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I have a moped and it will not run even though its ran before

i have a 1987 (i belive) Trac Olympic moped and i dont know why it will not run. it has ran before and now it wont. i have spark, i have the fuel going to the carb and filling the bowl, and i have gas and the key is turned. iv also replased the battery and it still wont run. it is a kickstart only moped so its not electrical in that regard. i need help.

How did you test for spark?

@wentwest This may be in your territory .

i put the spark plug it the holder (i forget what its called) and grounded it on the block and tryed to start it and it showed spark

Was it a fat blue spark or orange?

it is a blue spark

Ok, my guess would be the carburetor is clogged with varnish from old gas. Of if you can,get a second person to spray auto starting fluid into the air intake while you try and kick start it. If it gives an indication of trying to run, you’ll need to clean and rebuild the carb.

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Concur with old_mopar above, I had several small-engine 2 cycle dirt motorcycles as a teenager, and if they didn’t start and spark was evident during cranking, and the carb’s fuel bowl was full, almost always a carburetor clog of some kind. It was generally only a 15 minutes job to unclog it, not a big deal. Usually I could fix it with a can of carb cleaner spray, the carb still attached to the engine. Make sure the air cleaner is in good condition btw.

That’s how mine were configured, kick-start w/magneto. The batteries on all of them were always dead, but it didn’t matter at all, just push the kick-starter, the magneto would provide juice for the spark, and away you’d go. The only purpose for the battery as far as I could tell was to be able to turn on the lights or honk the horn with the engine off.

iv looked at the carb pretty good and the float moves and it dosent seem to be cloged but i dont have starter fulid at the moment to try and i cant pour a tiny bit of gas in it ether because of where the air intake is located

read above

On my bikes there were passages that needed to be forcefully sprayed out. Either by pressurized air, or pressurized carb cleaner. I doubt pouring gasoline on the carb would have worked. It’s been so long ago I can’t recall exactly what I did, but I do remember it didn’t take much time. I seem to recall removing the float chamber to access the fluid paths to spray them out. Sorry can’t be of more help OP. Frustrating when you bike won’t start up like it should. Carbon/oil-bridged spark plug electrodes were another common for non-starts on my bikes, but I presume you’ve already checked that. That fact that the float/inlet valve moves freely isn’t the issue. The clog is almost certainly elsewhere.

I always had trouble with the spark plug fouling so wouldn’t start for anything. About an hour job to pull the plug, clean it, and put it back together. But if you already tested the plug that is in there, yeah, bad fuel, dirty carb, clogged air cleaner.

I’ve got nothing much to add. It’s always the same story, fuel and spark. If you have spark, then it’s fuel. You have to go to a car parts store and buy starting fluid (ether) and squirt some into the intake. If you can’t squirt it directly into the carb, then try squirting it into the intake for the air filter. Not a lot, but some, then kick it a bunch. If it so much as pops, you know the carb is clogged.

First, I have to say I agree there is probably a little goo in the carb. That said…

It’s been 5-1/2 decades since I rode my Sears-Allstate (Puch [Austria]) moped with 2-speed, twist grip shifter, manual transmission. It had a regular motorcycle type clutch control.

After the moped, I survived owning seven or eight motorcycles (road & dirt). The last one, a 1977 Honda CB 750K has been sitting in the back of my garage for 32 years when I quit riding.

I’m sure mopeds have changed a little since then, but does this bike have a manual clutch or is it automatic?

Often times a motorbike/motorcycle that won’t start (has fuel, compression, spark) can be started by running with it and popping the clutch (usually in a gear higher than first).

Don’t try this at home… (unless you are very coordinated or have experience), but on some bikes the back wheel will skid when the clutch is released (even in a higher gear) and one (coordinated person) running with the bike, must hop on (side-saddle or regular riding position) and bounce down on the seat while releasing the clutch. This procedure is worth a hundred kicks of a starter.

I’ve seen dirt bikes tip over in a river and submerge. After taking out the spark plug (sometimes inverting the bike) and kick-starting the water out of the cylinder and replacing the plug, the bike won’t run, no matter how many attempts are made.

However, towing it (make sure the rope is wrapped around the center of the handle-bars and trapped with a hand for quick release) with another bike and popping the clutch, they fire up and run after a short distance.

These new-fangled mopeds probably don’t offer these options, but I thought I’d throw it out there.
CSA
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Does it have a fuel valve and/or an engine cutoff switch? Did you check those?

How old is the gas?

Fuel valves sure do plug up, so one way to check for fuel is to open the screw valve at the bottom of the carb and see what comes out. Drain it into a white plastic cup and you can also see what dirt there is in the carb bowl. If there’s fuel in the carb, it’s getting past the fuel valve (petcock).

On every bike I’ve ever owned, if the cutoff switch is OFF, there won’t be a spark at the plug.

There are many things that can cause a 2 stroke engine not to run. Damaged reed valve, damaged main seals, carbon clogged exhaust port or muffler, air leak on intake tube, etc…

A bike like that, even if it doesn’t run, is worth something to someone. The SOHC CB 750 has a following, and I’m betting if you listed it on eBay, someone would buy it and lovingly restore it. I wish I had the time and money for a project like that, because Honda’s CB 750 changed the motorcycle industry by pairing an inline four cylinder engine with a front disc brake, inventing what would become the dominant racing bike layout. That bike is a reliable workhorse, which is why there are still so many around. Also, manufacturing of the CB 750 peaked in 1978.

What you describe shouldn’t be that dangerous on something as small as a moped. Yes, push-starting a motorcycle can be a jolting experience, especially on a large displacement engine with a lot of torque, but it should be pretty easy to get it moving without towing it, just by pushing it with your legs while you’re sitting on it. I’ve push-started two different 750cc motorcycles that way when I had to.

Well, I guess I’ll find out some day. It’s low miles, nice shape, and shiny black (factory chrome fenders & 4 chrome pipes/mufflers if memory serves me from 1500 miles… heavy son-of-a-gun). I kick the starter once in a while and it would go if I put a battery in and some fresh gas. A little longer running back and forth to the condo and we’ll be thinking about dumping our house on the lake and the new occupants will probably want that bike out of the garage.

My brother-in-law has wanted it and my son would probably take it, but no way. If anybody I’m acquainted with ever got hurt or killed on it I’d be the bad guy. I won’t give or sell anything potentially dangerous (guns, motorcycles, etcetera) to anybody I know.
CSA
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