question about 2001 90hp mercury 2 stroke

I bought a boat with a 2001 90hp mercury 2 stroke on friday. I put the boat in today to take it for a ride, when I started it up the motor sounded perfect but when I put it in gear the motor seemed to run rough and got alot noiser when idling. I bought the boat a motor from the original owner and he only used it 2 weeks a year when he went to canada, the boat a motor look brand new. He also told me that if there were any problems at all I should call him asap. Before I call him I thought I would ask the guys of IDO first to see if this sound and rough idling are normal. The motor I owned before this was a older johnson 40 and it always ran rough and made lots of loud noise

Did the motor smooth out and run better for you when you got up on plane?

Are you using old gas? Did the original owner treat the gas before storing it? Do you know when he last used it? Just a few questions that might help us, help you.

FDR

yes, the motor smooths out when over 1100 rpms and sounds good. only at an idle does it sound noisy and idle rough. The previous owner said he always ran seafoam in it. I just filled her up today, she only had about an 1/8 tank of gas.

I have the same motor and it does the same thing. It is really cold blooded (even when its hot out). I found out that if I let it idle while I park my truck, it runs well. I is rough at low RPM’s but is really quite a smooth runner at higher RPM’s. Good luck.

thanks for the help guys!

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I have the same motor and it does the same thing. It is really cold blooded (even when its hot out). I found out that if I let it idle while I park my truck, it runs well. I is rough at low RPM’s but is really quite a smooth runner at higher RPM’s. Good luck.

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I have the same motor and mine doesn’t like hot weather. It idles and runs better in January than it does in July—and yes I know that for a fact

just got my boat back from the shop and runs like a million bucks, they adjusted the carbs and the bill was only $82 bucks.

I too have the same 2001 motor and since I bought it 5 years ago it has always ran the same as what you and the others described. Does it idle alot smoother now after carb adjustments?

runs great. smooth. still a 2 stroke but smooth. the mechanic at the shop told me that merc 90’s of 2001 were the best motor merc ever made.