JBP Lateral Thruster MOD - Feedback PLZ

[Brian Millette]

First the good. I still think the thrusters are a great idea and I was very happy that JetBoatPilot got with me on the weekend to try to help me.

Now the not so good. I don't think (in my humble opinion) that the engineering is so good. The bolts for the thruster have a nylon lock to insure that they don't back out.
Not a bad idea even though the original bolt didn't even have lock-tite. Problem is the nylon is a bit thick and very hard.

Like PeterB, I was advised to tap the threads first. Problem is, a new M8 bolt went in with no problems. To tap a perfectly good thread is to slightly increase the size. That is why the new bolt will then fit. Problem is that the remaining threads don't grip as much surface as the original ones and the entire installation is less strong. Admittedly this is a very small amount but, for me, it's the principal of proper engineering. Additionally, it's very hard to tourqe the bolt to 10 ft lbs as instructed when it takes 20 to 30 ft lbs to insert it in the first place.

I intend to do the following; run a die over the new bolts to cut through some of the nylon, then use lock-tite red for installation. But because the bolt is almost 5 mm longer that it has to be, I will not apply it to the ends.

As for the gap between the support and the thruster (about 3/8" as shown in the attached photo) and the misalignment of the bolt (tilted aft and not even long enough to put on the nut) I was advised to loosen everything to get everything started then tighten them to make it fit. I really hope my engines weren't built with that philosophy. Simple geometery and common sense says that causing the support to be bent will actually put pressure on the thruster rather than support it to prevent pressure on the mountinting bolt and casting of the thruster. And the two suports are necessarily diffeferent. I believe that slightly bowing the support will cause it to come into alignment, but will post pictures of before and after when I get them to fit.

The only problem I have is that I'm in the Northeast and the weather is not co-operating for working on this.

I still want to say that I think that JetBoatPilot had a great idea (I can't wait to try these out) but I would guess they farmed out the engineering and shouldn't shoulder all the blame. But if you want to mount this with the standards that I have used in rebuilding engines and maintaining various other machinery for years, then buy this item but be prepared to tinker. I haven't even used them but think it will be worth it.

 

[JetBoatPilot]

Thanks for the feedback. I want to make sure the bends are just right for the next batch of parts coming in. We will verify fit on a current bracket and see to it the bends are modified from the supplier.

As for the torque, I did not put a torque wrench on mine (used a previous recommendation which apparently was wrong) when installing but have had no issues with the nylon patch. I will see if I can get an accurate torque value for the installation next time I do one. We still advise lock-tite during the install, even using the nylon patch, but when you're dealing with the masses you have to plan for people to forget the lock tite, that is why the patch is there.

We're looking forward to hearing your feedback after testing!

 

[fireflymedic]

Have them like them. Did a review on jbp's web site.

 

[jcyamaharider]

First the good. I still think the thrusters are a great idea and I was very happy that JetBoatPilot got with me on the weekend to try to help me.

Now the not so good. I don't think (in my humble opinion) that the engineering is so good. The bolts for the thruster have a nylon lock to insure that they don't back out.
Not a bad idea even though the original bolt didn't even have lock-tite. Problem is the nylon is a bit thick and very hard.

Like PeterB, I was advised to tap the threads first. Problem is, a new M8 bolt went in with no problems. To tap a perfectly good thread is to slightly increase the size. That is why the new bolt will then fit. Problem is that the remaining threads don't grip as much surface as the original ones and the entire installation is less strong. Admittedly this is a very small amount but, for me, it's the principal of proper engineering. Additionally, it's very hard to tourqe the bolt to 10 ft lbs as instructed when it takes 20 to 30 ft lbs to insert it in the first place.

I intend to do the following; run a die over the new bolts to cut through some of the nylon, then use lock-tite red for installation. But because the bolt is almost 5 mm longer that it has to be, I will not apply it to the ends.

As for the gap between the support and the thruster (about 3/8" as shown in the attached photo) and the misalignment of the bolt (tilted aft and not even long enough to put on the nut) I was advised to loosen everything to get everything started then tighten them to make it fit. I really hope my engines weren't built with that philosophy. Simple geometery and common sense says that causing the support to be bent will actually put pressure on the thruster rather than support it to prevent pressure on the mountinting bolt and casting of the thruster. And the two suports are necessarily diffeferent. I believe that slightly bowing the support will cause it to come into alignment, but will post pictures of before and after when I get them to fit.

The only problem I have is that I'm in the Northeast and the weather is not co-operating for working on this.

I still want to say that I think that JetBoatPilot had a great idea (I can't wait to try these out) but I would guess they farmed out the engineering and shouldn't shoulder all the blame. But if you want to mount this with the standards that I have used in rebuilding engines and maintaining various other machinery for years, then buy this item but be prepared to tinker. I haven't even used them but think it will be worth it.

So with your explanation of a tap wouldn't a die make the threads on the bolt more loose also? 6 one way, half a dozen the other..........

 

[Neutron]

While i did have an initial alignment problem with the side bracket. I had no issue at all with the center bolt provided. It screwed up by hand then with ratchet using very little effort till I torqued it.

 

[Cobra Jet Steering LLC]

@jcyamaharider
At the risk of being attacked I have many years of experience dealing with customers installing a bolt in the bottom of the nozzle to attach steering parts and I will tell you what I tell them.
If that single position is not done correctly and the bolt falls out the customer will snap off the nozzle when they put the controls in reverse, the way you know it was the bolt is simple.
The top of the nozzle that pivots around the bolt breaks away and allows the nozzle to pivot up with sufficient force to snap off the top of the nozzle since the bottom bolt is missing and the reverse gate is creating a lot of stress on the nozzle as it redirects the thrust downward . Look at the mounting positions for the nozzle and note the top is broken off while the bottom is still intact This is what happens if a bolt falls out of the bottom of the nozzle !

 

[jcyamaharider]

@jcyamaharider
At the risk of being attacked I have many years of experience dealing with customers installing a bolt in the bottom of the nozzle to attach steering parts and I will tell you what I tell them.
If that single position is not done correctly and the bolt falls out the customer will snap off the nozzle when they put the controls in reverse, the way you know it was the bolt is simple.
The top of the nozzle that pivots around the bolt breaks away and allows the nozzle to pivot up with sufficient force to snap off the top of the nozzle since the bottom bolt is missing and the reverse gate is creating a lot of stress on the nozzle as it redirects the thrust downward . Look at the mounting positions for the nozzle and note the top is broken off while the bottom is still intact This is what happens if a bolt falls out of the bottom of the nozzle !

I was kind of pointing out that his comment about a tap doesn't make sense when he is doing the exact opposite with a die. Both are made to return the thread to class specs when applied properly, not to enlarge. I work in a machine shop as my day job for over 10 years and I have made more threads in more materials then most people have ever seen in a lifetime.

 

[Cobra Jet Steering LLC]

I agree 100 percent and I wanted to point out the danger of messing up that particular attachment point it's a critical point in the operation of the nozzle with a huge amount of force being directed inside it, plus Yamaha does not use any bushings just a single stand off that the cast nozzle pivots on so if the bolt is compromised in any way it will usually fail, even if people ignore something like thread locking compound or allowing it the proper curing time etc. So compromising the threads is a bad thing.

 

[Sbrown]

I was kind of pointing out that his comment about a tap doesn't make sense when he is doing the exact opposite with a die. Both are made to return the thread to class specs when applied properly, not to enlarge. I work in a machine shop as my day job for over 10 years and I have made more threads in more materials then most people have ever seen in a lifetime.

I have to agree. I was a machinist and I have never had a tap or die change my thread size other than intentionally.
I've also built many, many mechanical items, including high performance engines, transmissions, etc. I can tell you for sure, if there is an item that requires more than 1 bolt to secure it, you better start all the bolts before tightening any of them down. It's the best way to ensure everything is in alignment and nothing get cross threaded.

 

[seanmclean]

I don't own these, but I'm a bit confused about what the complaint is? Is he running a tap through the nylock nut - every time I've used those they are tight (supposed to be that way, as far as I know). The other points about making sure everything is threaded loosely before tightening is SOP for me whenever there are multiple attachment points.


Happy to be a test mule for JBP's next batch

 

[swatski]

I can tell you for sure, if there is an item that requires more than 1 bolt to secure it, you better start all the bolts before tightening any of them down. It's the best way to ensure everything is in alignment and nothing get cross threaded.

@Sbrown Incidentally, that would also be a very important tip for anyone with a 2015+ AR240 tower!
Even with that tip in mind the normal "procedure" Yamaha recommends in the manual is not sufficient to prevent tower collapse, IMO (due to bolts stripping and pulling out).

EDIT:
In order to really clamp down on those bolts and prevent them from pulling out, I posted a procedure that's worked for me, so far. A "fix" that uses a tap and no new parts, just some small hardware modifications and a special procedure for tightening the tower/hull brackets and hinge bolts. It's worked extremely well, IMO, the only drawback being - it'd be a pain if one needed to put the tower up and down a lot, such as for storage.
I would be interested in your feedback on this.
https://jetboaters.net/threads/2015-ar240-tower-fix.16089/#post-276367

--

 

[JetBoatPilot]

I think his concern was that the torque value we gave was exceeded when he was attempting to thread his bolt in place. I could be wrong on the torque value or the nylon on his bolts could be extra thick. I think running a tap through the threads is a good idea if you know what you're doing and don't cut new threads instead of simply cleaning out any crud that may be in there (remnants of locktite, corrosion, etc.)

 

[PeterB]

As one of the people who mentioned I chased the threads with a tap, my issue was not with torque or the nylon on the ew bolt. There was a portion of female thread that was exposed prior to installing the LT's. This was simply because the original bolt did not penetrate Saar as the new bolt. It was basically full of crud and some light corrosion. I ran a tap with very light force, and virtually no cuttings to clear the threads. This did not reshape the original threads. I then installed the bolt with loctite. I installed everything loose and then tightened everything.
Now just waiting to water test!

 

[Weeb]

I'm not a machinist but I use a thread chaser kit which doesn't cut new threads so it's a little less intrusive than a tap. I use to use a tap and then was informed I should use the chaser instead. I'm just a backyard mechanic so I could be wrong.

 

[Sbrown]

I'm not a machinist but I use a thread chaser kit which doesn't cut new threads so it's a little less intrusive than a tap. I use to use a tap and then was informed I should use the chaser instead. I'm just a backyard mechanic so I could be wrong.

Absolutely correct! This kind of situation is exactly what thread chasers were invented for. Chase already existing threads to straighten them up and clean them out without any chance of cutting new threads. An experienced hand can do it with a tap and die without damaging anything, though.

 

[Evil Sports]

I would be pissed if I had to modify the nozzle or parts I paid for. If its not plug and play Im probably going to have to pass. Waiting for more instal reviews.

 

[JetboatMN]

I have had the lateral thrusters installed for a couple of months now. First tried without them to see the difference. I have to say, I am very happy with the performance! I recently checked all the fittings and have not had any issues whatsoever.

Truly the best benefit of the thrusters is the confidence you have maneuvering in tight spaces. We frequently beach anchor, stern in, and routinely have to fit into a tight space between other anchored boats. I can park my 21 foot Limited on a dime no problem! Thanks @JetBoatPilot for a great product.

 

[TS4811]

Just spent my 2nd weekend on the water with the thrusters installed and what a difference. I had felt somewhat inept trying to maneuver our '17 SX210. I freely admit, despite years of piloting a variety of large cruisers (

twin screw) ​

and 30-50' sailboats, I was struggling with this one. We have a bit of current on the river, tragically short docks (14') and lots of traffic. Adding the thrusters has made all the difference in the world. the boat now responds to commands from the helm quickly and confidently. We can effectively balance the boat against a swift cross current. Again, what a difference.

Installation was a breeze, the video made it easy and the printed directions were clear. I think I had them installed in well under a half an hour with little effort.

Anyway my only regret is I didn't get them sooner, looking forward to the next innovation. ​

 

[Scottie]

I'll chime in here. The lateral thrusters are great. The reverse control is terrific. I often back in now just because it's easier. As far as installation goes... I suppose there's a number of possible scenarios, but in my experience, they were as bolt-on as bolt-on gets. Oh, and one more thing... Everybody duck... I'm running cobra fins with my lateral thrusters, no modifications, no problems.

 

[Markk]

I'll chime in here. The lateral thrusters are great. The reverse control is terrific. I often back in now just because it's easier. As far as installation goes... I suppose there's a number of possible scenarios, but in my experience, they were as bolt-on as bolt-on gets. Oh, and one more thing... Everybody duck... I'm running cobra fins with my lateral thrusters, no modifications, no problems.

Can you share a photo of your setup?