gilera runner wont start (help please)

hi so heres what happen

got a full engine rebuild on my gilera runner 172,
drove about 20 miles (after i warmed it up a few time as i was offroad for awhile) then when i went to start it one night it didnt sound normal so i warmed it up and as i drove off it cut out.

i checked it over:
fuel, compression and a spark.
cleaned the carb and air filter
checked the reed block
cleaned the spark plug
bought a new piston (as mine was coming to a end)

didnt want to start so i replaced the battery (which helped)
when i did get it to start i left it running till operating temp then went to give it a 1/4 rev and it cut out

someone mentioned it might be the cdi unit (which i hope it aint cause i have a malossi 1 on there at the moment)

any help would be appreciated thanks.

 

What was the compression reading please? It should be 150-160psi, bike will start with lower compression but wont run proper.

 

compression reading came up with around 13 bar, 187 psi
i think i found the problem
the new spark plug i bought (which worked for about 30 miles) seemed to all of a sudden struggle to start and when it did would bog and die around 3000 rpm
so i changed it back to my old 1 and it starts fine, idles fine and reaches 6000 rpm with no problem (im running in the engine so didnt want to put too much revs)

 

Not unknown to have a faulty plug from new

 

thanks for your help, since ive put a new piston in the electric start dont seem to wanna give the plug a good spark, first kick of the kickstart and its fine ive got a electric waterpump and alarm to the battery but do you think theres any other reasons there could be a problem?

 

Maybe the battery needs to be replaced or upgraded to cope with the additional load you added to it.

 

I agree with you on that one, can you even upgrade battery?, or is there any other ways to deal with the problem, during this hot weather when I'm out on the bike it gets hot and I've got the electric waterpump on, with the radiator fan which is on a switch so that must drain some battery, my alternators working fine as it ticks of and idles on the kickstart

Another problem I've come across is my crankcasing snapped off were the rear brake caliper goes onto, which I've replaced same with the caliper and hoses and bleed it which has been fine till it I was driving and the brake level went all loose and locked the back wheel?? :/

 

You can replace the battery with a higher capacity one or even a Lithium battery instead of a lead-acid one. Measure your battery box and then check to make sure that the larger capacity one will fit before you order it.

I need to see a picture of the crankcase where the part snapped off that you replaced - from the way you describe what happened it sounds as though the threads have stripped that hold the brake caliper on, but without some pictures it's hard to comment further.

 

You should be able to find the upgrade battery for your bike here:

http://www.scootershack.co.uk/threads/yuasa-battery-upgrades-for-all-bikes.34071/