Sea Rayder F16 tries to go left while on plane

[KStro]

Yes, the question is wether the seven vanes seen from the nozzle side in the earlier set of pictures are intact or damaged at the leading edges (facing the impeller outlet). I don't think the center screw should have to be touched; it may hold the impeller to the shaft. Check if it rotates with the shaft. The complete housing aft of the impeller should come out as a unit.

Yes, you are right. The whole thing came off as a unit. I was surprised to find oil in there. Obviously I will have to replace that oil. Do you know what kind of oil it is?
Here are the pics? it appears to look good everywhere to me. Nothing appears damaged or excessively worn.

 

[KStro]

I forgot to post a pic of the sleeve that goes around the impeller. Not sure if it is important, but here it is in case.
It is odd that I have read of others with this issue after having some work done professiionally with all new parts. Because of that I was looking for something that might be able to be assembled backwards. But it appears to mostly only go one way. The only thing I saw was this sleeve probably could go in 180 out. The only thing I see different is the width of the lip where it mates is longer on one side that the other. I don't know if that would have any effect on it.

 

[baeckmo]

Ok, if you look at pic 3, there are "streaks" of erosion at the outer surface, starting from the vane leading edges to the left. That erosion is missing on the other vanes, and shows that the fluid leaving the impeller has a higher (too high) rotation in the sector between about 6 o'clock to 11 o'clock. You also see cavitation erosion on the vane surfaces, particularly the one at 9 o'clock. The vanes can not straighten that part of the flow, so it leaves the stator with a bias to port, resulting in the left turn.

Unfortunately pic no 2 and 4 are unfocused, so I can't "interpret" the signs there. Anyway, this is enough info to confirm my preliminary view; there is a disturbance in the inlet, but in addition I must say the stator casting quality is not good. Those surfaces see the highest velocities in the whole unit and should be smooth, and the leading edges of the vanes should be nicely rounded without nicks or sharp marks. I'd be surprized if there isn't a 9- or 11- vane aftermarket piece available. I'll check the earlier pics from the inlet and scratch my head for a while before giving a final recommendation. As for the oil, use standard outboard gear oil.

 

[baeckmo]

Oops, you sent the additional image while I was thinking..(slowly...). There are some serious scuffings on the liner, indicating that the oil lubricated impeller bearing is out of round. Might be good idea to check impeller radial play as well.

 

[KStro]

Oops, you sent the additional image while I was thinking..(slowly...). There are some serious scuffings on the liner, indicating that the oil lubricated impeller bearing is out of round. Might be good idea to check impeller radial play as well.

I didn't notice much play trying to move the shaft in any direction as it is. It moves a tiny bit at the outboard end, but I would think it is just a little because the stator is removed and that bearing in the back is not currently holding that end of the shaft in place like it would be if assembled. I didn't notice any movement at the engine end of the shaft.
I believe that bearing inside the stator veins is what you are saying may be out of round. Do you think that is causing the cavitation issue you mentioned, in turn causing the pull to the left? Do you think replacing that bearing would correct it? Any other suggestions? (or still head scratching...lol?)

 

[baeckmo]

.... gone fishin'! Oh, and at my age the scratching takes some time..... first I must remember why I'm doing it...! Besides, now all "veterans" in our island community have got our final anti-covid treatment, so for a couple of weeks there has been an intense buzzing all over the archipelago from grandkids we haven't seen for a year now. Teaching them to hook the mackerel and diving for crabs has had top priority these days!

But to your jet: Can't see that the bearing has anything to do with the steering issue, just check that the impeller cannot touch the liner when you collect the pieces again. I have been trying to figure out what the geometry of the intake really looks like; there are sharp edges and narrow slots that really don't belong there, so I'm trying to find better images showing the region before I say something stupid.

One way to treat the problem might be to fit a vertical straightening vane at the outlet of the fixed nozzle, but that is just a medicine to hide the symtoms, it's not a cure for the sickness. And there is a risk that you will lose some performance, so please have a little more patience until I have "seen the light".

Edit: Btw, the second pic above (inside of the "bowl") shows some interesting marks, but it is unfocused, could you take another image before reinstalling the bits?

 

[baeckmo]

A thought..... the grommet around the base plate looks slightly "moth-eaten"; could it be that it is leaking exhaust into the inlet? I would test to fill out the opening with an elastic compound, like Sikaflex 295 or similar. That would make it possible to get a smooth transition from hull into the inlet.

Found a picture of a Sportjet inlet, see attached. Is that the type you have?

 

[KStro]

I get the fishing and grandkid time. Glad some of that is coming back to normal. That pic you found does look like the intake on the boat. I tried to take a few better pics (attached).

 

[Lordneeko]

I just wanted to chime in and say I'm really enjoying reading this. I bought a used 16fxr this summer and it has a pull to the left on plane as well, even more so the more loaded the boat is... balancing helps it a bit, but still it is there.
I'm glad to see this is a 'current' discussion and not 10 years old.
I'll go back to stalking now.

Also, I have a issue that turning right makes the boat seem to want to cavitate and fight me, but turning left is nice and smooth. I've always assumed it was because I had more weight on that side...but I'm wondering if it is related now.

Back to 'watching'.

 

[KStro]

I just wanted to chime in and say I'm really enjoying reading this. I bought a used 16fxr this summer and it has a pull to the left on plane as well, even more so the more loaded the boat is... balancing helps it a bit, but still it is there.
I'm glad to see this is a 'current' discussion and not 10 years old.
I'll go back to stalking now.

Also, I have a issue that turning right makes the boat seem to want to cavitate and fight me, but turning left is nice and smooth. I've always assumed it was because I had more weight on that side...but I'm wondering if it is related now.

Back to 'watching'.

I get what you are saying. I first thought it was weight distribution also. I moved the battery more left and added a second battery over there (since I wanted a backup anyway). Then I tested it shifting weight around the boat. It did seem to help a little if I put a lot of weight on the left. But I had enough to where when the boat was just stopped I could see it left side heavy just floating. But it still pulled left at speed. However, I found that on deceleration it pulls to which ever way has less weight. So even pulling to the left at speed, it would pull hard right when I slowed down quickly when I had it left side was heavy. That made me think that the left pull at speed was a different problem and over weighing the left side was just masking it a little.

 

[KStro]

If I get it corrected I will post the result here. I see a lot of people having this problem, but as of yet, I haven't seen anyone posting a resolution. Just what didn't work.

 

[KStro]

I found something that seems like an issue to me. Where the jet nozzle connects to the steering nozzle, there are two allen screws, one on top and one on the bottom that the nozzle pivots on to allow steering. I noticed that on the top there is a plastic bushing that goes around the allen screw, but on the bottom there isn't one and it feels like there is a lot of slop there. I think there is supposed to be one and it is gone. I am wondering if that could allow the nozzle to move off center and cause a pull. Maybe our stalker could look at his and see if he has a similar issue. In any case, I am going to try to replace it or work on a way to eliminate the sloppy movement in the nozzle. You can see in the pic of the bottom a significant gap between the allen screw and the nozzle mounting hole. The pic of the top with the bushing looks tight.

Let me know what you guys think. Thanks!

 

[Lordneeko]

Here is what mine look like.

 

[KStro]

Here is what mine look like.

Yours looks good to me. It has a hex instead of an allen, but the bushing looks intact. I am thinking that it is not the problem for me either. It was A problem, but probably not the issue causing the left pull. I won't know for sure until I test it.

The actual bushing is of course, not available. I got a bronze bushing/bearing that was slightly too small for the inside diameter and big for the outside diameter. Using a rotozip and a rat tail file, I got the outside diameter just small enough to pound it in the nozzle and the inside diameter small enough that it moves freely on on the allen screw, but with no slop. I reassembled it all over the last few days. If the weather allows, I will probably give it a test run tomorrow and see if there is any change.

 

[KStro]

Took it out for a test drive, but no change of any kind. Still acts the exact same way. I tried to take a pic of the wake (attached) while I was driving. You can see that it is not just the wheel turned right. The jet spray is certainly shooting to the right while the boat is moving straight forward. If I adjust the wheel so the jet stream is straight the boat make a pretty hard left.