[xpd153]

I found strange descriptions at Denso and NGK site.

At Denso.
CBR750F                                           X24ES-U           IX24
CBR750 SuperAero                          X24EP-U9         IX24B

At NGK
CBR750F                                            DPR8EA-9        DPR8EIX-9
CBR750 SuperAero                           DP8EA-9           DPR8EIX-9

 Left plug type is regular. Right plug type is premium Iridium.

 We know 1988 CBR750 dropped 'SuperAero' naming due to unknown reason. But also know Honda called it   CBR750F no matter how production year is.

 As far as I know, there is no difference between 1987 model and 1988 model regarding ignition system.
 It looks like original CBR750FH has non register type plug. Then Honda switched register type plug at FJ.

[robvangulik]

Denso plugs are used far less often, NGK is most used here.
Years ago I tried Iridium sparkplugs, and my 1000 eats them for breakfast, I mean to say they work for a (short) time and than give up, I had to replace them within 6 or 7000km, while the regular DPR9EA9 last for over 20.000km.

[xpd153]

Several years ago, I experienced similar result at NX650. At that time, NGK Iridium was not so good. I replaced it with regular NGK plug.

Denso is late comer for spark plug market. When they entered the market, NGK's reputation was rock solid.
So they focused Iridium plug.

Now, Denso has higher reputation than NGK at least Iridium spark plugs in Japan.

A couple of days ago, my NX650 had iginition problem. I checked coil,CDI, plug cap then replaced spark plug with new Denso Iridium plug. At this point, it looks like fine.

 

[robvangulik]

Always start with the easy things.....

[xpd153]

In fact, old regular plug has no problem. Just I checked all ignition related parts including the plug.
But I could not find root cause. After assembled the parts, the plug was fired up.
At that time, I had new Denso Iridium as spare. So I decided to replace spark plug. Now, old NGK plug resides in NX650 toolbox.

 Probably the root cause is poor connection of CDI unit.

 

[robvangulik]

The root cause of the problem is the age of the motorcycle, most manufacturers did not plan to make bikes that lasted 30 or 40 years, we were supposed to have bought a new bike long before that.
That said, my 1975 CB400F still runs better than new

[xpd153]

If I win some lottery, but I will not buy new motorcycle.

Because it is expensive and lacking of irresistible charm. At this point, I am satisfied with current fleet.
NX650, CBR750 and Futura.

Also I don't have huge space, not like you. Three is enough.


 

[robvangulik]

I agree about the lack of charm, I do not like how most modern motorcycles look.
I prefer a normal ( mostly round) headlight and regular exhausts under the bike.
And not so many sharp edges and angles around coolers and tank and seat.
Sounds maybe strange from a longterm CBR rider, but it is all too much Plastic Fantastic 

[xpd153]

In these days. there are many counterfeits.

https://www.youtube.com/watch?v=Lr9J3eQk-kE
https://www.youtube.com/watch?v=TYxtCC330Xg

ebay is notorious.
amazon also has many counterfeits.

[robvangulik]

I knew about the fake NGK sparkplugs, that scam is going on already for several years, but this is the first time I hear that Denso plugs are also counterfeited!