speedfight2 non-start

[andyjonc]

first of all an apology: i know it's likely that this topic has been discussed in the past. i HAVE tried to do a search, and read many threads already, but have been unable to solve my problem so am posting a new thread. please be gentle with me

i have a speedfight2. it used to run. then it sat in my shed for a couple of years. now i cannot get it started.

i currently have it connected to a good battery, i have checked spark (both seen spark on cylinder head and using a spark tester), i have fuel flow (with fresh fuel - checked carb, pulled hoses, observed fuel flow), i have removed exhaust in case it was blocked, when winding engine over using starter can see exhaust/unburnt fuel exiting exhaust port. i have checked compression and it has 60psi (i do not know the spec for this though so this may be too low?)

do all speedfight2's have an immobiliser? i didn't think mine did, but have read this as a possible fault on previous threads.
could it be the auto-choke? i don't know a lot about these

electrics on scooters aren't a strong point, but i would expect that if fuel is getting in, there's a spark, and a free exhaust... then the engine should run surely??

i am at a loss... can anyone help??

many thanks in advance!
Andy

[Renaulttom]

Red light on the clocks ?
Clean carb?
My friends speedfight did this it was the immobiliser

[andyjonc]

ok so i reattached the exhaust just to double check the compression stayed the same. it stayed at 60psi.

i then noticed my compression tester was using a rubber extension hose... surely that would swell and affect the pressure reading?? so i removed that and connected directly to the metal connector. compression went up to 80psi. better but still too low.

so i put a little bit of oil in plug hole and refitted the spark plug. when i thumbed the starter it still didn't fire but did cough, once. encouragement!

i put my thumb over the exhaust and after a few spins the engine fired! it started!! i can only assume that blocking the exhaust momentarily, increased the pressure in the cylinder and helped the fuel ignite?

lot's of smoke but it's running. happy days!

[Renaulttom]

Maybe could do with a de-coke

[andyjonc]

in reply to your original message renaulttom, there are NO lights on the dash, which is strange, but then i dont have all the lights etc connected at the moment.

yes a de-coke sounds like a good idea... umm how does one do that??

[Renaulttom]

head off clean it of all coke clean the top of the piston when the piston is in the barrel check for any play

[andyjonc]

Originally Posted by Renaulttom

head off clean it of all coke clean the top of the piston when the piston is in the barrel check for any play

cool thanks tom, can the head be removed in-situ? just clean it up with generic carb cleaner type spray can ok? cheers

[Renaulttom]

You can remove the head and clean it all up and if you have a blow torch clean the exhaust port then dip it in oil