Posts
5
Joined
12/30/2020
Location
Gaithersburg, MD
US
Hi, I have read through a lot of threads on here about PW50 issues and they have been very helpful.
Bought the bike back in Sept. and it was in pretty good shape, it ran OK but I have never ridden a PW50 so I don't have anything to compare to. Seemed slow but good enough for my 6 year old as her first bike. I put a throttle stop on it at 1/4 throttle.
2 days ago the bike was really low on power and my daughter couldn't get it to move under her. Then it started to cut off and wouldn't idle without the choke on.
Here is what I have done so far:
- checked compression when cold: 130 psi after 10 kicks, seems good according to the threads I have read
- checked plug, see pic, tan in color, throttle stop is set to about 1/4 throttle
- opened up carb and check for plugged jets, check jetting, pilot: 40, main: 70, needle: 3x24 no ability to change clip, everything looked very clean
- checked header pipe for block plate, was not there
- burned exhaust pipe with MAP torch, stuck torch in header opening and let it get red hot, did the same on other end
- unplugged the connector behind number plate, now it starts in "start" or "run"
- new air filter
- cleaned filter at petcock
- fresh gas
I am stumped and my daughter is disappointed she can't ride her bike. Any help is greatly appreciated.
Bought the bike back in Sept. and it was in pretty good shape, it ran OK but I have never ridden a PW50 so I don't have anything to compare to. Seemed slow but good enough for my 6 year old as her first bike. I put a throttle stop on it at 1/4 throttle.
2 days ago the bike was really low on power and my daughter couldn't get it to move under her. Then it started to cut off and wouldn't idle without the choke on.
Here is what I have done so far:
- checked compression when cold: 130 psi after 10 kicks, seems good according to the threads I have read
- checked plug, see pic, tan in color, throttle stop is set to about 1/4 throttle
- opened up carb and check for plugged jets, check jetting, pilot: 40, main: 70, needle: 3x24 no ability to change clip, everything looked very clean
- checked header pipe for block plate, was not there
- burned exhaust pipe with MAP torch, stuck torch in header opening and let it get red hot, did the same on other end
- unplugged the connector behind number plate, now it starts in "start" or "run"
- new air filter
- cleaned filter at petcock
- fresh gas
I am stumped and my daughter is disappointed she can't ride her bike. Any help is greatly appreciated.
The Shop
I was thinking it was some adjustment I got wrong when I put on the throttle cable last week. So that begs the question, why does the throttle cable split and what the heck is it hooked to in the back of the motor?
Edit: oops soopah already answered.
What should I be cleaning with emory cloth?
I will try cleaning electrical connections, cleaning carb with emory clith and seafoam.
If that doesnt work its off to ebay for a carb I go.
If you unplug the connector but the wires are shorted together on the harness side the bike will run as you have it in start mode.
If the choke makes a difference that might be a clue. Are you lean? Is there water in the fuel? Water in the fuel will make it not rev and be very inconsistent revving and then nothing. Broken reed?
You need to narrow down if it's electrical, fuel, or mechanical. Add air by running with the airbox off, add fuel by running with the choke, any changes? Try pulling the plug cap off and just set it on the plug, this will increase your spark, any changes? Lightly blow an air gun in the intake while running, any changes? Remove the plug cap and shove the wire on the plug, any changes? Keep testing and you'll figure it out. We have a tool that goes between the plug and the cap, for testing spark, when it's the governor is stuck in the CDI you can see the spark dissapearing on the tool and it makes for quick diagnostic of a bad CDI.
Thanks again and happy new year.
Pit Row
Must run small inline filter before carb
RC motors fuel filter
All this should be done after the carb has been thoroughly disassembled and cleaned in an ultrasonic tank if you have one. Another thing to do is junk those large block standard tires and put on the Pirreli or Maxxis tires with much more aggressive pattern to save them sliding out so easily. And a top end rebuild if not much compression or resistance on kick lever with your hand. If al that is good, years of trouble free riding.
Good luck and dont push them too hard or be in a hurry to get them on a KTM 50 if they're low on confidence.
I assumed this was a fuel issue with the pilot jet so I removed the carb again....then again....cleaning out the pilot jet and passage but couldn't see any obstructions. I ran the bike with not pipe or air filter and it still wouldn't idle. Took the carb off again and realized I never blew out the air screw passage the first 2 times I cleaned the carb. Removed the screw and blasted it with carb cleaner. Let the bowl drain out and now the bike will idle.
I removed the throttle stop and now the bike runs much better.
I will still preemptively go through the electrical connections and pack with die electric grease but for now all is well.
Thanks for all of your help and suggestions, I am sure this will help me and anyone else searching for answers in the future.
Mine is a 2000 model so I'd say after 20 years and 5 kids the carb has probably run its course.
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