50cc 4 stroke Bravo Soleil will not start By heff (Read 1,836 times)

[heff]

Need some advice:  history is unknown, purchased used, did not run.

I have spark, verified by grounding it out to the cylinder head. New NGK gapped at.026. 
I have Fuel, new Keihn carb, fuel lines.
Fresh oil
Fresh high octane gas (tank was drained)

Kicks over just fine, just won't start. I've sprayed starting fluid into the carb; still won't fire up. I have not been able to do a compression check; waiting for some adapters to show up. 

I'm getting ready to pull the cylinder off. Is there anything else that can be causing it not to fire? 

Any help/suggestions is greatly appreciated. 

[Alleyoop]

Do you have the AIR FILTER on the carb?

HAVE YOU ADJUSTED THE VALVES if not set them both to .003 inchs. If the exhaust valve is not sealing been left a little open then not enough compression.

To check if you have Compression us the Finger trick. Take the plug out and stick your finger nice and snug in there and HOLD THE THROTTLE wide open and crank it IF it pushs your finger off the hole it has enough compression to start and run. If you just feel some pressure then not enough compression.

Also before you even do this CRANK IT trying to start and then when you take the plug out to do the compression test LOOK at the plug. YOU just cranked it it some so if it was getting fuel and no FIRING then plug will be WET(SPARK PLUG NOT FIRING) IF DRY(NO FUEL is being sucked in).
Alleyoop

[heff]

Update:
Fuel is getting to the carb; pulses out when connected to the intake manifold. When the vac line from the pecock is hooked up to a small vacuum pump, it will drain out (good flow). 

The battery was low, and still popped my finger off the hole. 

To me the plug wasn't wet.  I'm going to wait for the battery to charge up some more, and see what the plug is doing.

i have a brand new carb and auto-enricher on it. I just slapped it on, figuring I'd adjust the air/fuel after I got it running. 

If the fuel is not getting to the spark plug; which seems like the case. Where do I start?  How can I verify the new carb is good?

**I've had the stock air filter on/off.  

[Bashan]

Follow the path of the gas. You know it's getting to the carb...right? So if it's not getting to the plug what does the gas need to pass through to get to the plug? The float valve is next in line. You're going to have to pull the carb and check the float. I know it's a new carb but weirder things have happened.

[heff]

Update:

Compression test = 90 psi
Adjusted the valves to .004 ( they were barely gapped open)
Compression test again = 92 psi

I'm in the middle of swapping another motor, however it's only at 120psi.

So, I plan to buy a bbk (100cc conversion). I've been looking on amazon and ebay. Any that I should stay away from? What do I absolutely need? Most come with the kit and a full gasket kit. I imagine I need to rejet. I'm finding stock replacement top-end for about the same price as a bbk, so might as well go bigger as long as I'm not missing something.

Thanks

[jvino]

That 90 psi might not be enough to get it running from what some guys have said on hear from the past seems kind of low. 120 should do the trick that's pretty handy you have a spare engine.

[jvino]

to the sight bud alley or bashan are better more noledgable people to ask questions to. There experts.

[Bashan]

120 should start but it's pretty anemic. You're going to want to get that up to 150+. To do that whatever kit you put on will need to include cylinder, piston, rings, head with valves, and gaskets. That's what I would do but you could probably get by with less.