I have a 1991 Suzuki DT225 with 830hrs on a 1850 Magnum ski boat.My problem is that it keeps fouling the plugs after aprox 2 hrs.When i first got it,it was fine for about 15 to 20hrs then started missing and would'nt go over 4000 rpm. It has no power to pull a skier out of the water, (not a good look for a ski boat).It then won't go over 4000rpm.I have looked at the plugs and they are wet but hot too carboned up.I noticed that it was running hotter plugs than is recomended so put the correct plugs in and the problem was fixed for about 2 hrs than it starts missing and loses power again.I found out that the previous owner was having the same problem and running the hot plugs fixed it for him, but this dos'nt seem to be the case for me. I have also noticed that when running at 3000rpm it will creep up to 3500 rpm then back to 3000rpm.The local boat shop has had a look at it and the thermosates ,oil flow seem to be ok. Any ideas would be helpful.
