Motor issues

[BRS]

I have a 225 Johnson. 21 ft stratos and I have started having some issues getting on plane. When I give it gas the nose comes up RPMS hit about 2500 and stay... If the guy in passenger seat heads toward the front of the boat the nose will fall ill hit plane and the boat runs great... I have been trying to adjust the jack plate to get the most out of the motor and it had ran great the last few times I took it out with this setup. Even ran great on take off last week but after first fish full live wells it started acting up

Does any one know what would cause this or suggestions on what to do?
Thanks in advance!!

I had a situation with a 21 foot Stratos similar to what you're talking about I think. I would go to take off and boat would not come up on plane unless I moved wait to the front. Took it to a dealership to let him check out the jack plate and to make sure all adjustments were right. He told me everything looked good nothing wrong with the boat. So we took it down to the lake and when he would go to take off everything worked perfect. What I had to do was when taken off hold throttle all the way and at the same time trim the motor up when taking off to get up on plane. Cost me 50 but best 50 I believe I ever spent. Only boat I ever had that I had to do like that to get up on plane. You might have already tried this but if not would give it a try and see what happens.

[shakey head]

Thanks for all the replys…. I usually do start trimming the motor up as the nose starts to fall I always have but it doesn't want to start to fall.... But I'm taking the boat out this weekend and I'll try to trim it earlier and see what happens....

Also sorry it's took longer then I thought but I got the measurement of 3.25 for pad to prop that is close to the measurement that was suggested

[kstonich]

Ok so it ran fine for five or six trips. I think that's where we start. By shifting weight and motor height you are probably masking the real problem by reducing the power necessary to get up on plane.
You shouldn't have to alter how you were driving it to get on plane again hat just shows you that its probably engine related. I to had powerpac issues on a 150 Merc. Had them replaced and what a difference. What was interesting is that the motor was smooth no missing just loss of power under heavy load. Unless you find hat for some reason the trim has shifted dramatically I would take it in to a service tech and have the engine checked. My Mercury cost me 450$ about 15 yrs ago but was well worth it .