Yamaha 242 limited

[Tom Denion]

Yes the speedometer is working, the test drive of the boat it got up to 50 MPH

I didn't get pictures because the mechanic just wanted to get it put back together he was sick of it tying up one of his stalls.

 

[Tom Denion]

JUST HAD A THOUGHT! Do your buckets move up and down over the jets nozzles like they are supposed to? I believe this could be your cause. If the buckets don't move up all the way and clear the jet nozzle opening, then the boat won't go like it should. Have you checked this prior?

Could be easily checked. Have someone in the Captains Chair move the throttles forward and reverse, while you stand at the back of your boat looking for the buckets to move up and down. Make sure you are getting full upward and downward movement. Engines off obviously.

I did not even think to look out the back of the boat to see if thrust was coming from both engines, and I need to check the bucket operation. I am leaving TX tomorrow and will be back in late may. Thank you very much for sharing your knowledge with me.

 

[Tom Denion]

Hi Todd, I just got back to Maryland, the more and more I think about I believe you are correct, both engines running at 4k the boat would not go over 15MPH. Before I bought it on a test drive it would go about 50mph. I did put some jet fins to help with steering at slow speed. I have never looked at the operation of the buckets. This has to be the problem with thrust, maybe I messed up something putting on the jet fins, but they were pretty straight forward.

 

[ToddW850]

Hi Todd, I just got back to Maryland, the more and more I think about I believe you are correct, both engines running at 4k the boat would not go over 15MPH. Before I bought it on a test drive it would go about 50mph. I did put some jet fins to help with steering at slow speed. I have never looked at the operation of the buckets. This has to be the problem with thrust, maybe I messed up something putting on the jet fins, but they were pretty straight forward.

Cool. Well, if that is it, then it would be a super quick fix and wouldn't cost you any money. Fingers crossed. Can't wait to hear the results.

ADDED: Yes, the install on both brands are pretty straight forward. Would be hard to miss putting one of the bolts back in place. Still doesn't hurt to check.

 

[Scottintexas]

I think back to the first page and you said the previous owner had to accelerate very slowly to get it up to 50mph.

I don't think your fin installment caused this.

Having to nurse it up to speed is classic symptom of cavitation or air intrusion. I would definitely look at your buckets, measure your impeller gap and inspect your impellers though because it's a very simple items to eliminate.

 

[Tom Denion]

Cool. Well, if that is it, then it would be a super quick fix and wouldn't cost you any money. Fingers crossed. Can't wait to hear the results.

ADDED: Yes, the install on both brands are pretty straight forward. Would be hard to miss putting one of the bolts back in place. Still doesn't hurt to check.

Hi Todd, I have been thinking about everything and I would like to throw this out there. Prior to buying the boat I had a test drive the boat reached 50 mph with no cavitation. The boat was towed to Texas where I installed cobra jet fins to both nozzles. While I was installing the fins and I needed to move the buckets I would move their positions by just grabbing the bucket in the back and moving it manually, is it possible by my manually moving the buckets from the rear that my port cable became disconnected from the throttle/bucket and the port bucket is always in the center position? On the video I made the port engine was always cavitating the SB would only cavitate when I really increased the throttle a lot. Do you know how the bucket cable connects to the hand controlls? Could they become disconnected by moving the buckets manually like I did? As always thanks for everyone's help on this.

 

[swatski]

Hi Todd, I have been thinking about everything and I would like to throw this out there. Prior to buying the boat I had a test drive the boat reached 50 mph with no cavitation. The boat was towed to Texas where I installed cobra jet fins to both nozzles. While I was installing the fins and I needed to move the buckets I would move their positions by just grabbing the bucket in the back and moving it manually, is it possible by my manually moving the buckets from the rear that my port cable became disconnected from the throttle/bucket and the port bucket is always in the center position? On the video I made the port engine was always cavitating the SB would only cavitate when I really increased the throttle a lot. Do you know how the bucket cable connects to the hand controlls? Could they become disconnected by moving the buckets manually like I did? As always thanks for everyone's help on this.

You have to disconnect the throttle/bucket cable if you take the nozzle/bucket/pump off. I don't think you could "accidentally" disconnect it. But, stranger things have happened.
You may be up to something... Maybe.

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[tdonoughue]

@Tom Denion , it is not likely. If something like that were to happen, it would most likely be disconnected on the back of the boat (on the jet).

I think the next step here is a) for us to get some good pics of the jets, impellers and intakes and b) for you to rebuild the plugs (we know that is needed anyway). If the buckets are disconnected (or one of them), it will be readily apparent to those on here who have worked with them so much. Similarly with the switched impeller theory or the intake-introducing-air theory or the impeller gap theory. A few good pics should have that narrowed down pretty quickly, I think.

 

[Tom Denion]

I think back to the first page and you said the previous owner had to accelerate very slowly to get it up to 50mph.

I don't think your fin installment caused this.

Having to nurse it up to speed is classic symptom of cavitation or air intrusion. I would definitely look at your buckets, measure your impeller gap and inspect your impellers though because it's a very simple items to eliminate.

OK thanks

 

[ToddW850]

Hi Todd, I have been thinking about everything and I would like to throw this out there. Prior to buying the boat I had a test drive the boat reached 50 mph with no cavitation. The boat was towed to Texas where I installed cobra jet fins to both nozzles. While I was installing the fins and I needed to move the buckets I would move their positions by just grabbing the bucket in the back and moving it manually, is it possible by my manually moving the buckets from the rear that my port cable became disconnected from the throttle/bucket and the port bucket is always in the center position? On the video I made the port engine was always cavitating the SB would only cavitate when I really increased the throttle a lot. Do you know how the bucket cable connects to the hand controlls? Could they become disconnected by moving the buckets manually like I did? As always thanks for everyone's help on this.

Sorry for the delay in responding back to you Tom. Good responses you got already.

But now I wonder something. You said while installing your fins, you had to move the buckets manually at the back of the boat. Just want to clarify. Are you talking you manually moved the buckets up and down? Or were you referring to moving the nozzles side to side. Just another thing to think of. I just went outside and moved my buckets up and down, manually from the back of the boat. It wasn't the easiest (plus I smashed my finger grrr). I'm just wondering if it bent the cable at some point in there. Not saying that's what it is, just a thought. But that will be easy to rule out or in, as soon as you are able to check the movement of your buckets up and down.

And like said above, as soon as you get back and can get us some pics, it will probably be obvious to us if anything looks out of place.

 

[Tom Denion]

Sorry for the delay in responding back to you Tom. Good responses you got already.

But now I wonder something. You said while installing your fins, you had to move the buckets manually at the back of the boat. Just want to clarify. Are you talking you manually moved the buckets up and down? Or were you referring to moving the nozzles side to side. Just another thing to think of. I just went outside and moved my buckets up and down, manually from the back of the boat. It wasn't the easiest (plus I smashed my finger grrr). I'm just wondering if it bent the cable at some point in there. Not saying that's what it is, just a thought. But that will be easy to rule out or in, as soon as you are able to check the movement of your buckets up and down.

And like said above, as soon as you get back and can get us some pics, it will probably be obvious to us if anything looks out of place.

I moved them up and down, they were hard to move manually that is why I was curious as to whether damage could be done by not using the controls to move the buckets. I was operating things in reverse. Thanks for your response and sorry you smashed your finger.

 

[ToddW850]

I moved them up and down, they were hard to move manually that is why I was curious as to whether damage could be done by not using the controls to move the buckets. I was operating things in reverse. Thanks for your response and sorry you smashed your finger.

Haha, no worries on my smashed finger. Just hoping we get this figured out for you.

 

[Tom Denion]

Hello all, I am currently in Maryland I will be returning to TX in late June and I have a question, I am convinced my port bucket is not moving and it is currently sitting in the neutral position. Without removing the boat from the water is possible to look at the throttle/bucket control right at the control position, has anyone taken apart the throttle control? I would like to see if a cable is disconnected before I pull the boat from the water. Sorry for the long absence currently receiving chemothearpy for treatment of Multiple Sclerosis. Still walking, but just barely, I get on and off my boat at the marina via a padded board I craw on and off it is working quite well for me. As all ways thanks for the help. Tom Denion

 

[Scottintexas]

We hope your recuperation continues well,

You (or someone else) should be able to look over the back of the boat and see if the buckets are moving,

to check the linkage, this is from our FAQ tab at the top of the page,
https://jetboaters.net/faq/how-to-stop-your-throttles-from-slipping-back-adjustments.44/

 

[tdonoughue]

Or, get a full-length mirror (like at the taylor) and stand it behind the boat. Then maybe you can see without crawling and hanging...

 

[mraz72]

observations from an ignorant observer...

so in the OPs video, there was a quick throttle (up to rev limiter) with NO resistance and that happened to the port engine ONLY if I remember correctly. So, it seems to me that whatever blows the water hard out of the back is not working on that side especially, and you guys are on that asking about the setup. Is the jet pump the only resistance on the motor? Is the impeller hooked directly to the crank shaft? What secures the impeller to the crank shaft?

also there was a post about not getting onto place with a single engine, I have never driven these on a single engine, I am not sure if leaving one engine at idle and blasting the other causes issues.

 

[Tom Denion]

I pulled both intake grates and there was very little sealant especially on the port engine. I also noticed the port grate where it meets the wear ring had a lot of pitting, I suspect I need a new one, however, for now I am going to put it into the water on Saturday morning, I can no longer leave it sit in my driveway due to homeowners rules. As you may recall the shop I had look at my boat that could not find anything wrong put in a bolt I could not get out (pic attached) it had no head the washer curled outward. I am hoping this reseal of the grates helps. If anyone has seen a bolt like the one pictured and has a way to get it out please let me know how. As usual thanks for your help. Just a FYI, I live near San Antonio and there are 3 Yamaha service shops around here, I called all 3 and I never got to talk to anyone in service, 2 went to voicemail and one had a recording that there was no one to take the call, of the 2 messages I left no one returned my call, if the water test fails I will look for a Yamaha dealer elsewhere maybe Houston.

 

[Tom Denion]

I resealed the grates it helped the port jet pump and made the starboard jet pump worse. I am going to pull the boat and replace everything impellers, wear rings, and grates, don't know what else to do at this point.

 

[swatski]

@Tom Denion Darned, I wish I was a little closer to your location, this drives me nuts. I'm sorry you are having all these problems!
I don't know if replacing the grates and even the wear rings is order. Impellers - probably. But we don't really know without some close up pics of those parts with different angles, and looking at the tolerances between the impellers and the wear rings. And it could still be something with the cleanout plugs, or transom plates with gaps at the transom...

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[Tom Denion]

Thanks swatski, I am at my wits end, I love the boat can't get it out of the marina, tried calling 3 Yamaha service centers in San Antonio TX and I never got to speak to a human, I am going to make a personal visit to one of them tomorrow to see what their backlog is at this time, if it is reasonable I am just going to tow it there, if the wait is too long I will tow the boat to my father-in-law's ranch which would give me the time to change everything. One thing I now worry about is I am not sure if the boat has enough thrust to get it on the trailer, I don't have a 4 wheel drive and my F150 has to go so far down the ramp it hits the slime and may get stuck, will work on finding a 4 wheel drive to remove this want-to-be boat from the water.