Be sure to run a high quality fuel treatment designed to clean carbon deposits from the valves, injectors, combustion chamber, etc. in the fuel. I added treatment to my tank EVERY TIME I fueled up for about six weeks. I usually pumped between ten & fifteen gallons depending on the specific instructions on whichever brand treatment I was using that particular time.
I probably went a little over-board but it certainly didn't hurt. If you can get it & are willing to spend the $$ I would HIGHLY recommend YAMALUBE RINGFREE. You run the SHOCK-TREATMENT dose with a full tank & once will do it, twice to be extra sure because of how tight/narrow the gap between the plug & cylinder head.
Take your time, don't get in a hurry. VERY IMPORTANT: Be sure to change your oil & filter when the job is finished! ESPECIALLY if you use RINGFREE. There will be gunk in the oil that shouldn't be left churning through the motor. Because I let the motor sit over night with the DEEP-Creep inside the cylinders it all seeped past the poistons right down into the oil pan.
I didn't even crank the motor until I dropped the oil. I let it drain while installing the new plugs & re-assembling everything. I used a cheaper brand full synthetic (Super-Tech) because I'm going to change the oil once more in about 3,000 miles to ensure it's totally clean. I'm a bit on the OCD side when it comes to my Expy...and a lot of other things now that I think about it
Good luck!
