Gear slipping?

[pittsbfan2000]

I have a 89 Johnson GT150, I just had the powerhead rebuilt, first time on the water yesterday with it. I am doing the break in, when I go below 2000 rpm everything is ok, but when i go get on plane then throttle back some, i'll have it around 3500 rpm and after a short time, the boat will slow and almost stop while the rpms are still at 3500. Any ideas on what this could be or what i should look at? I never had this problem prior to the rebuild.

 

[Walker]

Re: Gear slipping?

Prop hub is spun.

 

[pittsbfan2000]

Re: Gear slipping?

What does that mean? Is there something I can look at to determine that? I just installed a brand new prop on yesterday, alone with the hub kit. <br /><br />Thanks for any info you can provide.

 

[Walker]

Re: Gear slipping?

Pull the prop off and on the back side put corresponding witness marks on the inner steel ring and on the edge of the prop. Put the prop back on and try it again. After you get it to slip, then pull the prop and check the marks to see if they are still lined up. If they have moved then youm need the prop re-hubbed