Re: Difference between 135 & 150 HP Mercury
I don't know a lot about the later 2.0L motors but for the earlier (pre 91 or 92) 2.0L motors the difference is carbs and probably tuner, but not totally sure the tuner is different. Anyway you should be able to find a used 200 tuner pretty cheap and try to find a set of 175 carbs. The carb number will be wh-34. There are probably other carbs that will work too. Don't expect the performance difference to be that great, but you should gain a few rpms on top end. Basically if you want more power from the 2 liter you gotta spin'em faster. I know of people that swap the front half and intake from a 200 and spin'em north of 6500, but for the trouble and money I think it would be easier to sell the 135 powerhead and put a 175 or 200 (2.4 liter) in its place. The best part about that is you still have 135 mid/serial number for insurance purposes.
