Peugeot speedfight 2 50cc ac not running again!

Hi all,

Its been a while, but I've not really had many problems until a few weeks ago.

For some reason, she stopped running again, so, I stripped and rebuilt the carb completely, replaced the coil, replaced the reeds, charged the battery and replaced the filter.

Spent a week or so tweeking the carb so that it was running good. It wouldn't start without a shot of easy start. Carb tuned and engine sounding like it's running good.

Went out today to see if she would start on her own. To my surprise, she started on the first touch of the starter! High revs while choke was on, then lower revs when choke off. Sounded lovely!

Took her for a test ride down the road, 30mph nicely up hill. Great! Then we had a pop like a back fire, and she died!

She turns over and still has a spark and has fuel at the carb. Just won't fire.

I'm now lost at what to try. The bike has had all new parts other than the carb body.

Any suggestions that I've not tried would be greatful.

Thanks in advance.

Mark

 

is it sucking fuel air mix into cylinder ? ie plug well wet after trying to start for a bit ? did you make sure needle jet seated right before reassembling carb ? did you fit new gasket when changing reed ?

 

I've not checked that the plug is wet. Needle jet is seated tight. Tested the choke was working. New Reed gaskets on top and bottom. When I took the old reeds out, there was no gaskets. It still had the original anti tamper bolt fitted by Peugeot.

 

Try starting for a good while and check to see if plug wet

 

The plug isn't wet but is showing that it was burning good when running. The fuel filter/tap are only 6 months old. Fuel is getting to the carb as when I cover the carb with my hand, fuel floods out. When I put my finger over the sparkplug hole, it is pushed away when turning her over.

This is the most simplist engine, but it gives me more issues than my zx6r!

I'm grateful for your input though.

 

First thing............10psi will push your finger off the hole!!!!!!!!
That is no indication of good compression!

If the plug is staying dry then no fuel is getting to the cylinder.
Is the carb bowl getting the right amount in it? Putting you hand over the back will obviously draw fuel out, again that's no indication that it will draw fuel in, you need the compression downstroke to do that.
Beg, borrow or buy a compression tester, about £30 from loads of places, makes things easy to rule out quickly, even on the zx....

 

I get what you are saying. It's me trying to tell myself that there is some compression there, so it should run.

Trying not to do too much to it as I know come December/January time when she is 17, she wants a geared 125cc.

Looks like rings, piston and bore change time.

It makes sence that it's gone. new reeds, causing it to need more vacuum to open them, giving more strain on worn rings.

Thank you for both your input.
Mark

 

f fuel not being sucked into cylinder but float bowl is full , it has to be blocked jet/atomiser or air leak at manifold , put your hand over inlet of carb turn engine over and see if your hand is sucked hard against carb , if not then the engine is sucking air in somewhere else, so by process of elimination work through all joints , if you not using oil injector make sure it`s blocked off , surprising how many people don`t , same with rubber gasket in carb top cover , try spraying a load of WD40 or similar around joints as you turn her over see if it fires up for a moment . good luck

 

Hand gets sucked but flooded my hand with fuel. Took reeds off to make sure they were OK. Stupidly, I had missed 2 gaskets I didn't remove, now removed, sprayed wd40 all over, but still not starting. Think I'll take the barrel off at the weekend to see what the condition is like.

 

if what you had not removed was stopping the reeds from opening it should start now you have removed it , you will be surprised how much turning over it takes to start a 2t if crankcases have been dry , take a look at plug again before doing major work if now wet but not starting , f*ck knows but I have flattened a battery nearly twice spinning up a "dry" engine , should start now ?

 

Sorry its been a while, but I've had a few issues with "friendly" neighbours complaining about other tenants so didn't want to rock the boat by stripping the Peugeot.

Well, I took the head off and looked down the bore, looks shiny and OK. Piston head looked OK, a bit of carbon, but ok. Decided to take cylinder off and have a proper look at the rings and piston.

Well, other than the piston is 14 years old, I think that the picture shows why it didn't run.

 

Picture wouldn't upload.