50cc engine troubles, need some help...video inside. - Page 6

Amber Lamps · 06-25-2009, 07:06 PM

Quote:

Originally Posted by was92v

Work through one thing at a time. If you skip around to different things it makes it hard to keep everything straight.

Yea I don't say things very well but that's what I was getting at. You need to make sure one thing is "perfect" before moving on to the next problem. Otherwise you can never be sure what the actual problem is.

SteveP · 06-25-2009, 09:35 PM

Quote:

Originally Posted by TIGGER

Yea I don't say things very well but that's what I was getting at. You need to make sure one thing is "perfect" before moving on to the next problem. Otherwise you can never be sure what the actual problem is.

I totally disagree.

One problem can give symptoms in different systems. For example. I had a guy that was 100% sure his cooling system was f'ed. Changed everypart in the cooling system, gauges still read it was overheating. Turned out to be an electrical problem. Just because it's running rough doesn't mean it's the carb.

Amber Lamps · 06-25-2009, 09:41 PM

Quote:

Originally Posted by SteveP

I totally disagree.

One problem can give symptoms in different systems. For example. I had a guy that was 100% sure his cooling system was f'ed. Changed everypart in the cooling system, gauges still read it was overheating. Turned out to be an electrical problem. Just because it's running rough doesn't mean it's the carb.

Ah you're probably right but how will he know it's not the carb until he has it completely cleaned and repaired?

SteveP · 06-25-2009, 09:54 PM

Quote:

Originally Posted by TIGGER

Ah you're probably right but how will he know it's not the carb until he has it completely cleaned and repaired?

Carbs can be kinda touchy if someone doesn't know what they are doing. Just because he thinks it's perfect, doesn't mean it is. Time to get a good manual.

BobTheBiker · 06-25-2009, 10:57 PM

or send one of em to me to service.. I'm real good like with carbs.

Kaneman · 06-25-2009, 11:00 PM

Quote:

Originally Posted by SteveP

Carbs can be kinda touchy if someone doesn't know what they are doing. Just because he thinks it's perfect, doesn't mean it is. Time to get a good manual.

Really? Man it just seems so simple, there are only a few pieces. But I definitely don't know what I'm doing. I should've learned all this a long time ago.

I can tell you that the newer looking carb the float and float valve are two separate pieces, plastic and metal respectively. Its free floating with no spring.

On the older carb its a different set up and the float valve appears to be spring loaded.
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YAMAHA IT250H SPECIFICATIONS

Kaneman · 06-25-2009, 11:02 PM

Quote:

Originally Posted by BobTheBiker

or send one of em to me to service.. I'm real good like with carbs.

No thanks man, part of the reason I got this bike was to finally learn this shit so I can keep my son's dirt bikes running and eventually work on my bikes too.

Unlike my Dad and Grandpa who used to hook my '82 XR80 up to the four wheeler and drag me around in gear until it finally fired up.
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Wendie 99

was92v · 06-26-2009, 12:02 AM

The quickie rule on floats is: With the needle valve in the seat and float installed, turn it upside down and hold the float level. The adjusting tang should just touch the needle without compressing it.
If the tang is pressing on the needle valve, gently bend the tab until it just touches with the float level. If there is a gap when the float is level, bend it the other way until it lightly touches. Just make sure it is not installed upside down before you start bending things...

You might also hold the float under in a cup of water for a few minutes and make sure it doesn't try to fill itself with said liquid. If you see bubbles or hear/feel water in the float you will need one that doesn't leak.

Usually if it is level, it will work fine and you can cross that off the list.

But if you must do it right... the bottom (top when it is upside down) should measure 15.5mm above the gasket surface, and the the pilot air screw should be 1.5 turns out from light bottom. The spark plug should be an NGK C7HS gaped at .028, and the idle speed is 1200RPM.

Particle Man · 06-26-2009, 09:13 AM

You should also learn to read the spark plug coloring to see if the engine is running rich or not...

http://www.rscycles.com/tech_article...park_plugs.htm

the plug is waaay too covered in gunk

Papa_Complex · 06-26-2009, 09:59 AM

Quote:

Originally Posted by Particle Man

You should also learn to read the spark plug coloring to see if the engine is running rich or not...

http://www.rscycles.com/tech_article...park_plugs.htm

the plug is waaay too covered in gunk

Which makes me wonder if it's not blow-by and the rings are shot.

06-26-2009, 09:13 AM	#59
Particle Man Custom User Title Join Date: Nov 2008 Location: Central NY Moto: 2003 SV650S Posts: 14,959	You should also learn to read the spark plug coloring to see if the engine is running rich or not... http://www.rscycles.com/tech_article...park_plugs.htm the plug is waaay too covered in gunk __________________ I'm not "fat." I'm "Enlarged to show texture." Handle every stressful situation like a DOG: If you can't eat it or hump it, pi$$ on it & walk away.

06-25-2009, 10:57 PM	#55
BobTheBiker too much time on my hands Join Date: Jul 2008 Location: the northern district of god damn Moto: 01 ZX6R, looking for more now. Posts: 1,802	or send one of em to me to service.. I'm real good like with carbs.

06-26-2009, 12:02 AM	#58
was92v Nowhere Man Join Date: Nov 2008 Posts: 558	The quickie rule on floats is: With the needle valve in the seat and float installed, turn it upside down and hold the float level. The adjusting tang should just touch the needle without compressing it. If the tang is pressing on the needle valve, gently bend the tab until it just touches with the float level. If there is a gap when the float is level, bend it the other way until it lightly touches. Just make sure it is not installed upside down before you start bending things... You might also hold the float under in a cup of water for a few minutes and make sure it doesn't try to fill itself with said liquid. If you see bubbles or hear/feel water in the float you will need one that doesn't leak. Usually if it is level, it will work fine and you can cross that off the list. But if you must do it right... the bottom (top when it is upside down) should measure 15.5mm above the gasket surface, and the the pilot air screw should be 1.5 turns out from light bottom. The spark plug should be an NGK C7HS gaped at .028, and the idle speed is 1200RPM.