Im going to run a NGK B5HS spark plug....

GoldenMotor.com

Venice Motor Bikes

Custom Builder / Dealer/Los Angeles
Mar 20, 2008
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The NGK 5 is a hotter plug than a 6... I run a 5 in the winter & a 6 in the summer.

To answer your question, a hot or cold plug will not make your engine run any hotter or colder, but the amount of heat from your engine can make the plug run too hot or cold; (& a plug thats running too hot or too cold can make your engine run like s**t!!!)
A plug thats too cold isn't hot enough to burn off all the gas & oil that builds up on it & can foul out; A plug thats running too hot can get glowing red hot spots & cause pre-ignition!!
Thats why when my engine starts running hotter in the summer, I switch to a slightly colder plug (& visa-versa).
 
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fall_down_stand_up

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Apr 26, 2009
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I put it in this morning and ran for about 3 miles and I think I hear it pinging....Im going to go out for a long ride right now and see how it does....Willl report back to you....Thanks for the replys....
John-John
 

Rockenstein

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Feb 8, 2009
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IMHO a 5 is too hot with the stock timing...and I didn't like a 6 much either. I tried a 9 but it wouldn't clean itself very well on a 32:1 mix and stock timing although it remedied the indications of detonation I was hearing and seeing on the other plugs I tried. I've put about 1200k on a BPR7HIX, a 40:1 mix and slightly retarded timing...at 2110 km the plug is clean, idle is low and smooth and my GPS says I top out at 54 km/h

With regards to how I tweaked the timing...I don't use the key that fixes the magnet rotor to the crankshaft.
 

fall_down_stand_up

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granbury
After the ride I can honestly say I can tell no difference....There is no pinging and it runs the same....I moved the needle down a notch and it still runs the same....Im going to move it up a notch and see how it does....
John-John
 

BarelyAWake

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Jul 21, 2009
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I ran a B5HS all summer, WOT and distance trips (1500 some-odd miles) - never had a problem w/it. I just switched to a B6HS and so far have noticed no difference at all.

I ran the B5HS simply because that's what was available at the time, I switched to the new B6HS because the B5HS was becoming lightly corroded on the outside and it annoyed me to see it :p

gdang ocean o_O
 

fall_down_stand_up

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granbury
Bikes running the same after moving the needle up a notch....You would think there would be a difference....
Im going to keep this plug in and check it at the end of the day to see how its burning....
John-John
 

BarelyAWake

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You runnin the stock carb ona 66cc? If so - is it the old style or the new one with the second fuel petcock on it?
 

Venice Motor Bikes

Custom Builder / Dealer/Los Angeles
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You're not going to feel any difference between a #5 & 6 plug.
Like I said before, plugs don't give you better performance!! The wrong plug will either foul out in really cold weather, or cause detonation in extemely hot weather...
 
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BarelyAWake

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...The wrong plug will either foul out in really cold weather, or cause detonation in extemely hot weather...
These were the differences I didn't notice ;)

BUT the winter here has just started and leave it to me to be absolutely backwards with the heat ranges, 5 in the summer anna 6 in the winter :D

I'll get back to ya on this in 'bout a month or so lol
 
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Bikeguy Joe

Godfather of Motorized Bicycles
Jan 8, 2008
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Remember the stock plug?
These engines aren't real particular about what plug they use, as long as it doesn't hit the piston...
 

bairdco

a guy who makes cool bikes
Aug 18, 2009
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i've been running a 7, just because i was always hammering around at top speed all summer, i wanted a colder range.

it still works fine now that it's colder (65 degrees, brrrrr,) but i might go to a 6. but i might not. depends on if my bike starts acting up.

as far as the stock plug goes, the extra one i got with my kit was cracked, probably from rolling around in the box. it was a hairline crack, and if i was new to all this, and didn't know what a spark plug was, i woulda installed it.

then i'd be on here asking "does anyone else have a two-piece spark plug?"
 

tyrslider

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fdsu , your needle only effects throttle response between 1/4 & 1/2 throttle. It goes something like this 0-1/8th throttle is idle air (mixture screw not usually on these carbs), 1/8th-1/4 = idle jet, 1/4-1/2 = needle jet and 1/2-wot is main jet. To check proper needle adjustment you'd need to do throttle chop / plug checks at 1/4-1/2 throttle. On plugs you want to run the coldest plug that doesn't foul. When running too hot a plug you may have detonation (preign) w/o knowing and reduce longevity considerably w/ no gains.