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LT? Pickup? Something else?
Posted: Tue Apr 24, 2018 11:01 am
by Marty ULC
Would I still get a spark with a failing LT coil?
GT186 BGM ac stator.
Usually starts first kick every time.
Died on way home last night.
Plug dark brown.
Fuel flow seems good.
Decent looking spark.
Compression seems okay.
Just backfiring out of the exhaust when bumping or kicking even with easy start down the carb.
If it's likely to be the LT coil I'll just get a lukas cdi but would there still be a spark if the lt has gone or is it likely to be something else?
Re: LT? Pickup? Something else?
Posted: Tue Apr 24, 2018 12:24 pm
by Toddy
Marty ULC wrote: ↑Tue Apr 24, 2018 11:01 am
Would I still get a spark with a failing LT coil?
GT186 BGM ac stator.
Usually starts first kick every time.
Died on way home last night.
Plug dark brown.
Fuel flow seems good.
Decent looking spark.
Compression seems okay.
Just backfiring out of the exhaust when bumping or kicking even with easy start down the carb.
If it's likely to be the LT coil I'll just get a lukas cdi but would there still be a spark if the lt has gone or is it likely to be something else?
Reed Petals ??
Re: LT? Pickup? Something else?
Posted: Tue Apr 24, 2018 1:12 pm
by Muppet
pick up is my guess
Re: LT? Pickup? Something else?
Posted: Tue Apr 24, 2018 1:16 pm
by Marty ULC
Would it still spark if the pickup was faulty? Electrics wreck my head.
Re: LT? Pickup? Something else?
Posted: Tue Apr 24, 2018 1:24 pm
by coaster
It should fire up even if for only a few seconds if it has fuel and a spark providing the spark is happening when it should. Is it possible that the flywheel has shifted? also worth checking the pickup.
Pickups are fairly reliable tbf, possibly it is loose? or even an iron filing bridging the gap at the firing point?
LT coils often fail intermittently so I wouldn't rule it out, have you checked the resistance values?
Re: LT? Pickup? Something else?
Posted: Tue Apr 24, 2018 2:32 pm
by Marty ULC
Didn't get home until after 11 so wasn't able to check resistance
Re: LT? Pickup? Something else?
Posted: Tue Apr 24, 2018 3:59 pm
by Adam_Winstone
I have recently suffered 2 pickup failures, the first going from a bike that revved cleanly throughout the range to a bike that I had to limp home on tickover... any revs and it died. The replacement pickup then made slight contact with the flywheel and failed on my first ride out. In this case the bike was sparking really well but would not fire or run, regardless of having fuel, change of plugs, etc. A change of pickup again and everything is now fine.
Re: LT? Pickup? Something else?
Posted: Tue Apr 24, 2018 7:31 pm
by Muppet
Marty ULC wrote: ↑Tue Apr 24, 2018 1:16 pm
Would it still spark if the pickup was faulty? Electrics wreck my head.
yes but it sometimes backfires out the exhaust
Re: LT? Pickup? Something else?
Posted: Tue Apr 24, 2018 10:14 pm
by stew
20 years ago the first thing to upgrade on a Lammy would've been the stator, I'm sure we never had the same issues or am I looking back with rose tinted specs.
Re: LT? Pickup? Something else?
Posted: Tue Apr 24, 2018 11:32 pm
by Donnie
Reeds mate.