350 mpi rev. problem

vip215dl

vip215dl

Cadet
Joined
May 9, 2010
Messages
26
I have a 1998 vip deck boat with a 350 mpi. The last time i took the boat out, it wouldn't rev past 3200 rpm. but was running around 45 mph. It acts like it's hitting the rev. limiter, so i back off the throttle to where it doesn't hit the rev. limiter. Boat runs perfect up to that rpm. It doesn't backfire or miss or anything. I did go from a 21p x14.5 prop to a 19px15 prop, but you would think that it would still go on up to 4200 or so. Also, i took the throttle control off to work on the trim switch, but not sure if that had anything to do with it. Any advise would be appreciated. thanks
 
C

CharlieB

Vice Admiral
Joined
Apr 10, 2007
Messages
5,617
Re: 350 mpi rev. problem

Suspect the tach, you may be hitting the Rev Limiter with the smaller pitch prop.

Beg, borrow, or buy an inductive tach and retest.
 
vip215dl

vip215dl

Cadet
Joined
May 9, 2010
Messages
26
Re: 350 mpi rev. problem

does the speed sound right at that rpm? I can't remember, but i want to say with the other prop, it would run in the mid 50's. I guess i could put the other prop on just to make sure..
 
havasuboatman

havasuboatman

Ensign
Joined
Mar 5, 2009
Messages
904
Re: 350 mpi rev. problem

vip215dl said:
does the speed sound right at that rpm? I can't remember, but i want to say with the other prop, it would run in the mid 50's. I guess i could put the other prop on just to make sure..
Click to expand...

There you go. If you change something and it has an adverse effect on the performance, first thing you want to do is change it back.
Changing your prop is like changing the diameter of your car's tires. It makes a difference.
 
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