Engine not turning over

[xventox]

My 03 vento was having problems with it's air/fuel ratio and wasn't performing when throttle was fully open. I started to adjust the mixture while doing some maintenance and now the engine won't turn over.

I was checking the drive belt that has some wear on it as well so I don't know if I've screwed up the timing or if that's possible.

I've done the main fuel/air mix from leanest to richest with no luck and also adjusted the idle with no production.

Is it possible to screw up timing because I feel like it's firing at the wrong time now since I'm not getting it to turn over no matter what the fuel mix.
Carb is clean, gas flows, good spark, good battery, dry air filter, spark plug in snug, and I'm all out of ideas.

Suggestions??

[earlwb]

I am not sure by what you mean "not turning over".
Does this mean that when you push the starter button or kick start it that the engine itself is not turning over, but is frozen or stuck?
Or do you mean it is not starting and running?
Does the starter just go clumk and nothing happens? Or are you getting the whrrr, whrrr, whrrr sound as the engine turns but doesn't start and run or fire up?

I suspect you accidentally knocked something loose when you were adjusting the air mixture screw. Most likely a vaccuum line is cracked or broken loose. Check all the vaccum lines and wires and stuff in that area to see if something came loose on you.

[leo]

you can't get "a good spark" when the engine doesn't turn over.

[indy50]

Do ypu mean that the engine wont start? Even with the timing not correct the engine should "turn over". It"d be pretty hard to #@*% up the timing by inspecting your belt, you may have a carb issue,would need more details.

[xventox]

By not turn over I basically mean the engine won't catch and start. It makes the whirring noise like it wants to go but never does. It's not a clicking noise or anything like that as if the battery or starter selenoid was bad.
I've checked all the carb hoses, made sure the vacuum would pull gas, and can't see anything wrong with the carb at all other than something most likely wrong with the mixture. I am assuming that even if the mix was a little off it would at least fire for a little bit.

Is it possible to mess up the timing at all? I was handling the belt (without pulling off any of the covers holding it in) when considering pulling it off so it may have been shifted but like I said, I didn't take any of the assembly off.

[swampsniper]

Got to have some kind of common language around here ;D
"Won't turn over" means that nothing moves when you try to start the engine. "Won't start" means the crankshaft rotates but the engine will not run on it's own.
Why am I even bothering to say this? ;D I just feel grouchy this evening!

[bob]

Have you tried leaving your hand off the throttle and letting the enricher do its job?
Bob

[scooterollie]

Don't see how you could possibly do anything to the timing just by checking the belt. Even if you removed and replaced it, the CVT drive has nothing to do with engine timing and are in no way connected.

If the engine "cranks" when you press the starter button, it is turning over. I think what you really mean is that the engine will not fire and run.

Some good advice - don't mess with the idle adjustment when the engine is not running. There is no purpose to doing that. Idle speed adjustment is only necessary when the engine is running normally but needs to be increased or decreased slightly. Usually only requires very slight turns to the screw.

Turn the mixture screw in until it seats. Don't crank in in hard or with a lot of force, only until you feel it seat. Then turn the screw counter-clockwise (out) 1 1/2 turns. That is the usual starting point and the scoot, if everything else is OK, should start. Since you have already fiddled with the idle speed, you may have to hold the throttle open slightly. If it does start, adjust the idle speed screw until the idle is reasonable. When you attempt to adjust the air/fuel mixture screw, the engine should be fully warmed up and only make small adjustments to the screw - 1/8 to 1/4 turn, max, in or out. Start with one direction and see what happens. If you turn it in some and the engine begins to stumble and die, return the adjustment to the 1 1/2 position. Now turn it out and see what the engine does. After some experimentation, you should be able to find the "sweet spot" where it runs best. Readjust the idle speed.

If you can't get the scoot to fire and run no matter what, something else is wrong.

[xventox]

Thanks for all the advice and next time I'll make sure to be more specific in my thread topic.

I've tried the mix screw from all the way in to all the way out with no luck so I've obviously screwed something else up in the process. I'm going to check the wiring diagram and all of that and hopefully diagnose this thing.

Thanks for all the advice, much appreciated.

[leo]

xventox said:

By not turn over I basically mean the engine won't catch and start. It makes the whirring noise like it wants to go but never does.

you say "like it wants to", this implies the starter turns the engine pretty fast. if that is the case then twist the throttle to about half way when trying to start. as soon as the motor "wants to" let off the starter button while giving it about half throttle. you gotta give it some gas, you can't use the starter then twist the throttle, you gotta use them both at the same time.

caution!:
starter motors work by drawing excess current, it's wise to count to 10 between attempts at starting. after 3 attempts count to 30 or 40. this will keep you from burning up your starter.

my 50cc is a real pain to start when the temp is below 40 degrees.
i gotta put a 10 amp charger on it to produce a hot enough spark

[bob]

Have you tried spraying starter fluid or gas into the carb while cranking it?

[leo]

bob said:

Have you tried spraying starter fluid or gas into the carb while cranking it?

not good advice for two strokes because it (starter fluid) has no oil in it.

side note to my post above:
if your motor does start do not rev it while cold. give it enough gas to keep it running but that's all until it's warm. i usually start mine then finish putting on my gear while it warms up. this isn't really necessary when it's warm out.
when you do get on it to ride, take it easy on the gas for the first 10 to 15 minutes.

[bob]

leo said:

bob said:

Have you tried spraying starter fluid or gas into the carb while cranking it?

not good advice for two strokes because it (starter fluid) has no oil in it.

side note to my post above:
if your motor does start do not rev it while cold. give it enough gas to keep it running but that's all until it's warm. i usually start mine then finish putting on my gear while it warms up. this isn't really necessary when it's warm out.
when you do get on it to ride, take it easy on the gas for the first 10 to 15 minutes.

Sorry, didn't know it was a two stroke.

[leo]

bob said:

Sorry, didn't know it was a two stroke.

i don't know that it is.
i'm just saying starter fluid isn't good for two strokes because it doesn't have any cylinder lube.
if it is a two stroke then they could mix some oil with the gas they use and then spray that into the carb with any spray bottle.
be careful with flames, sparks, and hot surfaces.
i once burned a good riding lawnmower to a crisp using gasoline to start it. all i could do was step back and watch the poor thing burn.

[bob]

A friend of mine power washed his John Deere tractor. He went out to one of his fields to cut some hay and it burned to a crisp. He got off of it and just watched it burn. He said it went up quick. He sold it to a salvage company who came out and towed it away. It was an electrical fire and he didn't have a fire extinguisher on the tractor. Now if you go near Livingston Montana, just about every tractor has a fire extinguisher.

[leo]

bob said:

He said it went up quick.

once the fuel line melts it's all over.
in my case i disconnected the line to run some gas into the carb.
i must not have gotten it connected tight enough, and it just went.
good advice about the extinguisher.

[swampsniper]

Good quality starter fluid will have some lube in it.

[xventox]

I wanted to thank ya'll again, I got the scooter up and running this morning. I had flooded the engine, which knowing the impatient person I am is not a surprise. And since I'm so impatient I hadn't given it the time to air out which I wanted to make sure I did before I moved on to any starter fluid attempts so I left it alone and open last night and she fired like a dream this morning.

At least now if I do have carb problems I've taken that thing out and learned all about it so there's always some positives.

Thank you all again.