New 150 4-stroke Questions

[Psalm 99]

Engine is a Yamaha 150 XB with just over 50 hrs on it. I broke it in per Owner's manual and changed upper & lower unit oil after 10 hrs. Engine runs beautifully. I've ordered a full service manual from Yamaha which will take a week to get here. Going out this week and would like to address a few issues: (1) Idle speed dropped from factory set @ 700 rpm to 600 rpm (on muffs) after last time out. Engine idle normally is about 600 rpm when boat is in the water but has always been at 700 on muffs which is understandable. Is the drop in rpm at idle indicative of a potential problem and how do I set it back up? (2) After last time out and with boat out of water, and gear shift in neutral, prop wouldn't spin by hand in clockwise direction and roughly in the other. Moving the shift lever back and forth didn't help. Engine started right up on muffs and prop didn't spin in neutral. Prop spun cleanly by hand once engine was shut down and in neutral, problem seems to have gone away. Do I have a problem or is this normal? Sure appreciate any suggestions.

[robert graham]

Maybe you're over-thinking/worrying.....go out and enjoy your motor...

[99yam40]

Do not start jacking with stuff on a new motor.
If it has a problem take it in to where you bought it.
you do not want to mess up the warranty

Warranty will take care of most everything but bad fuel problems

[pstephens46]

You don’t know the actual rpm until the motor is hooked up to a computer. My tach read 600. YDIS showed 698. Beats me. Who cares? Run it. It’s fine. Just don’t hit any lava chunks!

[pstephens46]

Curious about the fishing around the islands there. What do you target? That water gets deep real quick. Could get rough too.

[Psalm 99]

Thanks guys, had a rough time with my old engine and want to get it right with the new Yamaha. Fishing off the 'Big Island' is quite a bit different than it was off the Calif. coast. About half the time, we fish pretty much inshore, between 180' - 240' which is best for Ono (Wahoo) but also pretty good for Mahi Mahi and small tuna (Kava Kava and Aku (Skipjack)). There are a number of FADs (buoys) along the Kona Coast placed in about 6,000' and deeper. These are great for Mahi and big tuna (Ahi or Yellowfin). Lot of the boats go after Marlin in the deeper water. Quite a few bottom fishermen also as the restaurants cater to some of the fairly exotic varieties like Onaga which I've been told inhabit depths around 900' and are pretty big. The wind can come up pretty fast and the channels between islands are downright scary at times. Off the Calif. coast, if my engine failed the evening westerly would simply blow my boat to shore. Here, you may be heading for a slow trip to Japan so you see a lot of twin engine or kickers on boats. Its a lot rougher normally over on the Hilo (NE) side of the island as this side faces both the trades and incoming seas. I've never launched on the Hilo side although they have a good harbor and launch facilities. Kona is a great place to launch but can be a little crowded. There are only two launch facilities north of Kona and the main one often silts up during the winter storms. That said, on the Island's lee (SW) shore you can often find a gentle breeze, small swell, neat shirt-sleeve weather, warm water and even a few fish (I was skunked last week).