Can spark plugs cause power loss at certain RPMs?

[Badooka]

Check those coils- and the wiring going to them.

[gs11ezrydr]

I second Badooka I would check and clean and tighten the connections at the coils, I have even put a small bead of solder at the coil connection, (primary) and (secondary) wires and cured the high resistance condition. Fixed a lot of ignition conditions in the early 80's with this little trick after being through several other dealerships. Tighten and olm test the caps. Just a thought. Also get the proper heat range , your messing with borderline detonation possibly. Throw those Champion plugs away!!!!! They are for Briggs and Stratton

[trippivot]

better learn the learn the spark plug construction code.

A BPR8 type plug has a projected tip in comparison to a B8 so I hope you did not smack the piston with your spark plug tip.

[tkent02]

Detonation.

Ah, yeah good point. I forget that anymore since
I live and ride mostly at high elevations.

[safwan.khan]

Thanks for the input mate. I'll have a look at those coils as well!

I second Badooka I would check and clean and tighten the connections at the coils, I have even put a small bead of solder at the coil connection, (primary) and (secondary) wires and cured the high resistance condition. Fixed a lot of ignition conditions in the early 80's with this little trick after being through several other dealerships. Tighten and olm test the caps. Just a thought. Also get the proper heat range , your messing with borderline detonation possibly. Throw those Champion plugs away!!!!! They are for Briggs and Stratton

[safwan.khan]

Fortunately that is not the case. There is enough gap between the piston top and plug tip.

A BPR8 type plug has a projected tip in comparison to a B8 so I hope you did not smack the piston with your spark plug tip.

[safwan.khan]

Do NGK dp8ea-9's match with NGK B8ES and NGK dp7ea-9's with NGK B7es? Any suggestions guys?

[Nessism]

Do NGK dp8ea-9's match with NGK B8ES and NGK dp7ea-9's with NGK B7es? Any suggestions guys?

The D-series NGK's are smaller diameter threads than the B-series.

[tkent02]

Can't you special order some NGK B8ES?

[safwan.khan]

Couldn't find a decent supplier locally. Even the so-called NGK dealers do not have these spark plugs and they refused to import since I wasn't ready to buy more than a thousand pieces from them. The next time I'll hit the market I'll probably be looking for other alternatives like Denso W24ES-U's.

Can't you special order some NGK B8ES?

[safwan.khan]

Thanks for the info bro. Actually I've seen some modern alternatives being regularly introduced by spark plug companies so was wondering if there exists a newer alternative of B8ES which I am unaware of. Everywhere I see only platinum, iridium, "awsomenium" spark plugs for "better spark" and "better fuel economy" but no genuine old school reliable parts.

The D-series NGK's are smaller diameter threads than the B-series.

[Nessism]

Did you look though that spark plug cross reference guide posted earlier? There are something like 75 interchangeable plugs for you to choose from. You telling us that none of these are available? It's okay to move up to platinum or what have you, just get the size and heat range correct and you should be good to go.

[safwan.khan]

The local market here is filled with high heat range plugs. Not enough parts available here easily. I'm looking forward to import me some from US or Japan.

Did you look though that spark plug cross reference guide posted earlier? There are something like 75 interchangeable plugs for you to choose from. You telling us that none of these are available? It's okay to move up to platinum or what have you, just get the size and heat range correct and you should be good to go.

[safwan.khan]

Finally got NGK B8ES Solid from a local seller. New out of old stock. Now all power loss problems seem to be solved and she is running SWEET as hell on higher rpms. (Price per plug: 130 PKR = $1.32) I've bought myself 10 of these. keeping 4 other pairs in my spare box.

[lrgguy]

$1.32 ?? Sweet !! Just bought 4 here in toronto yesterday cost me $5.99 each