• Welcome to Jetboaters.net!

    We are delighted you have found your way to the best Jet Boaters Forum on the internet! Please consider Signing Up so that you can enjoy all the features and offers on the forum. We have members with boats from all the major manufacturers including Yamaha, Seadoo, Scarab and Chaparral. We don't email you SPAM, and the site is totally non-commercial. So what's to lose? IT IS FREE!

    Membership allows you to ask questions (no matter how mundane), meet up with other jet boaters, see full images (not just thumbnails), browse the member map and qualifies you for members only discounts offered by vendors who run specials for our members only! (It also gets rid of this banner!)

    free hit counter

Issues with Neutral

afdouble

Jet Boat Junkie
Messages
90
Reaction score
61
Points
137
Location
Upstate, South Carolina
Boat Make
Yamaha
Year
2017
Boat Model
242 Limited S E-Series
Boat Length
24
Mates--

I'm looking for some advice. At low speeds my boat (not engine) makes a slight knocking sound while in neutral or low speeds. It is almost like a rattle, but I don't feel anything or hear anything at the throttle. It appears to be coming from the back of the boat, likely the nozzles/buckets/etc...

Additionally, the boat has always remained steady (in one place) when it starts and is in neutral. Recently, the boat tends to move forward ever so slightly (enough to notice and have a rider ask why I had throttle in forward).

I am wondering if the sound and movement are related. Has anyone else experienced this? My first inclination was to check the reverse bucket. While I have never had any experience with this issue, I have read that the reverse bucket can causes rattling/knocking. When I looked, with the throttle engaged in the first forward position, the reverse bucket clears the water outlet. I don't think this is the issue.

What am I missing? Thanks in advance.
 
I would definitely take a good look at the buckets to begin with. Make sure they are closing all the way and that they haven't been knocked loose.
 
Sounds like your reverse gate needs adjusting. The knocking sound could be the gate hanging too low and bouncing off the jet stream. This could also explain your forward creep.

Here is an FAQ on adjusting it:

 
Thanks, i will check the buckets again. But I wonder, isn't the chattering felt because the bucket is too low (and hitting the jet stream)? Conversely, isn't the forward creep because the bucket is too high (and letting more jet stream out)? It seems as if I have conflicting problems.
 
Last edited:
My boat rattles a bit until it gets up to about 1400 rpm’s.
 
@afdouble and @Weeb - I realize that this is an old post, but I’ve been fighting the same issue for a while. I have a 2019 212X that I bought new in 2020. Im around 280hours at present. I’m wondering if either of your rattles got worse and you found the cause/solution to the issue?
 
Something else to check is excessive play in the love joy connection… the rubber cushion drives will wear out over time.
 
Just reach down in there and see if there is any play radially between the pump side of the love joy drive and the engine side… I know mine need replacing due to some play, and there is a bit of a rattle like noise I’m getting at idle. They’ll get changed out this winter.
 
I checked the lovejoy shaft and felt around as best I could. I didn’t feel any looseness or see any signs of rubber wear.

But…I did find that the bolts securing the IDS assembly to the bulkhead seemed to be loose. They easily rotated and I could move the washers around under a couple of the bolt heads. One of them tightened up from the bolt head side, but others need a partner to hold the nut on the back. Frankly, I’m surprised that even one would tighten without a wrench on the nut.
 
Well…Tightening the IDS assembly to bulkhead thru-bolts made a little improvement/change. This seems to have reduced the amplitude and the frequency a bit. I’m starting to lean towards the idea of a little slop between the impeller shaft and the lovejoy output shaft. I’m not sure that I want to chase this much further. I’ve read multiple complaints from others on the forum with the same issue from the same motor/drive. I’m kind of wondering if there’s a little more misalignment between engine and impeller shafts on the starboard side that’s driving a bit faster wear at the interface between lovejoy output and impeller shaft.
 
Well…Tightening the IDS assembly to bulkhead thru-bolts made a little improvement/change. This seems to have reduced the amplitude and the frequency a bit. I’m starting to lean towards the idea of a little slop between the impeller shaft and the lovejoy output shaft. I’m not sure that I want to chase this much further. I’ve read multiple complaints from others on the forum with the same issue from the same motor/drive. I’m kind of wondering if there’s a little more misalignment between engine and impeller shafts on the starboard side that’s driving a bit faster wear at the interface between lovejoy output and impeller shaft.
You’ve got this topic spread over several threads so it’s hard to keep track of.

How many hours are on this boat?
Have the intermediate bearings been greased ?
Have you pulled the pumps and checked the intermediate bearings for play without the pumps in?
From your responses it sounds like you need to make a better effort to check for play at the love joy connection to see if the rubber cush drive is worn out.
Have you pulled the cones on the back of the pumps and checked the grease and or water intrusion?

Do you have a shop manual? If not you need to get one.

Using a 1” wooden dowel or long screwdriver, and while the engine is running, place the dowel or screwdriver onto the intermediate bearing housing and then with your hand wrapped around the dowel, place the dowel up to your ear. This a mechanics stethoscope, and you can listen to the bearing, compare this to the other intermediate bearing as your problem seems to be asymmetrical.
 
Yes, I definitely have reached out on a few threads related to this issue. I’m sure that it’s difficult to follow where I’m at in the process. I should probably start a clean thread rather than hijacking other threads. But…

I have about 280 hours on both engines.
Both intermediate shafts have been greased.
I’ve pulled the pump with the noise and checked for play as well as run the engine without the impeller shaft installed - no play, no noise.
I’ve pulled the cone on the pump and inspected the cone bearing - all good, plenty of grease and no indication of water intrusion or bearing issues
I’ve inspected the impeller and housings for contact/wear - slight cavitation erosion on impeller with slight wear location on housing. I hand sanded housing and reinstalled with no change. This might be the issue, but the noise isn’t significant enough to warrant a new wear ring yet.
I’ve used a mechanic’s stethoscope to compare the sound at the bearing, but didn’t hear any appreciable difference.
I’m sure that a shop manual would be helpful.

Frankly, at this point I’m just going to keep monitoring the situation until it gets worse and is more easily diagnosed.

You mentioned that you have some rattle and need to change your lovejoy. I’m wondering how many hours are on your 2020 210FSH?
 
Yes, I definitely have reached out on a few threads related to this issue. I’m sure that it’s difficult to follow where I’m at in the process. I should probably start a clean thread rather than hijacking other threads. But…

I have about 280 hours on both engines.
Both intermediate shafts have been greased.
I’ve pulled the pump with the noise and checked for play as well as run the engine without the impeller shaft installed - no play, no noise.
I’ve pulled the cone on the pump and inspected the cone bearing - all good, plenty of grease and no indication of water intrusion or bearing issues
I’ve inspected the impeller and housings for contact/wear - slight cavitation erosion on impeller with slight wear location on housing. I hand sanded housing and reinstalled with no change. This might be the issue, but the noise isn’t significant enough to warrant a new wear ring yet.
I’ve used a mechanic’s stethoscope to compare the sound at the bearing, but didn’t hear any appreciable difference.
I’m sure that a shop manual would be helpful.

Frankly, at this point I’m just going to keep monitoring the situation until it gets worse and is more easily diagnosed.

You mentioned that you have some rattle and need to change your lovejoy. I’m wondering how many hours are on your 2020 210FSH?
735 hours on my 2020 210 FSH.

I got a set of these to put in this winter.

IMG_0278.jpeg

So, if you got no noise when the pump was out and you ran the engines, then the noise is associated with the intermediate shaft / impeller shaft interface and that slop is due to the power pulses that will make the impeller ring like a bell. Again, double check the play in the love joy coupler.
 
Last edited:
@afdouble and @Weeb - I realize that this is an old post, but I’ve been fighting the same issue for a while. I have a 2019 212X that I bought new in 2020. Im around 280hours at present. I’m wondering if either of your rattles got worse and you found the cause/solution to the issue?
I sold it at about 260 hrs. It never got better or worse. I just kicked up the no wake until it stopped.
 
Thanks for the response! This is the answer I was hoping for.
 
I checked the lovejoy shaft and felt around as best I could. I didn’t feel any looseness or see any signs of rubber wear.

But…I did find that the bolts securing the IDS assembly to the bulkhead seemed to be loose. They easily rotated and I could move the washers around under a couple of the bolt heads. One of them tightened up from the bolt head side, but others need a partner to hold the nut on the back. Frankly, I’m surprised that even one would tighten without a wrench on the nut.
What do you mean by “I checked the lovejoy shaft and felt around the best I could”? Did you remove the safety cover and roll the intermediate shaft coupler back and forth to check the play? This is hard to reach I know, build yourself a platform like I did as well as @madtom to give yourself something to lay on.

What you’re looking for is a rubber dampened feel or sensation as you roll the intermediate back and forth against the engine side of the coupler and not a click or metal to metal feel. I don’t think this is your issue since the sound went away when you removed the pump, but still worth checking. After some more checking around I’ve learned that these couplers need a bit of play in them, I’m going to check the play in the live joy couplers again but am leaning towards not replacing the cush drive as there is no metal to metal feel or click.

What was the gap between the impeller and the wear ring? You said there was a high spot you sanded, did you check the clearance? The gap range between the impeller and wear ring is .014”-.0177” but double check that in your shop manual.
 
Been traveling and away from the boat for a couple of weeks. I probably won’t get to check the gap until next week. Frankly, I don’t think I’m going to chase this much more until I get some more noise. I suspect that the noise is due to misalignment caused wear between the engine, intermediate shaft and the impeller shaft. I see that some have remedied the situation by adjusting shims under the engine or on the intermediate bearing housing.

I’ll check the gap between the impeller and wear ring sometime next week and get back to you.
 
Picked up my 2012 242 LS this year and have the exact same noise on the Starboard side. No noise with pump removed. Greased intermediate bearing, replaced jet cone grease, ensured everything was tight - noise is still there. As far as I can tell it completely goes away once I give it some RPM. Interested to see what you guys find out because it sounds like a bag of bolts but performs just fine.
 
Picked up my 2012 242 LS this year and have the exact same noise on the Starboard side. No noise with pump removed. Greased intermediate bearing, replaced jet cone grease, ensured everything was tight - noise is still there. As far as I can tell it completely goes away once I give it some RPM. Interested to see what you guys find out because it sounds like a bag of bolts but performs just fine.
It seems to me that the issue is likely caused by a little misalignment between the impeller shaft (male) and the lovejoy shaft (female). I’ve seen others report that they solved the issue by adjusting the alignment shims under the engine mounts. I suspect that playing with the shims between the intermediate bearing assembly and the rear bulkhead could also work. Every report that I’ve seen related to this noise has been on the starboard side only, which indicates to me that there’s a slight difference in key mounting points between the starboard and port side. I just don’t have the patience to play with shims to make the noise go away.
 
It seems to me that the issue is likely caused by a little misalignment between the impeller shaft (male) and the lovejoy shaft (female). I’ve seen others report that they solved the issue by adjusting the alignment shims under the engine mounts. Is suspect that playing with the shims between the intermediate bearing assembly and the rear bulkhead could also work. Every report that I’ve seen related to this noise has been on the starboard side only, which indicates to me that there’s a slight difference in key mounting points between the starboard and port side. I just don’t have the patience to play with shims to make the noise go away.
My wear ring and impeller look perfect. I've gotten to the point where I'm not going to think about it unless I have an issue.
 
Back
Top