Tick over issues

[Snails]

Hi

My Lui 125 is now back on the road (well it will by the weekend when it passes its MOT retest) but having driven it on the road properly it has a problem ticking over when I come to stop at lights etc. Ticking over in the garage (once warm) is fine but using on the road its either wanting to die or kind of over revving...I was wondering if this is a sign of having the incorrect pilot jet?

Its using jetted as per a Vega using a sh1/20 carb with a larger main jet to accommodate its 125 ccs

[wack 63]

It's worth a try with larger idle jets, after all its a bigger cylinder .Also consider the float and needle, lean one minute, rich the next. Fuel flow thru tap, although I use a Vega tap on a 130. Plus might be best to pressure test the motor for air leaks.

[Snails]

Thanks. Will try jet first as easiest. God knows what my tap is but it ain't Vega. If it was too small you' d notice when moving along wouldn't you?

Lastly how do you pressure test an engine

[Snails]

What pilot float and needle do you have on your 130?

[wack 63]

Sorry running a PHBL 25 so no use to your set up. You can make an easy tester by using a piece of push bike inner tube with the valve connected to a foot pump. Jubilee clip it onto the inlet pipe and exhaust stub, pump up a few psi and listen for leaks and spray all around the gasket faces etc with soapy water.

[Adam_Winstone]

I don't know what carb or choke mechanism you are running but this is typical of a choke being adjusted slightly too tight or the plunger not seating correctly. You can set tickover, however, once on the road it becomes hit and miss (stalls or over-revs) as it finds additional source of fuel to mess up the fuel/air balance.

As it could be a number of other factors too... good luck solving this one.

Adam

[LI225Canada]

I was having similar issue setting up my PWK. Ended up being float height, not enough fuel in the bowl.
Did all the required modifications, checking the height was one thing I skipped when installing it.

[Snails]

Sorry running a PHBL 25 so no use to your set up. You can make an easy tester by using a piece of push bike inner tube with the valve connected to a foot pump. Jubilee clip it onto the inlet pipe and exhaust stub, pump up a few psi and listen for leaks and spray all around the gasket faces etc with soapy water.

Thanks. I take it you test the inlet and exhaust desperately rather than at the same time?

[Snails]

I was having similar issue setting up my PWK. Ended up being float height, not enough fuel in the bowl.
Did all the required modifications, checking the height was one thing I skipped when installing it.

Its a sh1/20 so shouldnt be an issue but thanks for the suggestion

[Snails]

I don't know what carb or choke mechanism you are running but this is typical of a choke being adjusted slightly too tight or the plunger not seating correctly. You can set tickover, however, once on the road it becomes hit and miss (stalls or over-revs) as it finds additional source of fuel to mess up the fuel/air balance.

As it could be a number of other factors too... good luck solving this one.

Adam

Thanks Adam I will check that out