RPM drops when I Adjust trim or tilt

[forgetaboutit]

When i'm at WOT and adjust trim or tilt the Rpm drops why?. Thank for any help i can get

 

[dms]

Re: RPM drops when I Adjust trim or tilt

I believe it's because you're essentially changing the "pitch" on your prop. The same reason your rpm lowers when you go to a higher pitch prop.

 

[Boatist]

Re: RPM drops when I Adjust trim or tilt

forgetaboutit<br />It is normal for rpm to change any time you trim boat. When you trim the motor in the bow will go down. That means more wetted surface, slower speeds and lower rpm. When you trim out the bow will go up, less wetted and higher rpms until get out far enough that prop angle is not at 90 degree to water then again speed will drop and again and rpm will go down. If trim out too far rpm will go way up and boat speed will drop as prop cavitates.

 

[Boatist]

Re: RPM drops when I Adjust trim or tilt

forgetaboutit<br />It is normal for rpm to change any time you trim boat. When you trim the motor in the bow will go down. That means more wetted surface, slower speeds and lower rpm. When you trim out the bow will go up, less wetted and higher rpms until get out far enough that prop angle is not at 90 degree to water then again speed will drop and again and rpm will go down. If trim out too far rpm will go way up and boat speed will drop as prop cavitates.

 

[nnosker]

Re: RPM drops when I Adjust trim or tilt

Thats what makes it more fun, the less you see the faster you go. The more you see, gives you more time to enjoy the scenery.

 

[clanton]

Re: RPM drops when I Adjust trim or tilt

when you are on plane trimed and running smooth, if you engage trin up for a second and the rpms drop 2/400 rpms, check stator output to powerpack. Engine may run rough for a few seconds.<br />There is old OMC service bulliten about this for 35 amp stators.<br /><br />Edited 6:30<br />Other post said engine surging. Time for compression check. Check magnets in flywheel, ignition systen check, Fuel pressure and vacumn.