I was having the same issues as quagmire02 on my scooter (intermittently bogging down/losing power at high rpm, not picking back up until I brought the speed/rpm down), but I'd also noticed that I'd had to enrich the fuel/air mix after a week or two of non-use. I thought it may be the carb, so I took it apart and treated it with some carb cleaner.

Anyway, I put the damn thing back together (99% cure I did it correctly), put it on the scooter, and now it won't start. While working on it, I also changed spark plug from a 7 to a 6 (slightly higher temp) and replaced the vac lines in case they were getting hot and collapsing.

I know I put the vac lines together correctly, and I would thing a 6 spark plug wouldn't prevent it from starting up. So I assume it has to be the carb. Do i need to "prime" it first, or do something to fill the bowl with gas? I assumed this would happen on it's own.

Just looking for some suggestions before I get pissed off and take it to get repaired at the shop.

5/26/2010 5:58:12 PM

lol, just load it with starter fluid and try it

5/26/2010 6:15:59 PM

I'm not a gearhead, so I have no idea if that's a joke or serious.

5/26/2010 6:47:07 PM

It's serious. Starter fluid should help.

5/26/2010 7:39:02 PM

Oh ok, thank you guys. While it seems common sense, I should probably ask before I fuck something up. I should just inject the starter fluid into the fuel intake?

5/26/2010 7:58:00 PM

Spray the starter fluid into the air intake (wherever it sucks in air before the air filter). Give it a few second long shot and try to crank it. Sometimes you have to spray while pressing the starter button, but usually it'll run just off the little spray you gave it initially.

If the scooter cranks and runs for a few seconds it means your timing is decent, it's getting air, and it's getting spark. In other words, it's not getting fuel and you need to figure out how you fucked up the carb.

Sometimes if it's getting a little fuel the best thing you can do is crank it on starter fluid and give it some gas while continually spraying the starter fluid to keep it running. That's all it takes sometimes to get it to start pulling fuel through the lines and clear out any blockages. ("Sometimes" is the key word there.)

[Edited on May 26, 2010 at 9:23 PM. Reason : s]

5/26/2010 9:22:00 PM

what kind of motor is it? a 4 stroke or 2? If it has a vacum petcock your best bet is to take the vacum line off and hook a vac to it and let it set for min or two. My guess would be that it just didnt fill the bowl with fuel or your float jet is stuck closed.

5/26/2010 9:47:08 PM

^ 4 stroke, 150cc if that makes a difference. i had actually thought about pulling a vacuum on the vac line to introduce some gas, but I didn't know how much pull. How much should I pull on the line to fill the bowl with gas?

^^ I know I'm full of dumb questions, but there's no problem with spraying starter into the air intake and letting it run through the air filter? Is it that finely aerosolized?

5/26/2010 10:24:40 PM

Yeah man...It's fine. It'll go right through the air filter.

The only time you really have to worry about it is with 2 strokes that use mixed oil and fuel or have oil injection because technically the starter fluid doesn't have oil in it and the top end of the engine wouldn't be lubricated. For a 4 stroke it's fine. Crank it, gas it (lightly; just enough to keep it running), and hope it starts pulling fuel through the carb.

[Edited on May 26, 2010 at 11:06 PM. Reason : l]

5/26/2010 11:05:34 PM

See if your petcock has a "prime" or similar setting. Most motorcycles with vac petcocks have it as a bypass to fill the bowls when necessary, so yours may use the same design.

Also make sure any mixture adjustment screws on the carb are dialed in properly, and that the idle adjustment is set to an acceptable starting point. The first time I tore down and rebuilt an old set of motorcycle carbs there were some issues getting everything tweaked so it would run again, but once I started adjustments from a good baseline, it didn't take too long to tune them.

6/2/2010 2:10:01 PM

All you have to do is open the drain plug on the bottom of the carb and see if there is gas in the bowl(Runs out) Take the tube that runs into the back or the carb from the air filter and choke the carb by putting your hand over the back side of the carb if your hand dont come out soaked in gas you got some shit not right.

6/2/2010 2:41:45 PM

Sorry about not updating this. I managed to get it fixed. It was my idiocy that did it. I'm fairly certain I had put the float on upside down, and when I attached the bowl, it forced the pin closed so no gas was getting in.

I figured it might be something I had done wrong, my pride was just forcing me to hope it wasn't.

^^ I'm in the process of redialing the mixture now. It started out fine but I think it's moving towards the way too rich side. Need to readjust.

6/2/2010 7:15:30 PM

6/2/2010 7:45:04 PM