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2001 RX Reboot Project – MPEM related question

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"The engines undergo a four-point test program. Case and waterside pressure retention is tested by installing block-off plates on the engines and measuring leak down rates. Compression and squish is verified to be within the OEM guidelines by turning the engine over at starter speed."

I'm sure they do test them. But they didn't test with your reed cages installed. Any air leak past the carbs will cause a lean condition.
 
Hopefully you are using OEM mikuni kits and replace all soft parts with a new needle & seat. Not trying to be an ass, I've built a lot of these and the reed cages do leak sometimes. You won't know unless you pressure test.
What about the gaskets which were missing upon tear down of the 2nd carb? Do all carbs have the same gaskets under the main cover, or only the one that feeds the second?
 
So then why did you mention "Any air leak past the carbs will cause a lean condition" if that's not what I'm testing for in doing a leak test? The leak test in the manual seems to be exactly what they did at SBT. If I'm not able to test air past the carbs, what's the point?

It seems that painting the engine the wrong color or looking at it wrong may cause the engine to blow up.

I prefer to think that SBT is in the business of selling engines. If they have done everything they should do, and I do my part to make sure the parts I'm bolting back on are not damaged, have the appropriate sealant applied, and are torqued correctly, how could there possibly be a leak within the air passages they put together?

Additionally, if the pop-off pressure is within spec, the needles and seats are fine, and quite frankly, there is a screw in there that someone else may have partially stripped and I don't feel like messing with it since the pop off tested good.
 
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I figured there was something inside this little extra piece on the side of the float bowl that is not mentioned, talked about or shown in any manual. Why would anyone mention it or provide parts in the rebuild kit right? I mean that would make too much damn sense:

1681254352317.png

So I opened it to find another gasket with a pusher, a spring, etc.

1681254565925.png

What is the function of this, and where do I get the gasket because it's not a part of the official mikuni rebuild kit I purchased!

And, by the way, Mikuni's home company is in Japan, so saying foreign parts are shit (even China) is kind a moot point. Almost everything we buy nowadays is built, manufactured, whole in part in Japan, China or Thailand and most of our food is grown in Mexico where they allow topical pesticides we banned back in the 50's.
 
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So then why did you mention "Any air leak past the carbs will cause a lean condition" if that's not what I'm testing for in doing a leak test? The leak test in the manual seems to be exactly what they did at SBT. If I'm not able to test air past the carbs, what's the point?

What component(s) could cause an air leak past the carburators that would not have been pressure tested by SBT? Look over the service manual again. You installed them yourself.
 
I figured there was something inside this little extra piece on the side of the float bowl that is not mentioned, talked about or shown in any manual. Why would anyone mention it or provide parts in the rebuild kit right? I mean that would make too much damn sense:

View attachment 61765

So I opened it to find another gasket with a pusher, a spring, etc.

View attachment 61766

What is the function of this, and where do I get the gasket because it's not a part of the official mikuni rebuild kit I purchased!

And, by the way, Mikuni's home company is in Japan, so saying foreign parts are shit (even China) is kind a moot point. Almost everything we buy nowadays is built, manufactured, whole in part in Japan, China or Thailand and most of our food is grown in Mexico where they allow topical pesticides we banned back in the 50's.
This is in the service manual. Did you even read the fuel section? 😂
 
This is in the service manual. Did you even read the fuel section? 😂


If you aren't willing to help, and contribute to others knowledge, why comment at all?

People come to these forums for help from the community. We may not know everything, but we are willing to try and learn. I am a professor at two colleges. I teach graduate students, I write manuals, and I work in IT. Transfer of knowledge to someone who is willing to learn is how we all continue to grow. If I were to speak or communicate with one of my students even in a weekly discussion forum the way you have, I would not have a job. Perhaps you didn't mean to use the tone you did, and some people are lazy, but you spent the time reading the post, knew what it was an instead decided to ask if I bothered reading the manual.

Of course I looked through the manual - multiple times, and multiple "manuals." Even yesterday after working for 8 hours and going back at the project.

The problem? Seadoo's manual is not the most clear. The entire piece is #20 which has no name or reference on a parts list or in the instructions until a crappy photo from an angle that could or could not be the part:

1681307623969.png

And there are 2 #20's within the same diagram:

1681307694769.png

If this is what it is, the manual shows a picture of it from the worst angle because you can't even tell it's connected as a partial cover to a carb:

1681308053676.png

So again, a little helpful information as to what this is called, and where I can buy JUST THE DIAPHRAGM was what I was looking for and would have been appreciated since it did not come with the Mikuni carb rebuild kit, and I didn't want to guess.

But instead, I just spent another hour I could have been wrenching because for some reason no one with helpful knowledge they are willing to transfer to others responded.

And I believe I found it here:

1681309079395.png
So once again, thank you for your assistance.
 

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Moving forward....what I have found to be an unlisted part called a check valve within the fuel accelerator pump shown below broke when I tried to inspect it in order to be "thorough" while going through the carb rebuild process:

1681397690417.png

There is no part number listed on any website -- they show the area as empty except for the other diaphragm I already purchased. There is no rebuild kit that carries it. All I can find it's called an umbrella check valve. It's not specific to any make or model of carb; however, it is difficult to find it in the proper size for a small carb. Yesterday I spent about 3 hours driving around town to small carb shops, motorcycle shops, etc to no avail.

Amazon has the holley version for holley carbs (26-41) which claims to work and which will be arriving today and Jegs (specs don't match) . If that doesn't fit I will send it back, but any information on where to purchase this would be greatly appreciated. I am hesitant to try and cut down a larger one for the application. The only identifier on it is 149.
 
What component(s) could cause an air leak past the carburators that would not have been pressure tested by SBT? Look over the service manual again. You installed them yourself.
When I went to SBT yesterday, I asked about the leak test, and they indicated leak test provided in the manual has been done.

Engine leak test begins at section 04-02-1 (page 69) of the Seadoo service manual PDF which is used to diagnose engine problems such as poor performance, oil leakage, etc. prior to disassembly of the engine. However, the manual indicates static bench testing is the most effective way to conduct a leakage test which again is subject to disassembly of the engine.

Removal of external components listed below are not disassembly of the engine. It is also important to note that is is required to remove some of the components below to get the motor out of the ski. So it appears a static bench test (without a prior test environmet setup such as that @ SBT) would be possible. To do a static bench test, the motor would need to be out of the ski. This test claims to test engine cooling system, bottom end, and top end for leaks, prior to disassembly of the engine. The leak test kit even includes it's own hoses to test each component, so it's not like you're testing the hoses you're reinstalling which in and of themselves if not attached properly can cause leaks (note: page 70, "Use hoses provided in the kit and install them on the engine", etc.)

What gets installed back onto the engine core provided by SBT (and has been tested for leaks per the service manual specs prior to bolt on), all of which are arguably not parts of the engine itself:

Flywheel
Magneto
Bendix
Flywheel cover
PTO cover
PTO coupler
Starter
Reed valves
Reed valve covers
Exhaust manifold
Carbs
Oil pump
Tuned pipe
Hoses connected to all of the above
Electrical connectors to all of the above
Choke/fuel

Page 71 of the manual shows describes blocking the engine drain hose with a hose pincher, (1), and installing the pump to the water hose inlet, note, the engine is already of the ski:

1681404136656.png

There are many leak tests throughout the manual for each component, which I'm obviously doing as I work on the given items, i.e., pressure test the carb pop-offs, test the fuel accelerated vaccuum, etc.

However, I reiterate again, the Seadoo service manual indicates the purpose of the main engine leak test is to test the INTERNAL components of the engine and crank case, and the second to the RAVE valves (RFI) which comes pre-installed other than the caps by SBT which begins on page .

The main engine leak test installs block off plates to several areas including:

Carb install location
Rave valve install location
Exhaust manifold after re-installation
Intake plates (covering reed valves)

If I were to remove rave valves to install block off plates this will void warranty (if any bolt or fastener is removed from the block provided).

I'm not quite sure how an exhaust manifold would leak with proper inspection, and installation including new gaskets and sealant since it is all one big composite structure.

Page 73, indicates to check items which have already been verified by SBT save the small injection oil pump lines , the exhaust manifold and the intake manifold. With regard to the oil pump lines and fittings for air bubbles -- they haven't installed that yet, and can't even be primed until connected to the feed line within the ski itself, and I don't have my engine hovering on an engine lift.

Is there perhaps another leak test, i.e., you are referring to, and can you provide a page within the Seadoo Service manual you are referring to which would confirm I need to do yet another leak test after bolt on of the external parts?
 
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You have to pressure test with reed cages installed. They are most likely old and can leak air which will cause a run away and/or lean fuel mixture. I like to test with the exhaust manifold installed as well so know the water jacket is not leaking into the cylinders.
 
You have to pressure test with reed cages installed. They are most likely old and can leak air which will cause a run away and/or lean fuel mixture. I like to test with the exhaust manifold installed as well so know the water jacket is not leaking into the cylinders.
Here's the last one I did with some block off plates I made as an experiment.
 

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Here's the last one I did with some block off plates I made as an experiment.
They kind of appear like they were 3D printed.

I'm not even sure what you're testing in this pic, because, exhaust = out, and your pressure tester is hooked to the exhaust manifold which has a smaller connection to the ports the carbs attach to (right before the reeds)

Reed valves:

Reed valve allows the mixture to move in only one direction – from the carburetor to the crankcase. It prevents the mixture from moving back to the carburetor.

Why would you test pressure from exhaust to carbs?

You also have block off plates on the RAVE valves which are also related to the exhaust, not input from the reed valves or backward pressure to the carbs. Regardless, I can't remove my RAVE valves because any bolt included with the engine that has been removed voids warranty.

Are you sure you're testing reed valve leakage?

If were testing reed valve leakage, I would think I would want to test reverse pressure from the opposite side of the reed where it can reverse back into the carb.

Just a thought.

Because in your scenario, it would seem all you're really testing is that the reed valve is opening properly toward the crankcase.
 
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You have to pressure test with reed cages installed. They are most likely old and can leak air which will cause a run away and/or lean fuel mixture. I like to test with the exhaust manifold installed as well so know the water jacket is not leaking into the cylinders.
I shot a 70PSI water hose through the front of the reed valves (which face with the pointed end inward) and they did not open; however, manually I was able to push them open with a finger. So unless they are going to leak from somewhere else like around the seat area....seems like a lot of work for something that could be pressure tested with a water hose prior to install.
 
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Moving forward....what I have found to be an unlisted part called a check valve within the fuel accelerator pump shown below broke when I tried to inspect it in order to be "thorough" while going through the carb rebuild process:

View attachment 61788

There is no part number listed on any website -- they show the area as empty except for the other diaphragm I already purchased. There is no rebuild kit that carries it. All I can find it's called an umbrella check valve. It's not specific to any make or model of carb; however, it is difficult to find it in the proper size for a small carb. Yesterday I spent about 3 hours driving around town to small carb shops, motorcycle shops, etc to no avail.

Amazon has the holley version for holley carbs (26-41) which claims to work and which will be arriving today and Jegs (specs don't match) . If that doesn't fit I will send it back, but any information on where to purchase this would be greatly appreciated. I am hesitant to try and cut down a larger one for the application. The only identifier on it is 149.

The ones that arrived are still not the right size, so plan #2, trace and modify to fit.
 
You have to pressure test with reed cages installed. They are most likely old and can leak air which will cause a run away and/or lean fuel mixture. I like to test with the exhaust manifold installed as well so know the water jacket is not leaking into the cylinders.
In my case, the water jacket has already been tested before purchase.
 
I don't know why this fuel fitting was plastic, but the lines were hard, so in attempting to cut the oieteker clamps off, the t-part broke. I would like to replace it with a brass fitting moving forward. I can't even find the part number in a manual anywhere. Does anyone have a source?

1681594982603.png
 
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All you need is a Tee unless I'm looking at the wrong fitting. Hardware store should have that and likely one in plastic as well. this is my accelerator pump test rig. LOL I like verifying that it is all working before I install the carbs. :D

GTX Limited Carbs Complete (4).JPEG
 
All you need is a Tee unless I'm looking at the wrong fitting. Hardware store should have that and likely one in plastic as well. this is my accelerator pump test rig. LOL I like verifying that it is all working before I install the carbs. :D

View attachment 61801
Nope. Went to Ace hardware this morning. The t-fitting is in between 1/8 and 1/4, so it's a 3/16 apparently or some weird metric fuel line size. I'm going to have to look up the specs on Partzilla. Nope...Partizilla doesn't have specs either. Amazon it is. 3 for 6.99.

Oh well, at least the fuel line will be clear and match the ski colors:

1681656531049.png


And I ended up going with a brass fitting that should never break or go bad.
 
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I hope tht blue stuff isn't the crap I bought a while back. I couldn't even uncoil it. I stretched it out and used a heat gun on it to try to straighten it. What a mess. :D :D I didn't use it. Good Luck.
 
I hope so too. If so I'll send it back. Gotta love amazon. I have spent so much money driving around for such little return at times.

I figure I'll let it sit in the Florida sun for a few like I did the VTS boot :)

My friend said the same thing about the fuel line, but the reviews on Amazon said nothing of the sort.
 
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if so I'll send it back. gotta love amazon. I have spent so much money driving around for such little return at times.
Last post here, can't stand people who just buy to try and return. Completely kills a small reseller. If you can't even mic a fuel line to know what size it is, you should probably pay a shop. On top of that, all the advice given to you goes right over your head. Good luck with your ski.
 
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Last post here, can't stand people who just buy to try and return. Completely kills a small reseller. If you can't even mic a fuel line to know what size it is, you should probably pay a shop. On top of that, all the advice given to you goes right over your head. Good luck with your ski.
Again, your erroneous judgmental opinion.

Yes I could have measured the 21 year old line to test it with the micron measurement tool; however:

1) They are old and hoses shrink/expand, etc.
2) My micron measurement tool has a dead battery anyway
3) Didn't feel like buying another one, nor spending more gas to go buy one since my vehicle takes 93 octane
4) A good manual and parts lists includes the spec of every part, piece, and supply

I don't buy to just try and then return. Apparently you don't spend much time reading follow-up posts or the posts go right over your head before you jump on here and start with your condescending tone once again.

1. I can't buy something locally that doesn't fit and isn't available****.

2. I spent hours driving around and tanks of gas to find the right size parts and they don't exist locally.

3. I used these trips to find the right sizes, so I knew what to order.

4. When I buy online, I match up the specs and look at reviews.

5. If the specs aren't right, nor are listed right, it is not my problem. (For instance I purchase a key listed as DESS, I get it, and it's not for DESS).

6. The blue line has good reviews on Amazon, but etemplet, and even one of my friends said he bought the same line and it was hard to work with. There was no mention of that in the reviews.

I got it. You think I am not capable of fixing my own ski when I read / digest and apply 700 page manuals more complicated and properly written than the seadoo one. The manuals I read and apply are based upon far more complex subjects than simple combustion engines. For instance, 2000 node networks with firewalls, IDS, IPS, cloud storage, end to end encryption, dual factor security (if not triple factor), in mixed environments utilizing Linux, Mac, Windows, Android, iOS and whatever adaptations gets thrown my way for business needs. I do it well because I know exactly how each piece interoperates and functions. I also do Cybersecurity, Incident Response, and Penetration Testing in situations where there is no manual available to follow.

So when I have someone tell me ....just do this but you can't explain how you're testing what you claim to be, I'm skeptical.

And last but not least, who are you to tell me not to work on one of my own skis and use the forums as designed? You are not required to respond with no helpful information once again.

So far the only thing I have broken are two stripped screws (which were reused by the "mechanics" that did the work) and quite frankly I know I'm more detailed than any individual I have paid to work on my jetski in the past since I have now seen their shoddy work. How do you leave bolts out of the lower tuned pipe or charge me for work you never do?

It may take me a little bit longer to do the work because I have to fabricate a tool or source a part, or clean up a part manually because I opted not to buy a parts washer, but if something does go awry, at least I'm on the lookout for it.
 
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