2000 ox66 225 plugs ?

[misterpeabody5]

I've been running the Br9's but just installed a set of Br8's. Should I increase my octane to 89 or perhaps higher? My 9's continue to foul over time, and the engine continues to smoke upon startup, I've played with my oil pump stroke and reduced the amount of oil being injected. I always treat my fuel with sea foam and run Yamalube. anyone have any experience with this experiment?

[BuzzB8]

Continue to use the 87 octane fuel.

Trim out the engine when/while you're fishing. I trim mine out to the end of the trim rams and it helps reduce the smoke most of the time.

[Rich Z]

I hope you guys never get a chance to see what a hotter plug can do to a piston especially if one of your injectors is lean maybe then you would think twice.
I would recommend increasing the gap from .37 to .39 instead using hotter plugs. Yamaha ignition system is one of the best and can produce a spark over an inch long just at cranking speed.

[21XDC]

I have been running the 8's for 3-4 years as well as all my friends. It's only one heat range hotter and I was told by a very respectable yamaha guru it was OK... My motor has never run better.

[misterpeabody5]

it does make me worry, dealing with a $20,000 engine, and I know those Japanese engineers know what they're doing...if I ran higher octane wouldn't it slow the ignition down, eliminating the possiblity of predetonation? I definitely don't want to do any damage to the engine, I'd much rather have fouled plugs than...I will listen for any pinging, and just go from there...

[JUST-IN-TIME]

running higher octanes is a waste!
compression is not that high for it

[misterpeabody5]

I agree that we need only to run the minimum octane that will prevent predetonation, but with a hotter plug, perhaps it could offset the potential damage to pistons, but not sure, just asking...

[slapshot]

I'm running the 8's also. I have been using nothing but 87 octane gas and it goes run much smoother and the plugs last much longer.

[Rich Z]

When I get new batteries in my camera I’ll try to post a pic of BR9s that are over a year old and still running great. Gapped at .39 and injectors cleaned, flow tested and calibrated once a year. I’ve said on here before that most of the problems with plug fouling and excess smoke is from flooding injectors. I’ve also learned years ago what a hotter plug can do.
I like the other gender so please no more winks.

[misterpeabody5]

Rich, I'm pretty sure I'm not even close to a lean condition, I have 4 sets of 9's that I clean and reuse, they always come out slightly fouled. I even fouled a brand new set last week putting the boat on the trailer, goosing the throttle and then letting off, she died right there because of fouled plugs. It was my fault, too much gas and then none...It did restart after some cranking, but I'm gonna give the 8's a try probably Monday and check them out. I'll let you know how goes and I promise not to wink. I don't like it when people wink at me when they say hi, or when they call me "buddy"...

[misterpeabody5]

and by the way, thanks for answering my original question about octane. It seems that the 87 in there should be sufficient and I'll leave that alone until I hear otherwise, as I listen to her burn the liquid gold...