LCGB Forums

The ability to post messages is restricted to LCGB members. Any questions contact us at lcgbadmin@googlemail.com

Mag housing issue?

Need help with a tuning kit, how do you tune your scooter, which kit should I choose, and all general tuning and modifcations questions are for in here.

Mag housing issue?

Postby Fat Trucker » Fri Dec 01, 2017 6:57 pm

Evening all, I've been having issues with possible pick up misalignment. I have 3 stators to choose, 2 bgm v2/3 and a sil, all 3 have good readings on multimeter and I've 2 flywheels. I've also put a external pick up on. External pick set up is spot on and revs perfect when strobed. Tried all 3 stators with bgm flywheel and under strobe the timing mark wanders,like its pick up failure or misalignment mmm. Try stators with sil flywheel and 2 bgm stators still fail but sil works. Right I'm think I must have low pick ups on bgm stators, wrong. Measured pick ups and they all measure roughly the same height. Even so I try adding laminates to raise pick up, still no success. Add another then another until pick up box is now touching flywheel when tightened down. By this stage the big hammer needs to be hidden as I'm getting right pissed off. Sil stator and flywheel back on to see if I can see pick up alignment, although it revs out ok I can see it's not perfectly in line and the stator is sitting high.
I've a new scootopia mag housing in my scooter so I measured the internal depth from where the stator plates sit to the end of the crank taper. Then I measured the old sil mag in the old engine. The scootopia 1 is higher meaning the stator sits higher in the flywheel. That's how I'm reading it, so I now have to drop the height of the pick up to use with the bgm flywheel.
Anybody had this happen before? Any suggestions on how I go about it? File stator lugs down by the 1mm difference in both mag? Send mag back and use sil one off other engine?
Bgm stator worked perfectly fine with the bgm flywheel on the old sil mag, that's why I couldn't understand why it wasn't working correctly.
Cheers if you can help me please.

ove
Fat Trucker
 
Posts: 61
Joined: Sun Jun 01, 2014 2:22 pm

Re: Mag housing issue?

Postby NorthernJordan » Sat Dec 02, 2017 11:03 am

Are you using a thicker gasket?
Could you use a thinner one?
NorthernJordan
 
Posts: 321
Joined: Mon Jun 02, 2014 12:13 pm

Re: Mag housing issue?

Postby Fat Trucker » Sat Dec 02, 2017 1:47 pm

Good thinking Jordan, only using a standard gasket but a extra thin on might possibly be enough to work, thanks.
Fat Trucker
 
Posts: 61
Joined: Sun Jun 01, 2014 2:22 pm

Re: Mag housing issue?

Postby Fast n Furious » Sun Dec 03, 2017 3:07 am

Even with a perfectly aligned pick-up, you will normally see some variation in the timing. It's inherent by design but is usually satisfactory when the revs are piled on.
External pickups improve this greatly due the improved transition speed of the trigger signal, cos the reluctance sensor is further out on the flywheel.
User avatar
Fast n Furious
 
Posts: 1502
Joined: Sat Nov 19, 2016 3:56 am
Location: York

Re: Mag housing issue?

Postby Warkton Tornado No.1 » Sun Dec 03, 2017 8:42 pm

My apologies if I'm attempting to teach Grandma how to suck eggs, but having had the wandering timing issue on points & electronic ignitions of various types, it's always worth remembering that you cannot have 'too good an earth' connection between the magneto flange/stator & the coil/CDI/mounting.

I've got into the habit of drilling/tapping the flange for a good earth lead that stays in place rather than have the faff of the questionable electrical connection via the flywheel cover screw on the last two bikes that had that issue & it was the cure. It must be a schoolboy error that many of us have committed in strobing up an engine with no flywheel cowl fitted & therefore no earth!

As previously stated, most ignition timing swings a little for the first few thousand revs, but I have witnessed wildly varying timing due to inadequate earth connections.
Warkton Tornado No.1
 
Posts: 2112
Joined: Sun Jan 11, 2015 1:27 pm


Return to Tuning & Kits

Who is online

Users browsing this forum: No registered users and 3 guests