50cc engine troubles, need some help...video inside. - Page 2

Kaneman · 06-23-2009, 02:26 PM

I picked up this 84 Z50R in a trade with a guy. Bike seems to be in decent shape, he told me it wasn't running and he hadn't ridden it in 2 years or so. He had like 5 50's in his shop. (For those of you that remember Shugga from SBN and Stuntlife.com, that's who I got it from)

Anyway, so I got it, turned the gas on and cranked it for a bit....low and behold I got it to fire up. Rode it up and down the street. It was running but not very well, didn't have power under full throttle and had poor throttle response.

So, shop manual in hand I took the following steps:

1) Changed the oil only to find that the oil in it was brand new.
2) Bought a new air filter
3) Drained all the old gas and filled it with fresh 87
4) Removed the carb, sprayed and soaked with Carb cleaner

After all that it ran more poorly, as seen in this video. This is the first time it was started today and fired right up after a couple of kicks on choke:

So I pulled the spark plug, which appears to be getting good spark. It looked pretty good, but just in case I replaced it with a new one.
Here's the original:

That didn't make any difference. Right now the jet needle is on the factory default second notch from the top. However I have tried 1 through 4 without any varied result:

This video was taken after the spark plug change:

Here are some more pics of the carb:

So, any suggestions on what to try next? This is really my first shot at anything besides basic maintenance. I should have all the tools I need to work on this lil' 50 motor and I have the shop manual. Any advice or suggestions are greatly appreciated, I know there's some real experienced folks here. I've got all day so if you need some pics or more video for a good diagnosis let me know.
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Anal Plug

06-23-2009, 02:26 PM	#1
Kaneman AMA Supersport Join Date: Nov 2008 Location: Odessa, TX Moto: 2000 Honda CBR1100XX Blackbird Posts: 4,931	50cc engine troubles, need some help...video inside. I picked up this 84 Z50R in a trade with a guy. Bike seems to be in decent shape, he told me it wasn't running and he hadn't ridden it in 2 years or so. He had like 5 50's in his shop. (For those of you that remember Shugga from SBN and Stuntlife.com, that's who I got it from) Anyway, so I got it, turned the gas on and cranked it for a bit....low and behold I got it to fire up. Rode it up and down the street. It was running but not very well, didn't have power under full throttle and had poor throttle response. So, shop manual in hand I took the following steps: 1) Changed the oil only to find that the oil in it was brand new. 2) Bought a new air filter 3) Drained all the old gas and filled it with fresh 87 4) Removed the carb, sprayed and soaked with Carb cleaner After all that it ran more poorly, as seen in this video. This is the first time it was started today and fired right up after a couple of kicks on choke: So I pulled the spark plug, which appears to be getting good spark. It looked pretty good, but just in case I replaced it with a new one. Here's the original: That didn't make any difference. Right now the jet needle is on the factory default second notch from the top. However I have tried 1 through 4 without any varied result: This video was taken after the spark plug change: Here are some more pics of the carb: So, any suggestions on what to try next? This is really my first shot at anything besides basic maintenance. I should have all the tools I need to work on this lil' 50 motor and I have the shop manual. Any advice or suggestions are greatly appreciated, I know there's some real experienced folks here. I've got all day so if you need some pics or more video for a good diagnosis let me know. ________ Anal Plug Last edited by Kaneman; 05-09-2011 at 08:07 PM..