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SX230 Resurrection

Brad_Ct

Jetboaters Captain
Messages
649
Reaction score
685
Points
242
Location
Alva Fl
Boat Make
Yamaha
Year
2006
Boat Model
SX
Boat Length
23
As some of you know I bought a 2006 SX230 from veedubtek last month and as he described it is rough with both engines seized.

That being said the first thing I did was to pour Marvel Mystery oil into the cylinders and covered it up expecting to not do anything to it until after winter. Well today it was almost 70 and I got out of work early and my curiosity got the best of me so I pulled enough of the cover off to get the into the engine compartment to see what I could see.

I pulled the starboard coupler shield off and found that somehow the bilge pump hose had gotten wrapped up in the intermediate shaft and was still attached to the end of the hose going out of the boat. I am guessing this happened at a low speed and killed the engine. After removing the hose I put a pipe wrench on the coupler and tried to turn the engine over to no avail. I put some more oil in the cylinders and moved over to the port engine.

I removed the coupler shield and with a pipe wrench on the coupler to my surprise with a couple whacks on the end of the wrench with my hand I was able to get it to free it up. After rotating the engine back and fourth several times I was able to get full rotation. Not sure how much damage has been done but I think at this point this engine can be saved. Put more oil in the cylinders put the plugs in and covered it back up most likely until spring.

@veedubtek You went above and beyond with everything you did to get the boat and trailer ready for the shipper, thank you!!IMG_1296.JPG IMG_1303.JPG
 
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Congratulations on your purchase, It's going to be a journey!

never seen that happen to a bilge pump hose before,

what type of mechanical experience do you have? Have you ever tore an engine all the way down?

I would have thought it would be best just to pull the engines out and get them sorted on a stand,
 
Mystery oil is great stuff. I started using that when I was a teenager in the 70’s.
 
@Scottintexas I was an auto mechanic for 10 years and have been in the HVAC field for the past 30. Restored several cars including rebuilding the engines so I'm not to worried about these. My biggest concern is if I need machine work done, going to have to do some research to see if there is anyone good in my area.

Built this with my fathers help in 1974.
 

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Mystery oil is great stuff. I started using that when I was a teenager in the 70’s.
I've brought a number of first gen RX7's back to life with that stuff. Let it sit and soak on the apex and side seals for a few days. Charge a battery, then fire it up. Smokes like dammit, but often fixes a stuck seal. Had a guy bet me the cost of the car it was a blown motor. Ended up getting that car for $100 total, and smiled as I drove it away!
 
@Scottintexas I was an auto mechanic for 10 years and have been in the HVAC field for the past 30. Restored several cars including rebuilding the engines so I'm not to worried about these. My biggest concern is if I need machine work done, going to have to do some research to see if there is anyone good in my area.

Built this with my fathers help in 1974.
Good luck with this project! Watching.

Fortunately, there are guys here that can help! Like @Scottintexas - there is a number of real world experts in MR-1 everything here including @Jgorm @itsdgm @buckbuck @boudin @cybuch - to name just a few legendary members w/extensive MR-1 rebuilds.

So, there is ton of info and entire rebuild threads by some of those members. Really awesome stuff.

--
 
Good luck with this project! Watching.

Fortunately, there are guys here that can help! Like @Scottintexas - there is a number of real world experts in MR-1 everything here including @Jgorm @itsdgm @buckbuck @boudin @cybuch - to name just a few legendary members w/extensive MR-1 rebuilds.

So, there is ton of info and entire rebuild threads by some of those members. Really awesome stuff.

--
Thanks for passing that information on to me, I’m sure I will be reading and asking questions. I really would like to pull the engines before winter but I’m not sure if that is going to happen.
 
Is that the bilge pump hose or is that the hose to the infamous plastic scupper? Could be that it broke off wrapped around the shaft and killed the engine. That may have been it for the previous owner when it was in service and has sat since. Could be more of refurbish than replace lots of parts.
 
that was my first thought also but when he said it was the bilge hose I figured he knew better,

it would certainly make for a believable scenario, somehow the scupper hose comes loose ends up wrapped around the shaft, tears out of the scupper causing the boat to partially submerge, ????

Good luck Brad and I can't believe your going to make us wait over the winter,
 
I'd put new plugs in and try to fire it asap. Blow the crud out and distribute oil. I find a shop that worked on sport bike engines and they did a great job on my heads. Look at my thread in this section called jgorms build or something like that for lots of pictures.
 
It is definitely the bilge line, not really sure how that could happen but it did. I’m thinking that killed the engine and they ran on one engine and filled it with water and then it sat.

I do have a friend that has a heated garage with a electric chain hoist on a trolly so I do have a place to pull the engines but I have a lot of plans until after the first of the year and then it’s snowmobile season.
 
It is finally going to be warm enough here to get back to work on this thing, pulled the cover off yesterday and tried to free up the starboard engine after letting it sit with marvel mystery oil in the cylinders over the winter and it’s still stuck. Going to pump as much of the old gas out of the tank and try starting the port engine after I fix some electrical issues this weekend. Both of the pumps are off the boat because the wear rings and impellers bind, can I run the engine with the pump off without causing a problem?
 
Yeah, no reason you can't. Don't rev it too quickly. It might be worth using a metal rod and knocking each piston with a hammer to loosen it up, or it might put a hole in the piston. (I'd do it if it were my boat) if also try a large strap wrench in the coupler.
 
I tried the rod idea on my Exciter when I bought bought that with a seized engine but ended up having to pull the head. I think the problem I’m having is two fold as far as getting it freed up. The first is that I can’t get a grip on the engine side coupler and have the rubber part of the coupler acting as a cushion and there is the reduction gear assembly also. I actually loosened the engine side coupler on the output shaft by trying to free it up, last registration sticker is 2016 so I think it has been set up for years.
 
What's the back story on the boat? Any idea why the engines are seized up?
 
It might be worth hooking up a compression tester hose and hitting each cylinder with 120psi. Dump in a spoon full of oil first. It won't work on the cylinders with valves open, but one of them should be on the compression or power stoke. 120psi on a roughly 3" piston will generate 800lbs of force.
 
That might work but at this point I know the engine is going to have to come apart. One of the electrical issues was that the battery cable from the battery and starter relay was broken off and the ECM box was hanging from one bolt so I removed the box completely and opened it up. Relay is shot and someone had done a real hack job fixing the ground wire previously. The ECM does not look like it got wet so hopefully I don't have to deal with that expense.

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Spent the day working on it, pumped approximately 20 gallons of old gas out of the tank and putting about that much fresh gas back in it along with two cans of seafoam. Put a good battery in it and tried to start the port engine and got nothing, traced out the problem to a bad ground for the starter solenoid. Got engine to turn over but it would not start, all the coils ohmed out good but with a plug grounded I had no spark. Thinking the ECM is the problem but I'm not sure if anything else could be causing the issue, any input on this?

Started looking at other things and found that the navigation lights, blowers, bilge pump, and horn are inoperable, the rear safety switches are gone and the wires are spliced together, and the clean out plugs are frozen in. On a positive note, the hull looks like it will buff out, the courtesy lights and stereo work.
 
Some of the switches not working sound like a ground wire bundle isnt hooked up to the battery correctly. I have about 6 or 7 ground wires that all merge into one lug that goes on the ground on a battery. If they are not plugged up the dash and switches dont work. Mine is an 08, the model after yours but if u need me to I prob can get u a pic!
 
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