I had rebuilt my stock nikki about a month ago, and seemed like it was down on power. I was prety busy and didn't have much time to tinker around with it, 3 weeks later after a long drive home from the cottage I lose an apex seal, when i remove the spark plugs they were a very bright white color. The 3 days before the engine failure, had been mostly highway driving. I thought nikkis run rich at high RPMs. I'm getting a used engine in 2 days, and i'm wondering what i should do to richen the mixture a bit. so i don't screw up another one. I have headers to a magnaflow, and DLIDFIS. I shouldn't have to change jets yet right? Any thoughts?

Thanks, Matt

 

Non turbo? As long as you don't overheat it, no.

You were probably running lean because your fuel system is garbage. If you have a stock fuel pump, your fuel system is garbage.

Running lean most likely did not kill your engine, though. I've run WOT for hours (well, okay, 90 minutes or so) running so lean that an O2 sensor reads straight zero volts. No problems, other than running hot, but that's what heater cores and manual fan switches are for.

 

Don't mean to hijack... but what about running too rich? I know I've been running rich for about a month now, and I'm just about to get it fixed. I'm planning to do a full tune up and MMO/power foam treatment right after. The 2.5 month old plugs are pitch black... will there be any permanent damage of any kind due to having had it too rich?

 

nah. Maybe an accumulation of carbon in the combustion chamber, but nothing a good cleanup treatment cannot handle.

How did the cat work out btw?

/hijack

 

well, I finally put it in last week, but the car is still running way too rich so it aint passing emissions yet. I finally gave up and brought it to the mechanic. the cat seems to be doing its job though.

 

I did once pop an SE engine (with a dellorto) on the highway cruising at 3500 RPM with a "to lean" Dellorto.

It did crack the porcelin on my spark plug too.