Sould have cleaned hull first?

[sburner]

Have a 20' seaway with a 150 johnson. Boat stays in water. I was only getting 4800 wot with a 15'd-15'p prop. I had some props layin around so I put on a 15d 13p and i got 5200 but lost a lot of speed and it didn't sound or feel right. I noticed the bottom was dirty and had some barnacles. I took it out and cleaned it . I then put on a 15d 17p and i now get 4800 at wot but I gained alot of speed at less rpms. The motor sounds and feels great and I only run it at about 3800 -4000. Is it o.k. to stay with the 17 or should I go back to the 15-15. It runs better now then it did with the 15-15 even when i put it in in the spring.

 

[steelespike]

Re: Sould have cleaned hull first?

The motors hp is rated at 5,000.I think you should go to the 15.The motor should be able to reach its rpm range or it may be lugging, possibly causing engine problems as time goes by.

 

[rndn]

Re: Sould have cleaned hull first?

Prop your outboard so it can get as close as possible to the maximum suggested rpm's. Your engine will show it's appreciation by providing you with years on enjoyment. Lugging an engine is really bad for it. Picture trying to ride a 10 speed bike up a steep hill while staying in 10th gear.