Scooterotica

I've rebuilt an engine and pulled the bodywork off to replace loom & cables. At this point I have the engine in the frame and fired to do the timing. It's back firing all over the shop and sounding s**t. Would this be because I have no earths attached other than the CDI? Or should it run as normal without the earths attached?

If it's not the latter then I'll work my way back from the plug!

It should run, provided -

1. The stator white is connected to the earth on the engine and good.
2. The CDI is earth properly to the frame.

Backfiring is usually due to bad timing.

might be worth connecting a wire from the casing to the frame to be on the safe side

Turns out I'm shearing woodruff keys do they come in different sizes....just to f@@k you up like

The woodruff key is only there to ensure the flywheel is correctly aligned on the crank, it's the taper and nut that stop it spinning. You are either not tightening the flywheel nut sufficiently or the taper needs lapping in with some grinding paste.

Take the stator out and get some fine grinding paste. Place a little smear on the crank taper, fit the flywheel without the key and rotate the flywheel till you get a nice even grey finish on both mating surfaces of the taper. Clean it thoroughly refit the stator and key check the key is a good fit in the key way, then refit the flywheel.

Does your torque wrench work left handed ? Some do not.

Is it possible to fit an li flywheel to gp crank or vice versa?

If it is, then could that be the cause of shearing?

I normally shear mine when I'm setting the timing, I'm always tempted to just nip it up after moving the stator a bit then do it proper job at the end. I lapped it in and replaced the key and then all ok. I don't use the old earth to flywheel casing on any of mine. The engine is earthed through the CDI, make sure to have a good earth to the frame.

It's not an LI crank. It seemed like the the key slot was deeper on the meceur crank than the BGM. I'm off to Whitby at the weekend so I'll source some woodruff keys.

And yes I have a LHT Torque wrench

psychedelicropcircle wrote:It's not an LI crank. It seemed like the the key slot was deeper on the meceur crank than the BGM. I'm off to Whitby at the weekend so I'll source some woodruff keys.

And yes I have a LHT Torque wrench

Make sure it torques in the opposite direction (left handed)I thought mine did,until I realised it just ratcheted in that direction.