75 GT 750 M Spark Plug?

[garyr]

Can someone tell me the stock spark plug for the 75 GT 750. I just got the bike and it has B6ES in it. It has been jetted with Pod filters and the color of the plug looks fine. I have 5 repair books and they call for NGK B8ES as stock? Is that right because the books I think are referring the first model year.

Thanks.

[Jimroid]

Item #12. http://www.partzilla.com/parts/search/S ... parts.html" onclick="window.open(this.href);return false;

[garyr]

Thanks...SPARK PLUG | M,A,B; NGK B-8ES FROM 09482-00056
09482-00091

That's 2 heat ranges hotter than I have now....Yikes.

[Jimroid]

An 8 is colder than a 6.

[tz375]

Fortunately most of us don't ride hard across the desert so we can often get away with hotter plugs than back in the day. Another thing is that unleaded gas leaves more carbon deposits on a plug that require a hotter plug to burn clean than leaded and even though they were designed to run on almost anything north of kerosene, one step hotter is rarely an issue. Two steps is a bit of a jump though.

I have run 8s and 9s at the strip and even thrashing it for 12 or so seconds at WOT leaves little or no sign of overheating on the electrodes.

If your timing is slightly retarded to compensate for lower gas octane levels than back in the day, even 6s are OK around town, but check the plug tips for signs of overheating and it you run it hard in the summer or on a cold evening/morning when the air is dense.

I would run 8s just to be as safe as possible, but I would not be surprised if your bike never misses a beat with 6s if you just pootle around and don't let it work hard.

The thing about plugs is that they are designed to run within a certain temperature range and load really pushes up the temperature more that the heat range's ability to dispose of it. Run it easy and plugs don't get too hot.

[jabcb]

You can also juice your ignition system up a bit by switching to fine wire plugs.

For non-resistor plugs with resistor caps: B8EGV (resistor caps are stock)
For resistor plugs with non-resistor caps: BR8EIX

[garyr]

Fortunately most of us don't ride hard across the desert so we can often get away with hotter plugs than back in the day. Another thing is that unleaded gas leaves more carbon deposits on a plug that require a hotter plug to burn clean than leaded and even though they were designed to run on almost anything north of kerosene, one step hotter is rarely an issue. Two steps is a bit of a jump though.

I have run 8s and 9s at the strip and even thrashing it for 12 or so seconds at WOT leaves little or no sign of overheating on the electrodes.

If your timing is slightly retarded to compensate for lower gas octane levels than back in the day, even 6s are OK around town, but check the plug tips for signs of overheating and it you run it hard in the summer or on a cold evening/morning when the air is dense.

I would run 8s just to be as safe as possible, but I would not be surprised if your bike never misses a beat with 6s if you just pootle around and don't let it work hard.

The thing about plugs is that they are designed to run within a certain temperature range and load really pushes up the temperature more that the heat range's ability to dispose of it. Run it easy and plugs don't get too hot.

Thanks....I found 6's in the bike and they looked lean but also had antifreeze on them. The guy has pod filters so next I'm going to pull the jets and see where he is at. I'm going to go 2 up from whatever he has in there and I bought the NGK 8's. It's just each book I have called for 7 or 8 as stock for the M.

Yes my other post I thought they were hotter the higher number. I'm 75 feet above sea level and its mostly in the mid 80's in the summer here and could be humid. I always use stock plugs and needle settings and just go larger on mains and pilots when jetting.

Thanks for the great info TZ375!!