Carb help PW80

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PE175

~SPONSOR~

Jan 18, 2003

68

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• Feb 9, 2004

• #1

I just bought a 1985 PW80 for my son. The bike runs decent enough exept it has a few carb problems. First off I took the carb apart and cleaned it really well. I noticed it is supposed to be oil injected but the previous owner removed the oil tank and cut the cable going to the oil pump. Anyways I mixed some gas (PJ1 Goldfire @ 32:1) and put in a new plug NGK Bp6es. The bike runs good (and did before I touched it) it's just that it won't idle... I mean it will idle for about 20 seconds and just die. I have fiddled with the idle screw and it does nothing. ALSO the bike will not even run unless the air screw is all the way IN. Other than this it's a good bike, I would like to fix this problem though, so if anyone knows anything please help me out? Thanks guys.

 

Last edited: Feb 9, 2004

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biglou

• Feb 10, 2004

• #2

Sounds like it's a little lean. I've seen big bikes do this, where the pilot is too small and the idle screw has little or no effect on keeping it running and they will die without throttle input. Not real familiar with this bike, but a size up on the pilot might help it out.

Just throwing ideas out there...

Moved to the Mini Forum.

 

Vic

***** freak.

LIFETIME SPONSOR

May 5, 2000

4,008

0

• Feb 10, 2004

• #3

With a bike that old, I would suspect a leaking crank seal.

 

gwcrim

~SPONSOR~

Oct 3, 2002

1,881

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• Feb 10, 2004

• #4

Yeah, it's either too rich or too lean. Since someone's already futzed with it, you really can't tell from most folks experience.

What does the plug look like after it dies? Is it wet & smelly? Black or white? Are you sure there are no vacuum leaks? That was the problem on ours. The boot around the carb didnt' seat properly.

 

P

PE175

~SPONSOR~

Jan 18, 2003

68

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• Feb 10, 2004

• Thread starter
• #5

gwcrim said:

Yeah, it's either too rich or too lean. Since someone's already futzed with it, you really can't tell from most folks experience.

What does the plug look like after it dies? Is it wet & smelly? Black or white? Are you sure there are no vacuum leaks? That was the problem on ours. The boot around the carb didnt' seat properly.

Click to expand...

Well the plug is wet, it's also a little black and carbony. I was thinking about leaning up the oil/gas ratio and maybe that would ritchen up the air/fuel. I don't think the carb had ever been opened up, there was prob 1/8 inch of muck and scum in the bottom of the float bowl. But what I don't get is why the air screw has to be in all the way for it to run.

Thanks guys.

 

gwcrim

~SPONSOR~

Oct 3, 2002

1,881

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• Feb 10, 2004

• #6

PE175 said:

But what I don't get is why the air screw has to be in all the way for it to run.

Click to expand...

Carbs are not uniform in their idle mixture screw operation. Some you screw in for lean some you screw out. At the moment, I forget which way the PW80 carb works.

And I sure imagine that the jetting would need redone to compensate for the oil now being mixed with the gas. You'd probably need a bigger jet.

 

J

joereitman

Member

Jul 2, 2003

540

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• Feb 10, 2004

• #7

If I recall the air screw on my son's 03 pw80 is disguised as an idle adjuster screw, and vice versa. Seriously. its weird...

If plug is black/wet/carbony, go leaner. I had to go 1 leaner on needle and fiddle with air screw and idle screw a lot.

 

Jasle

Sponsoring Member

Nov 27, 2001

1,358

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• Feb 13, 2004

• #8

if the air screw is on the side closest to the air filter then going in richens the mixture up. if it is closer to the reeds then going in leans it out. Really it sounds like some type of air leak. Considering the bikes age the crank seals sound most likely but I have seen case halves leak and cause the same symptom. Check your play on the crank bearings. If they move around then its time for a rebuild anyway. It should be fairly inexpensive if you DIY.

 

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yam314

Member

Apr 17, 2001

18

0

• Feb 15, 2004

• #9

Since there was so much crud in the bottom of the bowl, I would suspect that the pilot jet is plugged. Eleminate the cheap fixes first.

 

C

christophe43

Member

Nov 29, 2003

13

0

• Mar 1, 2004

• #10

sounds like the carb still has some trash in it.the pw 80 orig.main is 125 and runs on the rich side-its a common to drop down to a 120 and get rid of the autolube.try out some compressed air on every single hole in the carb and im betting that it will straighten it out. :thumb: