spark plug recommendations

hello i just got my xj and it has autolites it runs fine but i wont to see what other guys have in there bike im going for performance so any plugs better then others for that?

 

NGK BP7ES for a 1981 XJ650 Maxim.

 

Or if you are North of border bpr7es and can splurge and get bpr7ev

 

Plugs (other than having the correct heat range, resistance (or no resistance) and gap) have very little to do with how an engine performs. NGK is my prefrence because they were the OEM supplier for Yamaha, but any plug that crosses correctly will do. There is no bebefit from running a fancy plug on a stock engine.

 

...unless it makes you feel fancy!

 

im sorry didnt even say what she was xj750 maxim and i live in sc.

 

Oh they are less prone to cold fouling and come to temp and stay cleaner longer and are good for twice the miles and I don't baby my bikes never have well maintained and can take a good thrashing without quitting!

 

Yes the plugs are better, but they don't make the engine perform better.

 

Same plugs for my '82 650j (running stock plugs make troubleshooting easier for me). It f@#ks with me when something is suppose to read the same on the DMM as stock but doesn't.

@k-moe: Agreed.

@toomany: Also agreed but I wouldn't run resistant plugs with resistant caps.

Explanation: Both will perform to spec but the later should perform better than oem and last longer . Kinda like wet cell and agm batts, or stock coils and dyna. Imo the oem parts yamaha used on these bikes were the sh!t for the era.

Gary H.

 

That would be becuse they were dead-set on surpassing Honda (and they came damned close to doing so).

 

Required in Canada after 1977 model year all yamaha's , honda etc came with resistor plugs and the standard 5k ohm caps. It even listed resistor and non resistor plugs on parts fiche for canadian, us and California bikes

 

You are the Master of Those Who Know............

 

Hi Len did you know.... Of course you do your Len! Your intimate knowledge of xj's is amazing and most of us would cry in our beer over the problems we have with our bikes and sell them off as parts bikes if not for XJ4Ever !

 

+1...and this forum. Many of these bikes have low milage because as problems occurred the owners weren't equipped with enough knowledge (tech manuals only explain so much; there's a reason for that) or $ to properly fix them so they parked em. I think I tingled a bit when I googled this site specifically for this series bikes and almost sh!tted when I found out about Xj4ever. Can't get it better. Talk about good sh!t I grew up on (staples in the country's fabric) that truly help people become and stay decent folks slowing going away and disappearing...

Gary H.

 

Len knows more than I do. He's just being humble by deflectiing your attention.

 

Oh Great Master, don't be so sure..........

 

This argument is silly. Akin to fighting over how many angels can dance on the head of a pin.
Who runs THE shop for XJs? Len has saved more of us than can be counted! K-moe has rescued his scores as well, and his lubricant info can't be beat. Hogfiddles' farm/carb clinic is a hospital for sick XJs, with spares for anyone who needs help. Rooster seems to be a robot made of electricity, cuz he understands wiring like i know the back of my hand. BigFitz is some kind of absentee genius. Hasn't been on in months, and is still shepherding the noobs into safe pastures. So many helpful folks here! Don't wanna forget anyone; Stumplifter, Polock, Rocs, RicCoMatic, the whole gang! Big shout out to all the gurus who make this site worth visiting.

Wow, that was a bunch of warm fuzzies!

 

Everyone contributes. We're all in this together.

Gary H.

 

I love Matti!
Seriously, I learned everything from everyone else here; applied their knowledge, found that they are correct and try to pay it forward whenever I can.

 

That's the attitude that makes this work! Trolls get shamed out of our life, and decent humans help each other out!
Also gotta thank the SnoSheriff, we'd be typing notes to ourselves without him.

Also wanna thank Mom, the Academy, um... Jeebus, George Clinton, myself...
(cue orchestra music to shut this clown up!)

 

Put in fancy E3 plugs early last year (guess I bought the hype) and they split in less than 6 months. Went back to good old NGK.

Properly tune the engine and that's what makes it sing.

 

+1, +1, +1 matithunder...spot on... Can't say enough good things to the heavy hitters on here.. Yall are truly appreciated!!

 

Looking for plug opinions. These only have 100 or so miles, but I'm still in the process of fine tuning after the rebuild. Bike runs well, but the tuning still needs dialed in. To me, my plugs look a bit rich, with the soot around the edges, but the tips of the plugs are still pretty clean with a grey-tan coloring.

All four plugs look identical. The pictures are of 2 and 3

 

i think they look fine, check them again at 500 miles. that soot should be there, just like it is. good job