here could help me with.

First I have had problems "starting" this bike since i got it, however problems.. they only have gotten worse since the start.

(i have replaced spark plug, spark boot and fuel petcock.)

I put the choke on, make sure the fuel valve is on, go to a hill... start to pedal downhill.. waiting for a start... waiting.. pedaling.. nothing.

I try it two more times at least.. then i start to play with the choke... still no start. not even a spark!

I take out the plug and place it back into the spark boot. Then i drive it with the clutch out and i see sparks! Yes, im getting sparks.

So, I take the carborator apart, make sure its good and clean,, yes, and make the needle sit at the "3rd" position" .. and i tried 2nd and 1st also.

I have not been able to start the bike much at all. and I keep wondering if the engine is being flooded. I look at the sparkplug and it is sometimes a little wet.. but not too much.. (i think)

I should mention that gas/oil seems to want to come out of my exhaust pipe here and there.. drip drip. I took off the baffle and noticed a little pool of fuel in the baffle "well" which i had to pour out (about a 1/4 shot glass worth) (havent take off the baffle in a couple weeks.. so that was built up)

I think that is because of all the start attempts. eventually the engine began to flood..

I decided to see if the magneto was bad, i put a new magneto in the engine (bike sat for about 2 days before start attempt)...

and 1st attempt to start with new magneto .. and it started. right up!

sweeeeet. 10 pedals and boom..so i let it idle for about a minute.. i go to take off.. and i stall it out~ doh!

so.. i then go to restart asap.. and nope. not starting again.

that was about 4 days ago. It hasnt started since. And i have gone over all of the trouble shooting..

Today i went and bought cork/rubber gasket material from the auto store 6$. I exacto knifed a gasket to replace the muffler engine gasket just in case it was causing an air leak. ... still not starting.

I read a ton of posts on motorized bike forum trying to troubleshoot...

I found a post saying that spark plug gap should be at .15 (mine was at .25-
.30) so i adjusted it smaller.. hoping

still not starting.

I put the choke on (up).. stand a the top of a hill.
get on, pedal and let out the clutch.

it will not start.

What could be causing this? (compression, fuel, air, spark?)

Ive read a post saying give full throttle at start.. I have tried that also, and no start. I usually do not use throttle when i try to start.. (is that bad)

I think I was flooding ( even though i do not squeeze throttle when trying to start .. so i dont flood .. )) so i would pull out plug, walk bike around a minute with clutch out to burn excess fuel and put plug back in.. just to see if that helped. not really.

in fact nothing seems to make this bike start.

I dont think anything is wrong with it.. the piston moves fine, the head bolts are tightened. the chain is tightened. the clutch cable lets out fine (allows the piston to move and spark to ignite while in boot)

The carb has been looked at a lot. no leeks i can "see" all connections are tight... fine carb.

The bike seemed to start well the first week or two. and I only rode it around rather gently.. i never really "opened it" up at all. (WOT) maybe 6 miles total.. no more than a mile in a day.

I have run out of things to look at! Could it be the CDI? ( not big suspect)
Could it be an Air Leak? ( not a big suspect) all things are tight!
Could it be a magneto problem.. (magneto less than week old!, it started first time i tried to run with new magneto, after that .. would not start)

Could it be kill switch.. ( its not even hooked up. ) no
Could the clutch cable be slipping? .. ( the clutch engaged when let out and piston pumps) no.

Could it be the Chain? ( nope. )
Could it be the spark plug? ( new plug and new spark boot. )

is it the CDI? i have no idea! seems fine during spark test

is it the choke? ( i use full choke to start, then slowly start trying more open choke..each attempt that dont start engine.. no luck)

is the fuel old? ( its not very old maybe a couple weeks , but has only been in the fuel tank itself for about a week)

The mixture is fine at least 20-1 or the 6 oz (2stroke) of oil per gallon

Does anyone think they know?? I am so close to just losing my mind here that i dont know what to do.

I really have tried to be patient.. When things go wrong i try to work them out.. but this is so frustrating because i am so stumped! I am not a mechanic and this is my first engine (see my intro post) but i never anticipated this much of a problem.. Please help me if you can! I want to ride. my life sucks now. ps (long story short! lol)

 

[Skyliner70cc]

If its one of those kits (dax style) that has a crappy kill switch, disconnect it.

What is your plug gap?

Old fuel?

Did you physically blow out the main jet. It could be clogged even if the carb looks nice and clean.

Do you have compression?

There are so many variables. To rule out fuel and carb, remove air filter assembly/box and squirt some starting fluid into it while pedalling. 1 to 2 squirts should be sufficient to tell if it is the carb not getting fuel. You should try this with the fuel valve off.

Did you check to see that fuel is flowing freely in your fuel line? Remove line at carb and open valve, fuel should trickle.

Buy lowest octane fuel you can buy, mix in fresh oil and try again to start.

Recheck all wiring.

 

[Demosthenese]

Wow, that's an unfortunate list of tries to not get it started again. Hope we can help!

Since it worked that one time and didn't make any catastrophic noises when it stopped, all evidence points to your individual parts working fine. It sounds to me like an electrical problem, because a lot of the time engine problems that don't seem to have a cause are electrical. There could be a lose wire somewhere that is causing this. Even if you ran it forward and saw the spark, could be when you adjusted it an all ready weak wire got moved ever so slightly. In my experience, the connection between the plug cap and the plug is quite resilient; on my bike the plastic peice that goes out of the cdi and fits over the spark plug is all broken, but it stays on anyway by itself and still works fine, so i wouldn't think it was that.

Could be a fuel problem? Maybe the float in your carb is stuck and not allowing fuel to the intake, or maybe the hole the needle fits in is blocked by something, a small piece of dirt could screw thing up in there.

If you figure it out and discover your engine is working, just hard to start, i would recommend grabbing some regular lighter fluid and spraying a little onto the air intake before starting it up. It always works for me in really cold weather.

 

[Skyliner70cc]

Pull the head and make sure you have two piston rings. Make sure they aren't cracked. I actually got an engine once with only 1 ring.

 

[BSA]

What happens when you dump the clutch can you hear the engine actually turn over, or does it just grind to a halt and become hard to pedal? I've had that problem also, the engine would be flooded. Just try starting without the choke, still not working? keep on trying trust me it will work eventually. When you can hear it turn over, keep on pedelling and turn the throttle to maximum, yes maximum. BTW how long are you depressing the tickler for. Should be apprx 2 seconds.

BSA

 

[nik]

Thanks guys, all good advice..

I have a spark gap of .15-.20.. i have tried up to .35

The fuel is not brand new, maybe a couple weeks but im sure it is still flamable!

I know that fuel can get "stale" i havent got new stuff just yet.

I got my engine and bought 2 gallons of gas.. i have not even used 1 and 1/2 yet.

I have compression ( i think) .. when the plug is out i drive with clutch out and hold my hand down over the hole.. and i can feel the air pooofing out and i feel the piston going up and down..

today when i installed the new exhaust gaskets on the muffler.. i looked inside at the piston and moved it up and down (moving the bike back and forth) the piston looked nice.. rings looked ok.. from my limited view through the exhaust hole.. i think things indie there are ok.. no symptoms of problems with piston..

When i attempt to start with "choke on" the bike goes slower down the hill than when the choke is open/off. so i assume i have good compression. when i take the clutch

The Jet in the carb is open, i made sure it was not clogged with dirt" i checked the whole carb assembly .. fuel bowl too. all clean.. I made sure that the needle was correct.. and i placed it into the 3rd position.

Should i use choke up and pedal down a big hill to start?
should i squeeze the throttle in order to "prime" the engine or should i allow the air to bring fuel into the cylinder?

I havent been able to get the correct conditions for the engine to fire which is strange.

I also think its some kind of electrical problem. But i have not a clue as to how! I just got a new magneto about 4 days ago.. installed it and the bike fired right up .. one time.. now it wont.

i have blue to blue
black to black
and white to nothing.

i have not installled kill switch.

.... any further thoughts?

 

[nik]

bsa.. i have just tried to start the engine again.. with no luck.

I tried with choke on.. went down hill let out clutch (going good speed) i know the piston is moving inside because it does when the spark plug is out. so i assume it is pumping with the plug inside and im pedalling down the hill. I tapped the tickler button a couple times quickly.. (im sure there is fuel in the bowl, so i dont know if i need to press it really) then i tried to pump the throttle a little bit as i went down the hill. ( i didnt hold it down the whole time)

I checked the plug again and its gap is around.15-.20 and it was not "wet" (sign of flooding)

also,,, i checked the sparkplug as i drove.. i pulled it out and watched it spark good next to the engine block a couple times (spark good)

Im not sure why this wont fire up!

how much fuel needs to be in the cylinder when it fires .. (small amount?)
how much air needs to be in the cylinder when it fires up? (smaller amount??)

Thanks again for all you guys help.. i have to get this bike running this weekend or i will ghost ride it off a bridge!

 

[Demosthenese]

it's funny because it's just like my secret embarassing story lol.

When i first installed my engine, i installed the kill switch too. Spent two days trying to start the thing. Couldn't figure it out, racked my brains, tested all the electrical with a wire testing kit, the works. And then i realized. The kill switch isn't there too KILL the engine by pressing it. It's there to kill the engine if it's NOT pressed. And also, apparently to keep the engine OFF if NOT pressed lol. I had no prior experience with kill switches and i just misunderstood the concept i guess, even when wiring it into the circuit and knowing which way the wires went lol.

So i held it down and she fired first time. It was a mixed moment of satisfaction, acheivment and realization that i was an idiot, but a happy one .

Not saying that's your problem, just my bike shared every single symptom with yours, ie being in perfect working condition and not working. Electrical is still my best guess, but that magneto thing, firing just once, that's weird. Worst comes to worst, grab a wire tester and open the magneto housing and test the blue and black wires for continuity from source. You might want to walk it forward while looking into the magneto housing, just to check for sparks that would indicate shorts. If you are plugging the wires together with those metal clips that come on the ends, you could try stripping the wires yourself and twisting them together with electrical connector caps, or you could even solder them. Even just electrical tape temporarily.

i have found that the key to starting my 2 stroke is starting at an appropriate speed, pedaling through the first couple turn overs of the engine, and starting it in WOT. Don't just pop the clutch on a hill or at speed, pedal the engine into starting. And don't pop the clutch till you have some comfortable momentum, and then hold the throttle open full till it catches, no way that can flood the engine (unless you did it for a long time i guess).
To start it in the cold, i throw the choke on hard and i squirt lighter fluid into the air intake. This makes it start on the first or second pedal almost every time, in -10 C.

edit- ok so it's not electrical... so it must be either fuel delivery, or compression. If you say your carb is clean and working, then it may be that you have no compression on your engine, causing no fuel to be sucked in?. This could be because of a blown head gasket, a crack, a leak, or it just might not be tight enough. I'd say check your head bolts, but it says up top you all ready have. You can take the head off and look at the gasket to see if it's obviously cracked, like if it's scortched on one side or something. It's usually? a thin piece of metal that fits the studs and goes between the head and the block.

I would be careful with your engine; if you're trying to start it over and over with no luck, and no fuel is getting in, then that means no oil is getting into the cylinder either, so it may not be lubricated very well. Don't know how much damage you could do, just occured to me because normally in a leaking engine, you'd see were it blew because oil and gas would leak from there.

gl

 

[nik]

thanks.. Demosthenese

you have me wondering.. i do not have the kill switch installed.. perhaps it wont start without it???

I will wire the kill switch in and give it a try... fingers crossed.. and ill have to try with button pressed in once too.. thanks and stay tuned!

 

[misteright1_99]

bsa.. i have just tried to start the engine again.. with no luck.

I tried with choke on.. went down hill let out clutch (going good speed) i know the piston is moving inside because it does when the spark plug is out. so i assume it is pumping with the plug inside and im pedalling down the hill.



I would check the clutch adjustment. What I have read on here the clutch might be holding when no compression, but when plug is in and there is compression, the engine might not be turning over. I also was under the misconception of the "kill switch" I thought you pushed it to "ground out" the electrical system to kill spark to plug. I did not know you have to hold it to keep engine running.