For the last few weeks I was convinced that I had blown a seal on my engine. The engine and car would shake like a paint shaker, and the idle was barley enough to keep the car running. It would backfire randomly and sounded like one rotor wasn’t firing. I was exhibiting the signs of a blown seal and had made an appointment to take the car in for a compression test.

I was curious if it could be something else because all these symptoms started in my driveway after I backed the car out of spending the winter in the garage. I tested all fuel and spark possibilities I could think of, but nothing worked. I probably checked the Map sensor like 100 times. I didn’t think to pull the plugs because they were supposed to have been changed last fall when I took the FD in for a tune up – they were not.

The leading plugs were so full of carbon, they were struggling to fire. 20 min and 4 new plugs later, the car runs as good and as smooth as ever!

 

Cheapest engine rebuild ever.

 

i need to change mine, but damn im lazy when not at work.

 

Stay at work LOL

 

My car was running fine, but I hadn't changed the plugs since I got the car 6 months ago, and I had put on almost 5K miles, so I thought it was about time to change my plugs. Looks like it wasn't a bad idea...

 

Yeah, just changed mine last week. All 4 were carboned up. The whole tip was black lol

Car sorta feels the same except more smoothness up top but i feel better knowing i changed them since its been a year already.

PS: I think its better changing them from up top. I been changing my plugs from the bottom since the beginning and thought i try from the top. Well it was wayy easy doing it that way except for the front trailing plug which is sorta blocked by hoses, other than that, it was easy.

 

Yea, I read a bunch of pepole saying to do it from the bottom, but I took off the intake elbow, and the rest was a breeze. 1QWIK7, did you take off the intake elbow too?

 

Oh, I forgot, Here are the pics of both leading plugs. Its no wonder why my engne had a hard time running with that much carbon on the plugs.

 

Wow...thats hella carbon build up! And the electrode is pretty much gone. Don't think it would of been good if a large chunk of that carbon broke off in the motor. I could imagine a night and day difference with the new plugs.

 

Yeah you def have to take off the intake elbow to have any hand/tool space to get to those plugs. Some people go crazy and take off other things but i didnt see it was necessary.

There is a hose or 2 that blocks the front rotor's plugs. I traced one hose and it goes to the PS resevoir? I may be wrong but i didnt want to force my ratchet too much cause thats the last thing i need, is a busted hose pertaining to something like that. So i just had to be careful.

All in all, doing it from top is def the best way IMHO.

 

i suppose coming from the top works but, it is so easy to get the plugs out from the botom. It takes longer to jack up the car than get the plugs out when coming from underneath.

 

I don't get how you guys have to take stuff off to get at the plugs. 15 minutes and a plug socket+ratchet wrench and I've got em all done, no need to remove anything. Then again, maybe its just because im really flexible haha.

 

Yeah true but different people do it different ways.

I find it easier now to do it from top. This way, im not in a uncomfortable position, i can take my time and not go crazy looking for stuff while im on my back and i can see better. Plus you have more leverage if a plug is a bit tight or if you're using a torque wrench (since torque wrenches are a bit longer than normal ratchets), you just have more room.

Idk, out of all the times i've done it lying on my back doing it from the bottom, doing it from the top makes me wish i always did it from the top.

 

Carbon is conductive, so if everything is heavily coated (as your plugs are) the carbon can shunt the current to ground without ever actually sparking. Hence the misfire.

 

how often you any of you change your plugs..... I changed mine when i first for it and it's got about 4000 miles more on it..... and considering changing them, I have a weird idle thing going on... and I have a lot of oil that goes into the engine coming from the turbo

 

I just changed mine. It was like a gift from God. My mileage is back up too.

 

that didn't answer my question though.... lol

I mean how many miles

 

I change mine at the begining of every season and every 5000km or 3000miles later. I run a gt35r single though. When I ran my twins I did it at the begining of every season and then 7500km. I usually only get around 5-7000km in a year dues to our long winters up here.

R.K.

 

Depending on how you drive, what mods you have, what plugs you're using etc etc.

Most people using the stock 7/9s change them every 10-15k?? I know i heard some of them do. Or some of them change them once a year regardless of miles. There are even some hardcore people that change them every oil change. But then again they run big singles so.

I think once a year seems about normal. They are only couple of bucks each and takes 30 min to do the entire job.

 

Some of these posts baffle me. I know there are many variables to peoples build that determine how often to change plugs. But, I would have to think that anyone running more fuel with any porting,even on stock twins, should be changing their plugs every 2000 miles with the oil. I understand it depends on the driving too. But, For the most part, it's a small price and short time for knowing you motor is at it's best in care.