OP
@stevewall avatar
UTC

Enthusiast
'05 PX200, '69 Rally180, '09 Triumph Scrambler
Joined: UTC
Posts: 95
Location: New Zealand
 
Enthusiast
@stevewall avatar
'05 PX200, '69 Rally180, '09 Triumph Scrambler
Joined: UTC
Posts: 95
Location: New Zealand
UTC quote
Merry Christmas helpful scoot folks,

I have 2005 PX200. It starts and runs fine for the first 5 minutes or so and then start to miss badly. It doesn't stall out and will still idle OK after this but anything past about 1/2 throttle it starts to miss and becomes unrideable over 40 -50 kms/hr.
I have changed the CDI ( new, not known good one), first trip out I thought it was fixed as it went for about 10 minutes before starting to miss again. The plug looks OK, and I have changed it. I checked the resistance across of the red, white and green wires pairs and they are within limits.

any helpful tips on troubleshooting very welcome.

Cheers,
Steve
UTC

Veni, Vidi, Posti
Joined: UTC
Posts: 7067
Location: Tega Cay, SC
 
Veni, Vidi, Posti
Joined: UTC
Posts: 7067
Location: Tega Cay, SC
UTC quote
You changed the spark plug, so start from there and work backwards - cap, wire, etc... good luck.
UTC

nothing at all
Joined: UTC
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Location: westla
 
nothing at all
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The px has a black pick up on the stator thats known to go bad.

Ive changed 2on px 150 bikes.

You can follow the schematic and test those wires from stator.
@joshzingzing avatar
UTC

Veni, Vidi, Posti
px200 cutdown,px180,px150. Puch SR. Puch scooterette
Joined: UTC
Posts: 5109
Location: west aus
 
Veni, Vidi, Posti
@joshzingzing avatar
px200 cutdown,px180,px150. Puch SR. Puch scooterette
Joined: UTC
Posts: 5109
Location: west aus
UTC quote
jimmyb865 wrote:
The px has a black pick up on the stator thats known to go bad.

Ive changed 2on px 150 bikes.

You can follow the schematic and test those wires from stator.
yes ^^^^
@rob_hodge avatar
UTC

Molto Verboso
Joined: UTC
Posts: 1924
Location: Seattle
 
Molto Verboso
@rob_hodge avatar
Joined: UTC
Posts: 1924
Location: Seattle
UTC quote
remove wires from CDI.
measure ohms from green to white and red to white.

one should be 110 and the other should be 480, give or take about 10%

if they aren't. yo unwed a new stator, or at least stator component.
OP
@stevewall avatar
UTC

Enthusiast
'05 PX200, '69 Rally180, '09 Triumph Scrambler
Joined: UTC
Posts: 95
Location: New Zealand
 
Enthusiast
@stevewall avatar
'05 PX200, '69 Rally180, '09 Triumph Scrambler
Joined: UTC
Posts: 95
Location: New Zealand
UTC quote
Thanks for the tips. I am back home now and did some further troubleshooting today.

I replaced the plug cap and HT Lead and tried a known good CDI.
red / white wire is 120 ohms which is good. Green to white is 538 ohms so right on the limit from the numbers I've seen.

The scoot will start OK and idles ( a bit rough but doesn't stall) but misses as soon as revs get over about mid range. Does this sound like a pick up? If that had gone i would have thought I have starting problems too.

I pulled the stator and had a good look and all the connections look good as good as new, all clean and intact. I wiggled the wires around while checking the resistance to check for broken wires or loose connections, that was all fine too.
I checked the timing with a light.

I forgot to mention in my first post all this happened post full engine rebuild, the scoot was new to me in a non-running condition, but everything is now new or checked. The engine sounds to be running OK mechanically and I have checked seals for leaks, nothing.
It feels like a miss caused by bad spark but maybe it is fuel related?

Any more ideas of what to check?

Cheers,
Steve
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nothing at all
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Location: westla
 
nothing at all
Joined: UTC
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Location: westla
UTC quote
May sound stupidly obvious but make sure all your grounds are clean and secure.

You stator plate is one ground so maybe pull your flywheel and besure you have no false connections/or loose wires/or wires with wear that maybe grounding. The cdi sometimes has a extra ground wire, be sure that is secure for the heck of it.

It can be a haunting issue if not done........I know.
@trumpyscooter avatar
UTC

Molto Verboso
Black 2007 PX200, Dark green 1986 PX225 Pinasco, "1972"(yeah rite) Tangerine px200, several TRIUMPH TIGRESS SCOOTERS
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Location: New Zealand
 
Molto Verboso
@trumpyscooter avatar
Black 2007 PX200, Dark green 1986 PX225 Pinasco, "1972"(yeah rite) Tangerine px200, several TRIUMPH TIGRESS SCOOTERS
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Posts: 1082
Location: New Zealand
UTC quote
When you took the stator off did you notice the wires where it was passing through the stator? Nothing frayed through fretting against the stator body? and youre sure there arent any cracks in those wires that may expand when warm?

Ok

Once it refuses to idle have you taken a spark plug and hooked it up and given it a kick to see if a strong spark still exists when warm?

Clutching at straws now... check torqued head and carb? what about compression test when cold and then warm?

And blown out main jet?
Timing on the money?
plug gapped correctly?

what about your HT lead? Pushed down into the coil?

Just trying to help
@vader19 avatar
UTC

Mr. Clean
P,SUPER,V90, 50 Special
Joined: UTC
Posts: 10205
Location: This is't my locker!
 
Mr. Clean
@vader19 avatar
P,SUPER,V90, 50 Special
Joined: UTC
Posts: 10205
Location: This is't my locker!
UTC quote
If it's at mid rev and over I assume you're riding... are you sure it's not fuel related? Have you checked our tap, fuel lines and filter, jets etc...
Cheers
@jamesjohn avatar
UTC

Ossessionato
1970 Vespa Rally 180
Joined: UTC
Posts: 4145
Location: Denton Tx.
 
Ossessionato
@jamesjohn avatar
1970 Vespa Rally 180
Joined: UTC
Posts: 4145
Location: Denton Tx.
UTC quote
I would change the gas since it is easy, quick, and cheap.
@cazshie avatar
UTC

Hooked
2003 PX200
Joined: UTC
Posts: 409
Location: Perth, Scotland
 
Hooked
@cazshie avatar
2003 PX200
Joined: UTC
Posts: 409
Location: Perth, Scotland
UTC quote
What do you mean by "missing"?

I had an issue pulling away from standing, where it would almost cut out, which was simply a mixture issue.
OP
@stevewall avatar
UTC

Enthusiast
'05 PX200, '69 Rally180, '09 Triumph Scrambler
Joined: UTC
Posts: 95
Location: New Zealand
 
Enthusiast
@stevewall avatar
'05 PX200, '69 Rally180, '09 Triumph Scrambler
Joined: UTC
Posts: 95
Location: New Zealand
UTC quote
Problem solved . It was the pick up after all.
I swapped in a stator from a mates PX and it went fine so today I replaced the pick up on my stator and popped it back in and she's at beauty once again.

thanks for the tips.

Cheers,
Steve
@joshzingzing avatar
UTC

Veni, Vidi, Posti
px200 cutdown,px180,px150. Puch SR. Puch scooterette
Joined: UTC
Posts: 5109
Location: west aus
 
Veni, Vidi, Posti
@joshzingzing avatar
px200 cutdown,px180,px150. Puch SR. Puch scooterette
Joined: UTC
Posts: 5109
Location: west aus
UTC quote
good





they do that and then just stop and wont start at all





was the black box rubbing on the flywheel at all ?
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nothing at all
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Location: westla
 
nothing at all
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Location: westla
UTC quote
stevewall wrote:
Problem solved . It was the pick up after all.
Cool
@pdxjim avatar
UTC

Molto Verboso
2005 PX150 In a Part-time Relationship with a 2-Stroke Vespa Since 2007
Joined: UTC
Posts: 1867
 
Molto Verboso
@pdxjim avatar
2005 PX150 In a Part-time Relationship with a 2-Stroke Vespa Since 2007
Joined: UTC
Posts: 1867
UTC quote
Quote:
was the black box rubbing on the flywheel at all ?
I second that question. I had the same thing happen to me several years ago to the factory installed one. At first I worried that the crank or bearings had been spinning the flywheel off-center, but that didn't turn out to be the case. The original factory pickup had simply been rubbing all along and eventually crapped out after a few thousand miles.
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