Spark Plugs

[mvk24_imp]

Hey guys, 6 years later are there any other spark plug options out there now? I had my ECU flashed by Guhls, Speed limiter and Ignition Timing, didn't get to ride it much this winter but now that I've been out for a few days the bike has plenty of power but doesn't want to just "Cruise". I used to do 60-70mph in 6th gear no problem (alot of highway). But now it barely wants to maintain 80mph without acceleration in 6th gear. Even in 4th or 5th if just feels like it wants to bog out unless I'm accelerating. And the slightest twist of the wrist almost makes it jump at those speeds.

I just went over the 10k mile mark, stock headers, Shorty GP exhaust tip, ECU flash by Don for speed limiter and Ignition timing, Honda CB500 handlebars, everything else is stock.

I checked the air box and filter - Clean no issues
Changed the oil and filter to Honda GN4 new formula( whatever it's called) oil
Pulled the plugs and they looked almost perfect, little white on the top and little black on the threads so I put them back in and it was still doing it.
So last night I pulled the plugs, hit them with WD-40 and gave them a gentle nylon brushing to clean and gap them.
Put them back in today and I'll see what happens but the only thing I can think of is maybe it just needs new plugs? But can't find them under LMAR8A-9S now?

I have also noticed the top crankcase breather has been full again in the last 500 miles, the bottom has been bone dry, the oil already looks like cuss ans low in the window and I literally just did the oil change maybe 500 miles ago with no obvious leaks... I kinda wanna change the oil and plugs and see where this goes but do we have any ideas?

Valve cover was done by my local shop when they sent the ECU to get flashed so if anything was weird in there I would've known back in October when it was open.

I think that's a long story to get to the punch line of - should I change the plugs and what options are out there now in 2019
Wait also when I checked the plugs the first time I forgot to put the harness back on the far right plug and started it. Ran it for maybe 5 seconds and when it didn't sound right I realized I forgot to cap that plug and turned the bike off. Almost seems like the cruising issue has been since then? Could the brief misfire have messed up the ignition timing or plug somehow?

[Houtman_imp]

I am not so certain that it is the plugs, could the reflash perhaps messed things up ?

[mvk24_imp]

I am not so certain that it is the plugs, could the reflash perhaps messed things up ?

I was thinking that also but I've put a few hundred miles on it since and the gearing didn't feel great but this lack of "Cruising" RPMs wasn't really noticed until now.

[Houtman_imp]

Did you cruise in the previous miles or perhaps shorter trips and concentrating on other characters of the bike/ride ?

[max]

One thing is not clear to me; did you ride the bike for a while after the reflash with good results and now it has changed it's behavior?

And secondly; are the plug caps properly making contact with the plugs?
I know it is a silly question but i have actually done that and wondered why my ( other ) bike would idle fine but run on three cylinders when accelerated.

[jimgl3_imp]

$12 on amazon

https://www.amazon.com/NGK-LMAR8A-9S-Spa...B006DI4AT0

[mvk24_imp]

After i got it back i noticed it felt weird but didnt get to ride it much till the season just started. I spoke to my guy at the shop and he wants to do a dyno run to see if my F/A ratio is off since there is no power commander. Any suggestions? not rolling in it right now for $150 dyno diagnostic just to tell me i probably need to buy a fuel controller. He said its going to be the cheapest and fastest way to to a diagnostic but Don re-flashes for free if i pull it out myself right?

$12 on amazon

https://www.amazon.com/NGK-LMAR8A-9S-Spa...B006DI4AT0

Thank you! added to the cart

[itstuantran_imp]

This is my option for my CB1100 RS: NGK SILMAR9B9 Iridium Spark Plug
Compared to stock, heat range is 1 level higher.
This is recommended by my friend after 5000 km trial through various weather condition (exclude snowing), reported running good and smooth, a bit more responsive. I've tried on mine for 50km so far and could say it's a bit more responsive to stock spark plug, none other issues so far, will report if any.
My current setup is:
- Titanium Motogears headers
- Marverick 83 carbon muffler
- Bazzaz ZFI
- KN air filter
- TSR air funnel

Hey guys, 6 years later are there any other spark plug options out there now? I had my ECU flashed by Guhls, Speed limiter and Ignition Timing, didn't get to ride it much this winter but now that I've been out for a few days the bike has plenty of power but doesn't want to just "Cruise". I used to do 60-70mph in 6th gear no problem (alot of highway). But now it barely wants to maintain 80mph without acceleration in 6th gear. Even in 4th or 5th if just feels like it wants to bog out unless I'm accelerating. And the slightest twist of the wrist almost makes it jump at those speeds.

I just went over the 10k mile mark, stock headers, Shorty GP exhaust tip, ECU flash by Don for speed limiter and Ignition timing, Honda CB500 handlebars, everything else is stock.

I checked the air box and filter - Clean no issues
Changed the oil and filter to Honda GN4 new formula( whatever it's called) oil
Pulled the plugs and they looked almost perfect, little white on the top and little black on the threads so I put them back in and it was still doing it.
So last night I pulled the plugs, hit them with WD-40 and gave them a gentle nylon brushing to clean and gap them.
Put them back in today and I'll see what happens but the only thing I can think of is maybe it just needs new plugs? But can't find them under LMAR8A-9S now?

I have also noticed the top crankcase breather has been full again in the last 500 miles, the bottom has been bone dry, the oil already looks like cuss ans low in the window and I literally just did the oil change maybe 500 miles ago with no obvious leaks... I kinda wanna change the oil and plugs and see where this goes but do we have any ideas?

Valve cover was done by my local shop when they sent the ECU to get flashed so if anything was weird in there I would've known back in October when it was open.

I think that's a long story to get to the punch line of - should I change the plugs and what options are out there now in 2019
Wait also when I checked the plugs the first time I forgot to put the harness back on the far right plug and started it. Ran it for maybe 5 seconds and when it didn't sound right I realized I forgot to cap that plug and turned the bike off. Almost seems like the cruising issue has been since then? Could the brief misfire have messed up the ignition timing or plug somehow?

[mrded_imp]

Do you know what socket do I need to remove a spark plug?

I’m really getting confused as someone in comments was saying it’s 14mm but my service manual is saying the thread is 10mm.

does it mean a nut is 14mm, and I need to look at a socket size by a nut size? Will the one I bought work?

[the Ferret]

In metric the head is usually 4 mm larger than the thread so a 6m bolt or nut takes a 10 mm tool

An 8mm thread bolt would take a 12mm wrench

On the spark plug the thread is 10 mm but the tool is 14 mm