Hello. I have been burning my brains on a problem of my 90 Hp V4 Johnson. the problem is that when i'm running at cruise speed 4000 or 4500 RPM it will run perfect, and then it would drop 500 RPM and sound as if it were running on 3 cylinders. it does this for less than a minute (not always the same interval) and then it composes, and i feel the thrust from the regained power. and after 5 mins it will do it again. it does not have a regular pattern, sometimes it does it, sometimes it does not. I don't know if it is fuel or spark, and a mech. charged me like $200 to "fix" what he called a "collector" over the cylinder (I think a pair) but it seems nothing happened. It is possible this mech did not fix it well, just makeup.<br /><br />anyone has anyh help on this I will gratly appreciate it.<br />thanks in advance guys.
