Alternative spark plugs

[Guest]

I'm getting a '79 GS400 back to life after years of neglect and I found it had a set of NGK BP5ES plugs in the engine, the manual calls for NGK B8ES. I have a spare set of BP5ES plugs, is there any issue if I continue to use these as a replacement for the B8ES or should I be worried?

I read the P menas probe or an extended probe length on the spark which you need to be careful of in case it hits the piston, it seems this plug fits ok. I also read the 8 represents the temp range it can withstand, the lower the number the higher the temp tolerance so the BP5ES should exceed the requirements of the B8ES?

[koolaid_kid]

Not exactly. In general, the lower the number, the hotter the plug.
In your case, however, all bets are off.
You would be best served by putting the correct plug in there, the NGK B8ES.
The only place I was able to find that plug after a quick search was in a lawnmower site.

[jabcb]

NGK B8ES are widely used & easy to find. Low cost & even in stock at some auto parts stores.

[GDT1960]

B8ES are commonly used in snowmobiles

[brettule]

Yeah I'm not having a problem finding them, just wondering if there is any harm continuing to use the BP5ES plug?

[eil]

I don't think anyone here can answer that question because we use B8ES as specified by Suzuki. If you really want to find out, keep them in and let us know how it goes.

[tkent02]

Yeah, what the heck. It's only three heat ranges too hot. What could possibly go wrong?

[Steve]

Yeah I'm not having a problem finding them, just wondering if there is any harm continuing to use the BP5ES plug?

In a word, ... YES.

.

[brettule]

If you really want to find out, keep them in and let us know how it goes.

Ha! I think I'll order a set of B8ES plugs tomorrow

[tkent02]

Or go down to the nearest auto parts place. $1.25 ea.

[simon kuether]

I changed from B8ES's to an equivalent (can't remember the numbers) Iridium plug .
Makes the bike to be a bit more "eager" .
They're not cheap but Toyota is the Aussie importer so if you're keen , get 'em from there .

Cheers , Simon .