Merc 175 Jet Drive Boat Pulls to left problem

"Hi All,

I have a 97 Sea Ra

"Hi All,

I have a 97 Sea Raydar 16' jet boat with Merc 175 jet drive. Engine rebuilt, works great.

Problem: Despite the nozzle being properly aligned
with the steering cable/wheel, and planing speeds, and ESPECIALLY at half planing, the boat pulls severely yo the left and I must compensate with steering to the right, putting constant strain on the steering cable, which has broke once before.

Shop that rebuilt engine and replaced steering cable (teleflex) could not diagnose the problem.

Seems to track straight at idle.

Pulls left at it's worse at half plane, when stern dragging the deepest (so bad, can't keep her
straight)

Pulls less at full plane but enough requiring a quarter turn of wheel to keep er straight.

The problem started when boat was left in salt water for a few weeks with heavy barnacle growth,
(SC summer water), bottom was cleaned
1- Perhaps uncleaned barnacle growth inside the jet drive causing water flow problem?
2- Jet drive bottom plate seems installed evenly, perhaps just 1/8th of a disbalance would cause this?
3- Problem with rotor or blades in jet drive?

Any ideas and help appreciated, continued strain on the steering cable will cause it to break again, I'm sure.

Charleston Jet Boat"

"Do you have any kind of ride

"Do you have any kind of ride plate that is adjustable under your stator? If so you might check/ measure the distance on both sides to your hull. I know on my boat 2 screw threads up or down on one side will compensate for a big fat guy (increased weight on one side of the boat). If nothing else you might use this as a fix for the boat, just adjust the jet drive bottom plate to push you where you want to be.

Do you have a trim tab either stationary or adjustable? My boat has a 2 inch tab on the entire back of the boat, I can use it to "fine tune" my ride to get on step ASAP in tight water. If one side were bent more it would pull/push me hard.

I dont think #1 or #3 have anything to do with it but if one side of the boat was dragging more than the other because of irregularities in the hull (barnacle pitting) that might do it. Dents from rocks will do it on my boat.

Good luck"

"Russel,

Thanks for the pos

"Russel,

Thanks for the post, there is a ride plate,
it seems straight and even to the eye but I'll measure more closely and play with the adjustments.

I'll also have someone else drive while I hang off the back and look to see if the jet nozzle is pointing straight back properly when the boat is pulling, to determine if jet nozzle/cable adjustment is the problem. Don't think so though, it's on straight and turns evenly lock to lock.





No trim tab plate. Hull is clean."