Just bought a project boat! 2006 Sportster 4tec 155

[Flightjunkie]

Hi guys.

I just bought a 2006 Sportster jet boat. The engine cranks over but had no compression on the center cylinder. I live in Hawaii, so corrosion issues were expected with this being a saltwater boat.

I couldn't get the rusted top hat floating ring off the driveshaft. Had to cut it. The Pump unit was stuck to the boat. I still can't get the reverse bracket off the pump. I broke one of the ears off while fighting with getting the pump loose from the boat.

Looks like I'm gonna have to cut the reverse bracket off the pump. I hope I can get the bolts out of the pump housing and don't have to buy that part too.

Does any one know where I can find a used "reverse gate support" that fits this boat for less then the $220 new price?

Thank you.

REVERSE GATE SUPPORT
204170214

 

[JPass]

Ouch. Hope you stole that boat, cause you're about to spend some $$ getting her back up and running.

You're gonna need a new carbon seal, impeller, possible pump housing, reverse bucket bracket, and possibly a new drive shaft.

That's before you even tear into the motor to fix the low compression issue.

 

[Flightjunkie]

Ouch. Hope you stole that boat, cause you're about to spend some $$ getting her back up and running.

You're gonna need a new carbon seal, impeller, possible pump housing, reverse bucket bracket, and possibly a new drive shaft.

That's before you even tear into the motor to fix the low compression issue.

Hi Jpass,

Yea. I knew what I was getting into. LoL.

Several years back I bought a 1986 Kawasaki 650sx. Lived it's whole life in Hawaii. So, had to fight these stainless / Aluminum corrosion issues on that one too. Also had 550sx and 750sx stand-ups.

When you live in Hawaii you learn to just deal with it.

I got the engine out. Pulled the intake and exhaust manifolds. Found the problem! It'll be a miracle if the piston is ok. Gotta pull the head next.

I got a bunch of new parts on the way! Yep, it's adding up fast!

 

[JPass]

Snapped valve stem. Nice to hear the piston is OK. I believe these are the sodium filled valves that the earlier boats came with. I've read they're troublesome.

Are you planning on replacing all of the valves with the later, non-sodium filled valves?

 

[Flightjunkie]

Snapped valve stem. Nice to hear the piston is OK. I believe these are the sodium filled valves that the earlier boats came with. I've read they're troublesome.

Are you planning on replacing all of the valves with the later, non-sodium filled valves?

Hi.

I haven't got the head off yet. So, I don't know about the piston. But, it cranks over fine and looks ok through the spark plug hole. It would be a miracle if the piston is ok. I've never seen a valve fall into a cylinder before and not had the piston cracked and the bore scored.

Stay tuned. I'll have the head off soon.

 

[Flightjunkie]

Hi guys.

Update!

I got the reverse support bracket off in pieces. I was able to get the bolts out of the pump housing so it looks like I'll be able to reuse that.

The corrosion on the motor was bad. The starter was corroded in. Broke the starter fighting to get it out. Got the PTO cover off after fighting each and and every bolt!

Got the head off. And sure enough, it's got the hollow stem valves. So, yea....no surprise one failed. The piston has a few dents in the top but no cracks. I'm gonna sleep on it and try to decide if I should change the piston and rebuild the bottom end, or just get new valves and stick to a head job.

The compression on #1 and #3 was 180psi. So, I might take my chances and run this dented piston.

The saga continues.....stay tuned for more updates.

 

[JPass]

Oof. Piston definitely made contact.

You weren't kidding about the rust.

That's a tough call on weather or not to replace the piston. Not sure I'd be OK leaving it, but I do understand the amount of additional work it would take to swap everything out.

Keep posting updates on your rebuild.

 

[MacSeaDoo]

I agree with JPass!

You need to replace the piston. You can't really tell what microscopic damage is done to the piston. The only way you will find out is to run the engine. Think of the work you are putting into this and think of doing it again.

I had a sled with a plug failure that had some marks on the piston. Used the scope and didn't look to bad. Cleaned it out, put a new plug back in. Ran great for 2 weeks, then the piston split in 2.

 

[MacSeaDoo]

BTW, on the positive side the cyl wall looks good.

 

[Flightjunkie]

I agree with JPass!

You need to replace the piston. You can't really tell what microscopic damage is done to the piston. The only way you will find out is to run the engine. Think of the work you are putting into this and think of doing it again.

I had a sled with a plug failure that had some marks on the piston. Used the scope and didn't look to bad. Cleaned it out, put a new plug back in. Ran great for 2 weeks, then the piston split in 2.

Not sure I'd be OK leaving it, but I do understand the amount of additional work it would take to swap everything out

Hi guys.

Yea, after sleeping on it I came to the same conclusion.... I will pull the piston inspect, and replace it. I'm trying to keep the cost down. When I get the piston out I'll look at the bearing inserts and rings and decide if I should replace anything else.

Just change the one piston? Re use the rings and bearings?

 

[JPass]

I wouldn't see the need to replace the other pistons considering you have great compression. I'd probably go with new rings, but I guess you could reuse the originals if they are in good shape and your end gaps are all within spec after installing them.

Bearings could also be reused considering you're not replacing the rod, so long as they check out OK.

 

[Flightjunkie]

Hi guys.

I'm still ordering parts and working on getting the bad piston out.

The guy at my local head shop said my head is an easy fix. He just needs to replace that valve seat. He told me to buy the valves and valve stem seals and he'll put it together for me.

I'm looking for valves. These OEM ones suck. They have the hollow stem. Do you know what OEM parts numbers are solid stem valves?

I got quoted $530 for a Riva performance valve set.

I see valves on eBay by "Caltric" for $113 for the whole set.

Looking for suggestions on what to buy.

 

[JPass]

Here are the parts numbers for a 2012 Speedster (no sportster this year) which will have the newer valves. This is for the 155 horse motor as I didn't see a supercharger on the motor pic you posted. I'm fairly certain these will work, but let's see if anyone else has any other suggestions.

 

[MacSeaDoo]

http://ipgparts.com/store/Supertech...-Set-for-Seadoo-4TEC-RXP-RXT-GTI-Engines.html

 

[Flightjunkie]

Here are the parts numbers for a 2012 Speedster (no sportster this year) which will have the newer valves. This is for the 155 horse motor as I didn't see a supercharger on the motor pic you posted. I'm fairly certain these will work, but let's see if anyone else has any other suggestions.

View attachment 52151

Those prices are for each valve! That over $700 for the set of OEM valves. Ouch.

 

[JPass]

Those prices are for each valve! That over $700 for the set of OEM valves. Ouch.

Pricey indeed.

I think the ones MacSeaDoo posted is by far the better deal. I don't have any experience with the brand, so I cannot vouch for them.

For the money, I'd probably roll dice and give them a try.

 

[Flightjunkie]

More rusted bolts to deal with.

Do you guys know where to get new bolts as a kit? I'd prefer stainless steel. These look like they're coated with something to help with corrosion, but it's not enough for life in the middle of the pacific ocean!

I can go to my local specialty bolt store. But, I'm sure I'm not the only one wanting to replace all these bolts. Motor mount bolts, case bolts, PTO cover bolts, oil cooler bolts, sensor mounting bolts, starter bolts. A bolt kit too much to ask for?

The bearings look good. The cylinder walls look good. The rod looks good. Even the piston looks like it would be fine, better safe than sorry.

I plan to just replace that one piston and it's rings. Re use everything else.

Thx for the advice on the valves. I'm still looks for cheaper valves, but I want something that will last.

Any recommendation for what type of sealant to use to glue this case back together?

Stay tuned for more updates!

Aloha!

 

[Flightjunkie]

Well......this project boat needed a few things.

$17 Drive shaft bellow
$110 ball bearing bellow
$95 used impeller
$23 two oil filters
$16 impeller nose cone
$14 impeller nose cone boot
$90 carbon ring kit
$105 floating ring removal tool
$21 compression gauge kit
$80 used starter bendix and solenoid
$29 stainless PTO cover bolts
$50 engine hatch cover gas struts
$190 reverse support gate bracket
$39 engine shaft alignment DIY tool
$23 PTO cover gasket
$75 valve stem seals
$36 rocker arm bolts
$105 head gasket
$342 Supertech valves
$80 head bolts
$51 crankshaft main bearing bolts
$19 rod bolts
$145 piston
$3 piston circlip
Total:
$1,758

Probably a couple hundred bucks at the head shop, a few more bolts, and odds and ends.... but, I think this is most of it.

 

[MacSeaDoo]

It is only money right?

Love watching others take on these types of projects as I know the effort that goes into rebuilding an engine.

Please keep posting lots of pictures for us who love to follow along.

There is a good set of regular posters here that have skill and experience that you can throw ideas or problems at.

 

[JPass]

Costs aren't too bad considering what you're having to replace. Nice to see the cross hatching on the cylinder walls are still present. Internals look good to go.

Definitely keep posting your progress so we can follow and help with any questions you may have.

 

[Flightjunkie]

Waiting on the parts to arrive so I yanked the trailer out from under the boat to give it some much needed TLC.

 

[MacSeaDoo]

Did the previous owner paint it with a spray can?

 

[Flightjunkie]

Hi.

I don't really know the history. But, I was told the boat was painted completely black for a movie. And then the guy who bought it after that painted it grey and yellow. He did a terrible job. The guy I bought it from bought it from that guy and then the engine failed on him and I got it cheap.

This boat has been poorly cared for. The trailer looks like none of the owners knew you were supposed to wash the saltwater off the axle and springs and rims. I chipped a couple of pounds of rust off the trailer. It's still structurally sound. Needs new 2x4s and a good paint job.

Once I get the boat running I plan do something about the cosmetics. Haven't decided what yet. The paint peels off pretty easy. Might strip it and paint it right with a good two stage paint or a marine / aviation paint like Dupont's Imron.

 

[Flightjunkie]

HI guys.

I'm still waiting on the parts. I got the trailer painted, and made new bunks. Chipped all the rust off, removed the rest with muriatic acid, neutralized with baking soda, washed that off really well, then etched with phosphoric acid, then wiped down with thinner and painted with an oil based enamel. Sprayed the rust prone parts with HD corrosion inhibitor. Made the new bunks out of treated 2x4s and used outdoor carpet.

Scrubbed the dirt and loose paint off the boat, and cleaned the engine compartment and inside of the hull.

I think I'm gonna work on the electrical next while I wait for the parts to arrive.

Stay tuned. Engine build coming up soon. More updates to follow.

 

[Flightjunkie]

Hi guys,

I got most of my parts in. Gonna take the head to the head shop to have the valve seat repaired, the valves and valve seals installed, and the head inspected for any other problems.

Hope to start rebuilding the motor next week.

Parts list so far!

$17 Drive shaft bellow
$110 ball bearing bellow
$95 used impeller
$23 two oil filters
$16 impeller nose cone
$14 impeller nose cone boot
$90 carbon ring kit
$105 floating ring removal tool
$21 compression gauge kit
$80 used starter bendix and solenoid
$29 stainless PTO cover bolts
$50 engine hatch cover gas struts
$190 reverse support gate bracket
$39 engine shaft alignment DIY tool
$23 PTO cover gasket
$75 valve stem seals
$36 rocker arm bolts
$105 head gasket
$342 Supertech valves
$80 head bolts
$51 crankshaft main bearing bolts
$19 rod bolts
$30 flywheel bolts
$145 piston
$3 piston circlip
$42 oil cooler used
$17 m8 x 1.25 x 110 reverse bracket bolts
$27 jet pump housing bushings
$60 stainless bolts kit for motor
$41 cover support post vivo marine
$15 exhaust hold down strap
$10 exhaust hold down clip
$52 forward compartment lift strut
$17 cockpit drain scupper
$12 stainless hinges beer cooler lid
$70 Johnson Pumps 08203-00 Ultima Combo Pump

Total:
$2,110