Yamaha AR190 Transom Removal

[swatski]

Out of the hole it's perfectly fine, just can't get above 15 mph
I'm going to double check the caulk,,,, which is the best I should be using? Should I remove it completely and then re-caulk or just patch?
You may have this covered in the link you sent me but again I'm still at work and cannot do that until tonight

What are you rpm at WOT?
(Max rpm)

You should be over 7,000 rpm, ideally close to 7,700-7,800 with little or no cavitation on the hole shot (which you appear to have).

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[Fred8158]

6-7000 rpm what i can remember...no higher

 

[swatski]

6-7000 rpm what i can remember...no higher

Given you are not at high altitude that’s too low - way off the mark.
Old spark plugs, dirty oil filer (overfilled oil?), throttle cable not hitting the APS stop (accelerator position sensor - the little wheel in the engine bay bulkhead not turning all the way to hit the stop - simple cable adjustment) - those would be some first line considerations. Impeller pitch is unlikely to be an issue if you were getting higher rpm in the past. I’m sure there is more.

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[Fred8158]

Everything you mentioned has been checked and were replaced
Only other variable that I had mentioned earlier is that when I am alone in the boat I can do a higher speed, probably 30 mph

 

[swatski]

IDK. Dirty hull can drag the top speed down 10-15mph easily, maybe more if you growing barnacles, lol.
I would also check the main bearing - by pulling the cone off.
(Don’t pinch the o-ring when you put it back.)

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