Removed iridium plug - scooter works better !!

[Stig / Major Tom]

Hope  I will get some responses from LIKE owners who installed an iridium spark plug in their scooter..........
Did they have any issues with increased idle speed, increased stopping distances due to loss of engine braking?

My idle speed increased slightly - but the real issue was the reduction in engine braking when throttle was rolled off -- as approaching a stop.
Had to use the brakes more - and in quick stops the delay in engine slowing (back to idle) caused increased stopping distances.
Essentially I was braking against inertia and the engine.

So, with the IRIDIUM spark plug :
1) idle speed increased slightly
2) Idle smoothed and steadied nicely
3) pick-up may have been better
4) no idea re. MPG improvement because I removed the plug after 50 miles
5) stock NGK plug put back in - scoot works the way I want it to with renewed engine braking again!

[tclhb]

Thanks for thi info Stig.

[Vivo]

Hope  I will get some responses from LIKE owners who installed an iridium spark plug in their scooter..........
Did they have any issues with increased idle speed, increased stopping distances due to loss of engine braking?

My idle speed increased slightly - but the real issue was the reduction in engine braking when throttle was rolled off -- as approaching a stop.
Had to use the brakes more - and in quick stops the delay in engine slowing (back to idle) caused increased stopping distances.
Essentially I was braking against inertia and the engine.

So, with the IRIDIUM spark plug :
1) idle speed increased slightly
2) Idle smoothed and steadied nicely
3) pick-up may have been better
4) no idea re. MPG improvement because I removed the plug after 50 miles
5) stock NGK plug put back in - scoot works the way I want it to with renewed engine braking again!

Hi Stig... I'm a bit confused.....

Why would idle speed increase?   If Iridium affected timing..should the ECU have done something to adjust? Hmm....

[tclhb]

I have a 2007 Corvette. On the Vette forum when someone does mods like cold air intake, or headers, or cat back, etc., most people on the forum recommend taking the car to a good tuner. I have experienced this myself when I did CAI and my cat back. I am a little skeptical when I read things like "the vehicle has to learn the changes you've made"
Now I don't know that a spark plug is in the same category, but does our scooter tune itself such that it compensates for modifications? I would guess no.

[MotoRandy123]

It seems the stock plug isn't fully igniting the fuel during decel so creates more drag
on the rear wheel. I don't think the ECU will tune for that. They do set trims to fine tune
each engine for the best emissions by adding or subtracting fuel at each RPM. Removing
the battery for 20 minutes will usually reset the trims (and it will start tuning again). So
some people do that after a change. Not sure if it would change the engine breaking,
someone will have to try it...

[Stig / Major Tom]

I have a 2007 Corvette. On the Vette forum when someone does mods like cold air intake, or headers, or cat back, etc., most people on the forum recommend taking the car to a good tuner. I have experienced this myself when I did CAI and my cat back. I am a little skeptical when I read things like "the vehicle has to learn the changes you've made"
Now I don't know that a spark plug is in the same category, but does our scooter tune itself such that it compensates for modifications? I would guess no.

I don't have a clue about why the new iridium plug increased my idle slightly - no big deal really, but I did not like the resulting loss of some engine braking. The scoot rolled on an extra several yards after I shut the throttle down.

It was quite clear to me this was caused by the new spark plug, I put the plug in drove 50 yards and noticed at the first stop sign the difference. After 50 miles and 3 rides it did not go away (tried 2 suggestions by riders on modernbuddy forum - 3 cycles of key off and on for 3 seconds without starting scoot: disconnect battery for a time -  no affect) Since no other LIKE owner responded to my post re. the effects of an iridium plug in their LIKE 200i I did the next logical thing. (and I'm getting pretty quick at pulling the seat and front panel!)
Took things apart and put the stock NGK plug back in - 50 yards later at my first stop sign I had my old scooter back! BINGO - keep the iridium as an emergency spare under the seat with my emergency clean shorts and moon pies! Great smooth riding plug - but don't like the one side effect. The stock NGK works pretty good, too - though idle is less steady compared to the iridium plug.
My thanks for those who did offer advice!
Great forum - great scooter!
Ride safe......

[Stig / Major Tom]

It seems the stock plug isn't fully igniting the fuel during decel so creates more drag
on the rear wheel. I don't think the ECU will tune for that. They do set trims to fine tune
each engine for the best emissions by adding or subtracting fuel at each RPM. Removing
the battery for 20 minutes will usually reset the trims (and it will start tuning again). So
some people do that after a change. Not sure if it would change the engine breaking,
someone will have to try it...

Thanks Moto... I will let my fellow LIKE 200i riders try to sort the iridium plug. When they get it right, I've still got her right there wrapped safely in my clean emergency shorts and will pop it back in with the new fixes. (with that iridium plug I was starting to price new rotors and brake pads and order some.......Which is a future post ...best replacement rotors and pads - seem to be lots on the market!)

[MotoRandy123]

Well I swapped my Iridium plug back to stock today. I wanted to see if it was causing my slow to
return to idle. Well it was still slow to return to idle and it felt like I had the brakes on all the time!
I went back to the iridium for the smooth powerful feel it gives!