LCGB Forums

Hi, im currently rebuilding for a friend a SX150. Ive built the engine from an empty casing and only used top quality parts as my friend instructed. Now ive got the engine back into the scoot and for the life of me i cant get it to start my ask for help here is in setting the timing. The flywheel has no windows so you cant see the marks on the black box to line up with any corresponding marks on the flywheel. Ive got TDC and the firing point 17 degrees before and set the stator as a guesstimate . I have a timing light at the ready to check the arrow on my marks but without it running i could be a mile out!!
Is there a way to set the ignition without all the guess work? Which seems to me to be a set back on the indian flywheel. Or am i missing something obvious
Thanks.
Dave

Can you take the spark plug out (so there is no compression) and turn the engine over using a battery drill or impact driver whilst operating the timing light?

Already I am thinking that you need an extra pair of hands for this.

There are timing marks on the flywheel itself to get you in the parish.

Tony Hart wrote:There are timing marks on the flywheel itself to get you in the parish.

Yeah, I've used them but no joy, I've almost broke my leg kicking it over today (slight exaggeration on the leg) it's almost there at times then a backfire or two and nothing.

it should start even if its several degrees out, sound like you need to go back over EVERYTHING, timing marks etc.

Knowledge wrote:Can you take the spark plug out (so there is no compression) and turn the engine over using a battery drill or impact driver whilst operating the timing light?

Already I am thinking that you need an extra pair of hands for this.

I used this method myself with good results, just be aware that when spinning the flywheel you may un-fasten the nut (L/H thread).

I never checked the nut after setting the timing and consequently sheared the woodruf key

Ya ain’t got one of those dodgy flywheel with the key slot in the wrong position ?

Guys, thanks for the advice, if I can ask? How do you set the timing with the strobe light if it's not connected to the spark plug? My timing light has a plug and a spark plug connection, nothing else. Don't I need a spark to make the light strobe? Worried now if I've a dodgy flywheel
Thanks again.

Thackers wrote:Guys, thanks for the advice, if I can ask? How do you set the timing with the strobe light if it's not connected to the spark plug? My timing light has a plug and a spark plug connection, nothing else. Don't I need a spark to make the light strobe? Worried now if I've a dodgy flywheel
Thanks again.

If your ignition is working it will still generate a spark even without the plug fittrd but you will need tp earth the metal body bof the plug to the engine csds. If it doedny spark then you have found your problem

For the strob to work the engine must be running saying that if the stator is fixed with the bolts roughly in the centre of the slot it should run then as long as your timing marks are right the timing should be setable are you sure it's sparking? I am assuming the top ends basically std and you've given the carb a good clean

Carb is a brand new scootopia replica of the sh20 (I think that's the one) I have a good spark and the cyl is a Italian 150 bored to 175cc which was working fine in another engine. The carb is jetted as it came 50 pilot 50 choke and a 105 main I think. It did have 2 slides but I just Left it as it was. I know the piston is the right way on Arrow down and squish was around 1.3 mm. I'll try the drill method and see if I can establish anything that way. Thanks

I'm not familiar with the BGM stator but is it possible to fit it in total the wrong position?

Scooter should start even if timing is significantly out.

Presuming you have got a spark - have you tried a blast of easy start just to get it to fire and turn over. a bit of encouragement is often enough.

plug wet or dry ?

Thanks to all who gave advice and help on this. It turned out to be a sheared woodruff Key
All timed up as suggested with the drill and timing light, started 2nd kick.
Thanks to all again.
Dave.

your timing light would normally use an inductive pickup to trigger when a spark is produced. i.e it detects high voltage pulses in the spark plug lead

The lamp is powered from 12 volt battery the switch to flick on the strobe light is a transistor that switches on the lamp only when it sees a pulse from the trigger clamp. that pulse happens when the spark plug fires

put the trigger clamp round the spark plug lead with its arrow facing the plug. timing will be 1-3 degrees out if you put it backwards.
power up the light by connecting it to 12 volt battery
the crocodile clip lead is not used when setting timing. its for general test light work, static setting of points based timing and if the timing light does it dwell setting...you don';t need it here

rest the plug on the engine cowl and every time it sparks your timing light strobe should fire. doesn't matter if the motor is turned over under its own steam or you are winding it over by hand. provided it turns a spark of sorts will be produced.

something to spin the crank the correct way from either end, cush-drive or flywheel is key as the work you need to do checking the timing can't be done while running down the road.

kick back at the kick start MIGHT be an indication of far too advanced. i.e the ignition event tried to make the crank spin backwards. This will break stuff

back fire can be a multitude of things but again can be linked to way too much or way too little advance. i.e you are igniting a charge when the exhaust port is somewhat open at or very soon after ignition..... hard to do as there is little/less compression if it is open which is why it does it only infrequently. to Go off pop you are not necessarily igniting the last induction stroke of properly mixed fuel and air ... it will be quite wet in there it will be a function of what is evaporating more than anything else luck (bad) rather than timing in some cases

dave

Dave