how long do your sparkplugs last

[pnut]

I have an 04 hpdi 250 and the last set of plugs only lasted about six hours at differing rpm's.Is this normal?I had a problem earlier where I only fouled the same two plugs.After repeated trips to my dealer they told me my starting battery was bad.They installed a new battery and this time all the plugs were dirty instead of just the two it was fouling.Before the other 4 plugs were pretty clean.Any ideas?I also jad a mechanic tell me the only sure way to adjust the oil pump was to measure the output of the pump not the clearance.

[looking4five]

Has your engine had the oil pump replaced under recall? I know they recalled a bunch of them a while back.

I replace my plugs about once a year. Not because there is anything wrong with them, just preventive maintenance.

[slapshot]

Since I stopped using Yamalube, they now last all year (about 75 hrs). They are still clean when I do my annual maintenance, but I replace them anyway.

I remember hearing about the HPDI oil pump issues. That should help.

[inthebox30lbs]

Same thing here on the yamalube, i usally check my plugs and change them every five months, I run my boat quite a bit and with the yamalube they were all fouled up, and actually ran into a fouled plug last summer 10 miles from the ramp. Ran seafoam in every tank still didnt matter. Switched to penn full syn. and the plugs seem to last twice as long, I just looked at them this week after on the water 2-3 days a week since the end of January and they were twice as clean, and did not need to be changed. I bet I could go 100 hrs easy with a set of plugs now based upon what they looked like when I checked them this week. This is a 07 vmax carb too.
scott

[pnut]

I have the latest oil pump,they installed it when they put my new power head on as the old one came apart

[PolarKraft195]

I've been using 100% synthetic oil (Amsoil) for the last 8-10 yrs, along with Seafoam in EVERY gallon of gas put into my outboards.

I've been changing my plugs every 2 yrs!

And to be honest.....only for the hek of it! They still look VERY clean and I never have had any performance issues. I put between 50-60 hrs of use yearly on them.

By using synthetic oil along with Seafoam, the internal parts of the engine along with the plugs are super clean.
I always do a little "probe" check with a small probe flashlight to check out the pistons/piston walls inside the sparkplug holes every now & then, and you would not believe how clean it stays in there