My 1996 Seadoo Challenger Overhaul

[A.J.C.]

Hey guys, I purchased a 1997 Sea Doo Challenger with the single 787cc engine. It came with a new engine (not installed) and 2004 trailer.

The old engine had already been removed by the previous owner since it was seized. I was left with a very dirty engine compartment and parts/bolts everywhere. I'm going to post my progress and ask a lot of questions so I appreciate the help in advance!

Here is what I'm working with:

Today I cleaned the engine compartment. Man, it was caked in oil. I scrubbed and rinsed it all day.

From this:

To this:

Here is my first of many questions. The original carburetors are pretty trashed. They are full of sludge and most of the phillips head bolts are stripped from a previous rebuild (not me). I bought some carbs off a 96' GSX. They look very similar minus a few components. I guess some of the parts can be swapped from my original carbs but I'm just speculating. Let me know if you think I can use these carbs as is or need to modify them. Here are some pics of the two sets of carbs.

Original Carbs

New Carbs

 

[BMANN06]

:thumbsup: I like!! Looking good in there!

 

[CLAYMORE]

Great start on the project...

 

[A.J.C.]

I started to drain the gas tank today. It has been in the tank for over a year but had stabilizer in it. It is also premixed. I think the best thing to do is drain as much as I can and start with fresh gas and the break in oil. I don't want to risk ruining my new engine.

When I was cleaning the engine bay, I discovered that the drive shaft for the pump had a lot of up and down play. Is this normal? I'm going to pull the pump and replace the bearing anyway but wasn't sure if it should have as much play as it does. I'm also a little concerned with aligning the engine. Do you guys think it will be cheaper to take the boat to someone when everything is complete and have them align it or just buy the tool?

 

[Dr Honda]

The newer GSX carbs are better. The original carb had an accell pump on it. They run just fine without one. Just clean, and verify the GSX carbs, and use the GSX Jetting. (or 96 XP jetting, and pop-off)

What did you use to clean the bilge?

If you are going to trash the original carbs... let me know. I can always use some parts carbs at the shop.

 

[SKETSEA]

l thought my engine bay was bad! Go
od luck with rebuild l had a blast with my 96 last summer.

 

[A.J.C.]

Thanks for the words of encouragement. I cleaned the bilge with Simple Green.

Dr. Honda, I'm going to hold on to my old carbs for now until I have everything running correctly. I will let you know.

I also pulled the jet pump today. I think I have an aftermarket impeller. Its stainless steel, not bronze. The wear ring looks pretty good. While I have the pump off, should I look for anything else? I really won't know if I have any problems with leaks until I get the engine running. Here are some pics. Let me know if you see anything out of the ordinary.

 

[Dr Honda]

The original impeller was SS... but that's not that factory prop.

Since you have the pump off... make sure you replace the neoprene seal. (it's the ring between the pump and the shoe) DO NOT use RTV to glue the pump back on with. If you do... it will be impossible to remove it if you need to. Also... clean, and put a nice big blob of waterproof grease on the driveshaft splines.

Yes... the wear ring looks fine.

 

[CLAYMORE]

One thing I noticed not mentioned yet was the washers or spacers on the hull. They sit between the hull and the jet pump housing. Mine had a large and extra large on the top studs and they stayed where they were found.

Your results, sizes and placement may differ as they are shims and not every alignment combo are exactly the same.

 

[A.J.C.]

The original impeller was SS... but that's not that factory prop.

Since you have the pump off... make sure you replace the neoprene seal. (it's the ring between the pump and the shoe) DO NOT use RTV to glue the pump back on with. If you do... it will be impossible to remove it if you need to. Also... clean, and put a nice big blob of waterproof grease on the driveshaft splines.


Yes... the wear ring looks fine.

Thanks for the help! I was lucky to get the pump off since it looks like someone used rtv. I'm making slow but steady progress. Tomorrow I'm going to finish transferring all the parts off the old motor onto the new motor, and put the pump back together. My plan is to have the boat in turn key shape by the end of this month. I go back to college in January. I have always wanted a boat and this was a very cheap one. I'm looking forward to using it in the spring.

 

[A.J.C.]

One thing I noticed not mentioned yet was the washers or spacers on the hull. They sit between the hull and the jet pump housing. Mine had a large and extra large on the top studs and they stayed where they were found.

Your results, sizes and placement may differ as they are shims and not every alignment combo are exactly the same.

I didnt notice any washers/ spacers between the pump and hull. I will look tomorrow. There are so many things I'm learning as a I go. I just bought a FSM so that should help a lot.

 

[Dr Honda]

The shims are a moot point. you have a new engine... so you need to do a proper alignment check on the drive.

 

[A.J.C.]

The shims are a moot point. you have a new engine... so you need to do a proper alignment check on the drive.

I can't wait for this part haha. This boat is going to nickel and dime me to death.

I made a little bit of progress today although it has been raining on and off. I sanded down the exhaust manifold, flywheel housing and cover. I tried to match the paint color to the engine but it turned out a little lighter. I think I'm just going to repaint them gloss black or try to match the exhaust which is purple. I don't know why SBT paints their engines silver when all the parts from the old engine that need to be transferred are off white. Oh well.

 

[blacter]

Just curious. What's the deal with the brand new engine? Are they still available? Did the seller run out of energy/enthusiasm?

 

[A.J.C.]

Blacter, It's a rebuilt engine from SBT. The seller had a project house boat and ran a business so he stated that he didn't have the time. It is weird that he disassembled the old engine and bought a new one and then decided to sell it. I guess he just got overwhelmed. At least I hope thats the case. I don't like surprises!

I have a few small updates. I started to swap over some of the parts on the new engine. I installed the motor mount support, flywheel housing and flywheel.

Quick question, would you sand the rust on this pto flywheel and run it or purchase a new one? I started to sand and its pitted.

Also, Is this the correct bolt for the exhaust manifold? It threads. Like I said earlier, I have bolts scattered everywhere from the previous owner.

Starting to look like an engine!

 

[Dr Honda]

Bolts are fine. If they go into the hole... they work.

As far as the PTO... I'd sand it, and polish it, and then measure it. If there are pits, or it's out of round... replace it. An air leak into the crank is bad.

 

[A.J.C.]

Bolts are fine. If they go into the hole... they work.

As far as the PTO... I'd sand it, and polish it, and then measure it. If there are pits, or it's out of round... replace it. An air leak into the crank is bad.

Thanks again Dr. Honda! Your help is greatly appreciated.

 

[A.J.C.]

I'm getting conflicting information about timing the rotary valve. My FSM says to align the 360 degree at the top of the mag inlet port. SBT's instructions says to align the 360 mark at bottom of mag inlet port. Which is correct? It will make a big difference in the timing.

My factory service manual

SBT's instructions

 

[Guest_User]

Post #21
http://www.seadooforum.com/showthre...1800-Restoration-Project-quot-Reel-Swell-quot

you need to make 2 marks...

For opening mark, first align 360° line of degree
wheel with BOTTOM of MAG side inlet
port. Then, find 147° line on degree wheel and
mark crankcase at this point


For closing mark, first align 360° line of degree
wheel with TOP of MAG side inlet port. Then,
find 65° line on degree wheel and mark crankcase
at this point.

 

[griz400]

look at this video, takes all guess work out http://www.youtube.com/watch?v=ULL5gfQs_UA

put 360 on bottom of mag side inlet, and mag piston at tdc then mark 147 and your good to go !!!

 

[A.J.C.]

Thanks for help guys! I didn't get any work done today on the boat. Tomorrow I'm going to time the rotary valve. I really need to take advantage of the warm weather we have been having and finish cleaning the bilge. I really didn't anticipate how much work this boat was going to take but I will happy when I have her running for the Spring.

 

[A.J.C.]

Ok, I finally got the pto flywheel tightened. I placed the engine in the bilge. It was getting dark so tomorrow I will start the process of hooking everything up.

What is the best way to get the engine to fit on the drive shaft?

 

[A.J.C.]

I made a little more progress today. I figured out I had to remove the front motor mount in order to slide the engine onto the drive shaft. I installed a few hoses and part of the exhaust. I hope to start the motor by the end of next week.

 

[enut]

I had the same boat but it was a 1997 before I traded in for the 1800 version. You must remove the pump and pull the drive shaft completely off of the boat. Mount the motor to the motor mounts first, then use an alignment tool to make sure the PTO is lined up to the thru hull fitting. Once this is done then you can re-install the shaft and pump assembly. It is important that you do this or you can damage the thru hull fitting, have unnecessary vibration and not have a good sealing carbon seal. There are people that rent out the tool or you can purchase one. You may want to make sure that you have the cylinder drain tubes all connected before the tuned pipe gets installed. It is hard to get to once the engine is mounted and the tuned pipe is installed.
Good luck with the install.

 

[Guest_User]

I made a little more progress today. I figured out I had to remove the front motor mount in order to slide the engine onto the drive shaft. I installed a few hoses and part of the exhaust. I hope to start the motor by the end of next week.

did you align the engine?