Piaggio Zip not starting??

I have recently put a new pm tuning 70s kit on my Piaggio Zip due to it blowing up, I got someone to jet it with a 17.5 carb, airbox and yasuni r, it’s running a 75 jet.

The bike worked fine for the first 4 or so days but was always fairly hard to start taking around 10 kicks.

I went out yesterday and came to a stop so I turned the bike off and since then it has not turned on, it occasionally turns on for about a second and then cuts out.

I have replaced the spark plug and getting fuel to the spark plug with a strong spark.

I have not checked compression but considering it has slightly started for a second and also have only done around 600 Miles on the kit it shouldn’t be that.

I need some urgent answers because I need to commute to collage this following Wednesday.

Cheers.

 

If the plug is getting wet and you have a spark, then suspect the compression, do the test.

 

agree with compression test, base gasket could be a problem. soapy water for a quick check, if all is good give the carb a service.

 

I’m getting a mechanic around tomo I’ll let you both know what the problem is. Cheers for reply’s.

 

Is it possible it could be the stator fryed that’s what’s a few people have said?

 

I have a similar problem, and turns out to be the regulator, which is supposed to keep the voltage low to the bikes circuits. the thing is you say you are getting a good spark which would rule out the stator and CDI as a problem, check your battery voltage when it cuts out. the ignition circuit has a coil of its own on the stator and other coils go to the battery charging circuit and lighting. does your starter motor run, if so check the voltage running to the regulator. if a stator produces too low a current/voltage then it is a problem. you should read about 80V AC at the CDI (green wire) and I think 25V ac at the regulator (not certain) your regulator will be an 8 pin or 5 pin, the voltage to the battery should not exceed 14.5 volts when charging
here is a wiring diagram from a gilera runner which uses the same regulator/rectifier as mine (8 pin) . hope it can be some help as if yours is 8 pin the numbers should read rcb 100.01

 

Yeah cheers, I know for a fact that the thing connecting to the spark plug has a spark but I’m not sure it’s sparking when it’s in the cylinder, tomorrow i will take out the spark plug and check it is sparking.

 

The "thing" connecting to the spark plug is called the HT lead, HT standing for High Tension.
If you want to know if it works, put your finger over the end and crank the bike.

NO, NOT REALLY, DON'T DO THAT!!!!
Put it to the cylinder head as you would a spark plug...........................

 

Yeah, also is there any chance it could not b starting because of auto choke may b faulty?

 

That would make it harder to start yes, but you can confirm the operation of the auto choke by taking it out and wiring it direct to the battery positive and negative. If it works the brass plunger should extend by about 8mm within a minute or so.
The other thing to check is whether the plug is getting wet with fuel after it is cranking and NOT starting. If the plug is dry after loads of cranking and not starting then there is a fuel issue, if it's soaking wet and not starting there could be a compression issue. This is providing of course that you have a good spark to start with.

 

I cranked the bike over and plug is dry, I took apart the carb and there seems to be a bit of fuel in the carb, the jets ain’t blocked, what else could it be stopping fuel get to the spark plug? Reeds?

 

your fuel tap has 2 hoses the larger one is the supply the smaller one is the negative pressure, disconnect both hoses from the carb. suck on the smmaller one to see if any fuel comes through the bigger one. when running the vacuum of the carb creates the suction so fuel is always supplied to the carb. how did you check the jets, did you blast them with wd40 or air duster, sometimes you can't see the blockage. also it would likely be the pilot jet that would be blocked. blast all the fuel channels in the carb with wd40 or similar with the plastic tube in the nozzle.

 

Alright will do, I sucked on the vacuume and fuel came out the other hose so yeah, before I only really looked and blew abit through the main jets hole.

 

And if the plug stays dry, do a compression test.

 

When I sucked on the vacuum and fuel came out I poored some fuel on the spark plug and put it back in then tried to start bike and it started twice in a row but when I throttle it cut out, so the last thing I should check is pilot jet incase it’s blocked and then compression test ?

 

I also cranked the bike over with the fuel line disconnected and each time I kick fuel comes out

 

I held on the float chamber and connected the fuel line but had the vacuum disconnected, I sucked on the vacuum and it only allowed that much fuel before shutting off, how do I adjust this to have more fuel?? Adjust float height?

 

I have a dellorto PHVA 17.5 yours looks similar. take your float off and there is a small pointed needle which goes inside the inlet. blast through the inlet with the wd40 (lighter fluid / butane any oil based pressurised liquid which ignites) clean the components and you should get fuel when you let the float hang down, while sucking the negative pressure.

 

So I should spray wd40 through that hole ?

 

The same amount of fuel came out intull it shut off