96 HX Carb Rebuild (lots of pics for beginners to see!)

[JPX]

EDIT: After going through all this, I though it would be appropriate to list all the resources I used for successfully bringing revs back to my HX and completing a perfect carb rebuild (my first time no less!).
Excellent carb rebuild guide thread by qstorm.
seadoosnipe's carb theory guide thread
Seadoosource's most excellent carb rebuild kit - all in one
Seadoo's official parts guide link

And I have consolidated fuel delivery problems under this How To Thread -> http://seadooforum.com/showthread.php?t=5563

A continuation of my 96 HX headaches - last episode can be seen here with the exhaust pipe water leak->http://seadooforum.com/showthread.php?t=588

I decided to go whole hog tonight to take off the carbs. I've taken apart cars, engines, suspension, brakes and fuel injection. But I gotta say, I don't like carbs and this is my first experience with them hand-to-hand.

Okay, that said, here is what went down.

I took off the airbox and spark arrestor. Disconnected the throttle cables and the choke cable. Unbolted, well, everything.

And since I am replacing fuel hose anyway, I simply cut the hose so I can deal with the crimped clamps on the bench.

Intake plenum at the engine and carbs off:


Port side and MAG side:


Underside: This is the part that threw me off a little this evening. I was under the impression that there was an idle screw on both carbs. But it is only on the MAG carb.


I also peeled back the fuel line to see exactly what all the fuss is about with the gray fuel hose. Yeah, this stuff sucks.

 

[JPX]

I took apart my PTO carb's regulator plate:


Not sure if this is good or bad....but there is certainly junk that accumlates on the bottom edge of the diaphragm. And the wrinkling of the rubber at 12, 3, 6, and 9 o'clock positions suggests it is getting long on the tooth. Without a rebuild kit in my hands, I can't compare good to bad right now.


And boy do I have a lot of crimped hose clamps to undo. Yeesh.

 

[95SeadooHxr]

looks liek i might be needing to thoroughly rebuild my carbs as well do to major bog issues. I am glad you posted these pics!

 

[95SeadooHxr]

do you know if 96 hx carbs are the same as 95's? also what size are the carbs i need a rebuild kit for my 95 but cant figure out what size they are.

 

[timmyboy76]

95...what i posted for your ski on other thread, is stock carbs and oem #'s. If you want 96' carbs, #'s are..270500280/mag, 270500281/pto, but there jetted different than yours, with stock application..pipe,intake..etc
Main 130, 75pilot, LSA=1.5

 

[JPX]

I have a spool of fuel hose and a bunch of hose clamps to keep me busy while I wait for the carb gasket kit that should arrive next week.


I also grabbed some parts from a friend to cobble together a homebrew popoff valve tester. Uses a bike pump (or small air compressor), an air gauge, and various hose connectors.

 

[timmyboy76]

lol.....exactly what I used..bicycle pump(old-school, foot pump), worked KILLER...Harbor Freight $5.00 bones.

 

[JPX]

:ack:Today I've been working on the tedious task of removing the factory Oetiker hose clamps and running the new fuel hose.

My preferred method is to use a large diagonal cutter to squeeze the clamp TIGHTER to get enough slack to pry it open. It helps to have 8 hands to do this Once the clamp pops open, the end can be peeled back past the "tag" and opened fully. The carb clamps are hell. But the clamps on the rest of the boat are easier.


To make it easier to reach the clamps at the fuel tank, I pulled out the fuel filler neck and the breather tubes. I did a quick check with a vacuum pump (used in bleeding brakes) to make sure the 2 check valves actuate. HX has them under the filler bezel - most of you guys will find these check valves inside the hull above the fuel tank.


Now it is much easier to get into the fuel tank connections. Also could get a good look at the PTO....and it looks okay.


Next up was removing the fuel selector valve:


I blew it out with compressed air and it is clear. The grey hose and that green goop is something else. :ack: And label, label, label everything. It's not that hard to track pulling one hose at a time, cutting to length and reinstalling. But if you yank everything at the same time, it can get confusing.

 

[JPX]

In my haste to remove the carbs from the hull, I cut a hose that I shouldn't have - the pulse hose from the engine block to the MAG carb. So I cut a new fuel hose section to make up for that bonehead move.


Then I pulled out the fuel baffle (sender) from the tank. For those of you that don't know, the HX doesn't have a fuel gauge - and also there is no circuit board or float inside the baffle.


Changed out the fuel hoses on the baffle and the vent line (baffle to the check valve that goes out of the hull. All hoses are now replaced! :coolgleam:

While the HX is down, I've been letting the kids drive their Barbie Jeep using the boat's 12V battery. No sense in buying a Power Wheels battery for $70 when I already have a sealed battery!

 

[JPX]

Okay, back to the carbs themselves:
Took off the regulator block and was very surprised to see this rusty spot on the check valve screw. Here is a close up of the corrosion on the carb body .:ack:


Can't wait for the kit to come in the mail. With the hosing all done, I just want to get this thing back together.:toetap05:

 

[95SeadooHxr]

fantastic write up!

 

[derek]

lawnmower battery. $20 at autozone. run the barbie car just fine. i use them in seadoos.

 

[JPX]

This morning I was pacing around the garage trying to find something to do before the mailman showed up.

I tore apart my workbench rewiring all the electrical strips and just basically fussing. Once I finished that, I took apart the ignition box to see if anything interesting was going on. Fortunately, other than a minor seepage everything looked perfect - (incredible considering the submarining I put this thing through the 13 years I've owned it).



I sat down at the workbench and surfed the web. And then the mailman came by!:hurray: The only doubt I have at the moment is the spring selection for the needle valve. The dark one is the original and the one on the left is what appears to be the best fit. What exactly is the bright silver one for (it is a lot longer)?

 

[95SeadooHxr]

i think it has to do with teh pop off, it should say some where how many grams it is, i was told with a stock jet (1.2ns) it should be 44 grams? some one can correct me if i am wrong.

 

[JPX]

Well, I decided to run with 42psi popoff on both carbs using the original springs. The new ones (dark silver) were giving me 39-40psi. HX spec is 40-56psi.

And WOW those stainless steel nex cap screws for the diaphragm plates ROCK! Boo hiss for the original Philips head screws that strip out.:bs:


After replacing the last few inches of fuel hose, the carbs were ready to remount to the intake manifold.


Now I just need to remember how to route all the hoses and cables so I can fire this thing tonight.


With any luck, the HX will be in a tunable state tomorrow morning! *crossing fingers*.

I'll tell you what : thank GAWD for the internetz during this project. I couldn't imagine trying to take these things apart and fiddle around with them without the mountains of info availlable on this forum.

 

[JPX]

Got the carbs mounted after dinner. Drank a little bit too much red wine and had a TON of fun remembering which way the lever for the oil injection while mounting up the cable. But got it all bolted on and it looks like it might actually work.:bigear: This is what everything looks like with new replacement fuel hose and the remounted/rebuilt carbureators.


:hurray: AND IT WORKS! Well, at least it starts and idles. It had absolutely no problem firing right up......but that's how it was before the teardown. The real test is if it runs correctly IN THE WATER.:toetap05:

So I gathered up my stuff - and some tools - to take to the launch ramp for final tuning and testing. This is VERY exciting stuff! I actually am going to bed BEFORE midnight for change so I am well rested for tomorrow.

Stay tuned!:hat:

 

[JPX]

VICTORY!​

But it wasn't an easy one.

There were two launches today. The first launch resulted in an agreeable idle in the water. But with more throttle, it still would not rev up (it revved fine out of water). I started over with the low speed adjusters to make sure I didn't miscount the turns. Still not going all the way up to revs.....it was a bit better after the carb rebuild, but STILL not quite right.:toetap05:

This left me just a hair better than where I was BEFORE the carb rebuild. What was somewhat reassuring was that nothing was leaking and everything seemed to be assembled correctly. It's just that I was driving a 20mph HX.

So I pulled the boat out of the water and cleaned it up in preparation to go home. But I was thirsty - so I busted out a snack and a soda in the parking lot. I gave it some additional thought.....fuel, all of it, was good. Something else wasn't working......spark?

I checked for spark at the plugs. It was there, but it wasn't telling me a whole lot. Then I grounded the PTO plug and tried to start with the MAG plug wired. It wouldn't start.

I then grounded the MAG plug and wired the PTO plug - and the engine started (albeit badly as only one cylinder was connected)! :bigear:

Ah! Something that changes when I change it! So I switched the two spark plugs and wired them both - it ran even worse than before. At this point I knew I had at least one bad plug.

I dashed into town, HX in tow, to find an auto parts store. And they had my NGK BR8ES in stock for only $2 a plug (wow, how come my car plugs aren't that cheap?)

I drove back to the dock for launch #2, installed the new plugs, and the idle was again agreeable, but I had to get out of the 5mph zone to goose it.

And BOY did it ever goose! :hurray: It's like 1996 all over again - I have a 52mph boat that does shoulder-joint-popping hole shots. And I forgot what a pounding 52mph feels like when riding a windy day in the San Francisco Bay. :boxing_smiley:

I can't sell this thing yet.....I'm not quite done with it yet now that it runs like the ferocious beast I bought 13 years ago.

 

[Woodstockaz]

Awesome post

Really an awesome post!
Than you for the pics too!
Question. What is your out of water idle? Did you run into any idle issues in this rebuild?

 

[JPX]

I had idle set at around 1700 RPM out of the water BEFORE the spark plug change. I carried A LOT of tools with me to the water yesterday, but a timing light wasn't one of them.

Now it is idling a bit more than 3000rpm out of water.....and it wants to run away a little during flush. So I will probably lower the idle a bit more on the next outing.

 

[alane2526]

Thank You for the write up!!!

I'm new to the site and wanted to thank everyone for all the information here. I have particularly found this carb rebuild thread helpful , as I will in the VERY near future be undertaking this same task on the SAME model boat. This '96 HX needs at least one carb rebuilt and probably some electrical work as well. I'm not sure what kinda shape the boat is in other than it's got new rings and pistons in it (and that the carbs need to be rebuilt.) I plan on changing the fuel lines as well , I wasn't real thrilled with them on the '95 XP 800 I had either.

Oh well ... Lots of work in my future, but I cant wait to rejoin the ranks of the Seadoo owners/riders!!

Congratulations on your HX carb rebuild and I'm sure I'll be conversing with alot of you very soon!

Thanks in Advance!
-Alan

 

[2strokejunkies]

This is a great thread on rebuilding carbs....great job...

 

[mikemopar]

JPX...
This was not only a good post but a great post. It sure took the butterflys out of the old tummy when I was confronted with the classic bogging problem on my 96 GSX.
On out last river run I could not get above 30mph and when I switched the fuel to reserve it died. sounds like a case of severe fuel cardio arrest. So I Googled the problem and came accross your thread. You put the light at the end of the tunnel.
I'm halfway done changing out the fuel lines and blew out a chunk of rubber in the reserve side of the fuel valve which thats takes care of the reserve problem.

Q. What kit did you get for the carbs? My inspection showed the filters were not bad. Would you recommend a full kit verses just replacing the filters.

Also, on the GSX, any tricks on pulling the sending unit out of the tank? It appears there isn't enough room unless you remove or tilt the tank. And last is there any identification on which line goes where on the 4 ports on the sending unit. I marked them and will put back as marked but always like to confirm its right.

Thanks
Mike

 

[JPX]

Wow - chunk of something from fuel valve, eh?

Thanks for the kind words on the post. I needed a kick in the pants from fellow seadooforum.com guys myself to dive in and work on the carbs myself. So all I can give back is anything I can share that inspires others to take on the work themselves with some confidence.

I got the kit for the carbs from http://seadoosource.com/carbpkgs.html. In theory you could just clean the filters and go.....but I figured 12 years of ownership and carbs halfway torn down warranted a full rebuild anyway.

The baffle has marking on the ports for the correct hose. So you still have a reference point if a label pops off a hose. If you get lost on the fuel lines, this diagram will help a little.

This thread sheds some dim light on the fuel sender extraction.....it ain't pretty. http://www.seadooforum.com/showthread.php?t=7760