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PW50 carburetor(?) woes.

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I picked up a 1998 PW50 on Sunday. It ran well with the exception of requiring the choke on to idle. We rode up and down the street that day. Same thing on Monday when I got home from work.

I figured the idling issue was a clogged pilot jet. Seems to be fairly common from the research I did online. So I took the carb off to clean with carb cleaner. I put the bike back together and tried it start it. It was a nightmare to start and when it did, it died when I touched the throttle. It did this a few times.

Today I bought a Moose racing carb rebuild kit. I noticed today that fuel was pouring out of the bowl drain hose. So I thought maybe the float needle was bad. It had a rounded profile compared to the tapered point on the new float needle. Unfortunately the results were the same. Hard to start. Died shortly after it did start and fuel dripping from the hose.

The spark plug is new. So is the air filter. It has spark and compression. The plug looks dry. I checked the reeds. They seem to move freely and the metal reeds seem intact. The gas is fresh. The float floats and nothing seems to be inside it when I shake the float. The restrictor wasn't in the exhaust port/header so that's not an issue. I replaced the start/run/off switch AFTER I was already having trouble. Same with the throttle cable. These needed to be replaced and I ordered them the same day I bought the bike.

I'm stumped. My next step is to buy a Chinese clone carb on eBay. From there it's off to a shop. Any suggestions before I throw more money at the bike? Thanks guys.

Edited by duners99

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Turn down the idle screw. Sometimes if the idle is too high it makes it hard to start.

try giving the carb a hit with the plastic end of a big screwdriver. The float can stick sometimes causing it to flood and pour gas out the overflow.

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Mess with your air screw. On these little carbs it goes a long way in getting them to run right. Is the choke moving freely? Theyre jetted so rich to begin with. I dropped a size down to a 67.5 (i think, maybe 65). Also, the exhaust itself can get plugged up. Restrictor is obvious, but the manifold itself has fiberglass that can saturate with oil over the years and the spark arrestor restricts quite a bit. Id pull the exhaust and see if it fires up. Then add just the expansion chamber. Then just the silencer without the core. That should troubleshoot your exhaust thoroughly.

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Thanks for your suggestions.

I found a combination of issues. Here's what has seemingly fixed the problem:

Took the carb apart again. While the pilot jet was clean (new actually), the little pilot hole in the throat seemed to be filled with crud still. Got that cleaned up with more carb cleaner and compressed air.

I couldn't see any light through the fuel inlet. Turns out that was gummed up too. I used carb cleaner, and a piece of safety wire to poke through. So it was a total lack of fuel keeping it from starting.

Once I got it started it was idling real high. The idle screw had no effect. Turns out the slide/throttle wasn't fully closing. This was due to the new throttle cable. The end of the cable housing wouldn't insert all the way into the brass adjuster on the carb. I tried filing the cable housing end, but that wasn't quite enough. So I removed the locking nut off the adjuster and turned the fitting all the way in. This solved the issue with the non-OE cable.

Now I could start the bike. It would idle, and rev up. But it was really pissing fuel out of the float bowl drain hose. I was stumped at this one. For some reason I decided to spray carb cleaner up the drain hose. A minute later I blew air up the hose by mouth (yikes). Not really sure why or how. But that did it.

The bike is running and idling great. I'm going to keep my fingers crossed that the leaking issue doesn't come back.

I plan to look into the possibility of plugged up exhaust as well. I know the owners manual mentions removing the baffle and cleaning as part of routine maintenance. That's next right after I change the oil in the bottom end.

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Thanks for your suggestions.

I found a combination of issues. Here's what has seemingly fixed the problem:

Took the carb apart again. While the pilot jet was clean (new actually), the little pilot hole in the throat seemed to be filled with crud still. Got that cleaned up with more carb cleaner and compressed air.

I couldn't see any light through the fuel inlet. Turns out that was gummed up too. I used carb cleaner, and a piece of safety wire to poke through. So it was a total lack of fuel keeping it from starting.

Once I got it started it was idling real high. The idle screw had no effect. Turns out the slide/throttle wasn't fully closing. This was due to the new throttle cable. The end of the cable housing wouldn't insert all the way into the brass adjuster on the carb. I tried filing the cable housing end, but that wasn't quite enough. So I removed the locking nut off the adjuster and turned the fitting all the way in. This solved the issue with the non-OE cable.

Now I could start the bike. It would idle, and rev up. But it was really pissing fuel out of the float bowl drain hose. I was stumped at this one. For some reason I decided to spray carb cleaner up the drain hose. A minute later I blew air up the hose by mouth (yikes). Not really sure why or how. But that did it.

The bike is running and idling great. I'm going to keep my fingers crossed that the leaking issue doesn't come back.

I plan to look into the possibility of plugged up exhaust as well. I know the owners manual mentions removing the baffle and cleaning as part of routine maintenance. That's next right after I change the oil in the bottom end.

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