Newbie says HI, and has questions about 1998 Sportster 1800 project

[coletrain777]

So...
I just purchased a 1998 Sportster 1800 project that I have some questions about. First off, I am a total newbie when it comes to these type of boats (or 2 stroke engines in general), but I am very mechanical and have a well equipped shop. I purchased the boat from the owner with one engine removed (but still together as a longblock). The owner said that he had stored the boat for the winter, and when he went to fire it up in the spring the left engine wouldn't turn over. He took it to a local mechanic who found that oil had filled both cylinders causing the boat to not be able turn over until the spark plugs were removed and the excess oil blown out. Instead of fixing the problem the mechanic suggested that he just purchase a reman engine to replace the problem engine Anyway, he has two young children and decided to wait and do the project over the winter... which never happened. So I bought it from him as a very nice, complete boat with the one engine removed. Now for my questions:

1. What are the probable causes for the oil leakage into the cylinders? I did some searching and found that several people online complained of a similar problem after their boat sat for an extended period of time, but I never found where someone stated what the solution was??? I don't mind tearing into the engine and just replacing all gaskets/seals, but what should I be looking for?

2. What things should I check on one/both engines to ensure that I have good/serviceable engines? I would imagine a compression check would be at the top of the list... what else? As I said, I am a newbie to these engines.

(The engine that is still installed fired up right away when I pressed the button... I ran it for about 3 seconds and shut it off)

3. Any other advice for me before I dive in? I have the service manual, what else should I get. I will be doing all the work/maintenance myself, going to the dealer is not an option. I don't mind a learning curve, just please point me in the right direction.

4. What is the technical designation for my 98' 1800 Sportster??? Why is there so much info on the speedsters, 1800 challengers, but not the 1800 Sportster???

Thanks in advance, really excited about finding this forum/community! Looking forward to becoming an active member in the near future. Thanks Cole

 

[Dr Honda]

Since the engine was removed, and a "Project" I'm assuming that you got a good deal on it.

OK... here's the deal.... on a seadoo engine, the center of the engine has a set of gears, that drive the Rotary valve. Those gears are lubed with oil from the injection tank. It basically just keeps them submerged in oil. When the seals start to wear... the oil will leak past, and fill the engine. This is common on an engine either using the wrong type of oil, or one that just has a few miles on it. Chances are... that engine is perfectly fine. Once you purge out the oil... it probably won't become a problem again until it sits over winter. And... in that case... knowing they leak... all you do is put a clamp on the feed hose. I'e seen engines with slow leaking center seals run for 3 or 4 more seasons before needing a real rebuild.


If it was my engine... I would purge the oil out, and check the compression. (you can do that out of the boat) If you can get more than 135 PSI... I would just put the engine back into the boat, and go run it. If it's lower than that... it's time to do the rebuild.

Let's go over your questions:

1) See above.

2) Really... a compression check is the single most important thing a home mechanic can do. A leak down is next... but it takes some specialty tools, and effort to do. A fresh seadoo engine should be 150 psi... anything 135 and higher is fine... anything lower than that... you will have running issues, and short life. (time for a top-end before it melts down, and takes out the bottom half too)

3) Unless the previous owner told you exactly what oil he was using... I would drain the oil system, change the filters, change any hoses that are overly soft, or hard... and refill it with an approved API-TC oil. NEVER use a TC-w3 outboard oil. Also... ask us questions... we will help.

4) That's because they only made it for 1 or 2 years. They made the 14.5' boat in multiple variations for about 11 ~12 years.

Good luck, and enjoy your stay. :thumbsup:

 

[coletrain777]

Doc,
Thanks for the quick (and informative) response! I will put the starter back on it, hook the starter up to power, and run a compression check on it. I have leakdown test equipment as well, I just wasn't sure about leakdown result testing due to it being a 2 stroke engine (never worked on a 2 stroke). Your thoughts about the engine being just fine are the same thoughts I had as well, and I don't mind tearing it out if I do need to put in a set of Rotary Seals later on.

As far as the oil goes, where is the best place to purchase and do you have a recommended brand (not trying to start a debate... just wondering)?

Are the Sportsters a good choice for basic family fun that could include tubing and novice skiing? Wasn't sure about how they did pulling a skier up based on holeshot performance.

As for getting a good deal, I think I did really well. The boat is EXTREMELY clean (looks almost like new inside and out) and has been covered it's whole life. It came with a very nice trailer (I would imagine factory) and factory boat cover and bimini top. I paid $2,000 for it which I normally would have tried to talk the seller down from, but the boat was so clean I just gave him what he asked. All in all, I think we are going to be in to a nice boat pretty cheap, and my 3 yr old boy LOVES IT!

 

[drtyhatch]

congrats on the new boat. I bought a 1998 seadoo sportster 1800 2 weeks ago and found out quickly that there is very very little information on them out there. I had the problem of buying a boat with a bad mpem which is now discontinued through seadoo and almost impossible to find used. I ended up having to use 2 separate electronic boxes out of 1995 xp ski's. Looks like us sporster 1800 owners are a small small group.

 

[Dr Honda]

I paid $2,000 for it which I normally would have tried to talk the seller down from, but the boat was so clean I just gave him what he asked.

DAM !!!!! you stole it. (good for you)

Yes, a leak down is almost more important in a 2-stroke than it is in a 4-stroke. In a 2-stroke, you are pressurizing the entire engine, and looking for case, and seal leaks. If you have a case leak... you can melt an engine by running it lean. But to do it... you need to make up plates to cover the exh, and int ports. Leaking center seals don't cause a lean run... they cause the situation you have now.

I personally use SeaDoo XPS semi-sythetic oil. If you dealer is nice... they will give you a case discount. (3 gal)

That boat will be a lot of fun, once you get it up and running. I just sold the boat in my avatar, and my 4 year old was crying as it left. We had a new baby, and I figure it wasn't going to get much use this year. BUT... I will start looking for an Islandia that needs a little work this fall. (I still have JetSkis in the garage to play with)

 

[coletrain777]

drtyhatch - glad to hear there is another sportster 1800 owner around. Yeah, when I decided to buy the boat I did some searching on the net and your posts about the MPEM problems are the first I found. I had a lengthy discussion about the electrical system of the boat and he assured me that I wouldn't have any problems there... and I don't seem to (knock on wood). Hopefully you get her all sorted out and on the water in no time.

Dr Honda - I did a compression test today and... these engines must have Very low hours on them. The engine that is currently out of the boat had 148 psi on one cylinder, and 146 psi on the other. I think I will be OK to run with this one... hopefully. I will check the compression on the installed engine in a few minutes and report back in a little bit.

1. Is there any way for me to monitor the severity of the rotary seal leak with the engine installed? If the leak is severe how will I know while I am out on the water? If it is fairly severe but not enough to hydro-lock the engine what other damage could take place from running it this way? I would just like to be able to prevent any problems on the water as we have to travel a pretty good distance to put in.

2. The other question I have is about engine mount shims? The shop that removed the engine did a great job of keeping all the hardware together and threading bolts back into their original holes. Every single bolt, nut, and misc fastener is there and accounted for except for engine shims. I have a hard time believing that they would have been so meticulous with everything but loose the engine mount shims??? Is it possible that my engine had no shims, just the mounts, plate/cradle, and the engine? If I do need shims I guess it wouldn't be a problem for me to make those... do I need the alignment tool the factory manual speaks of in order to do this the right way. I would like to go ahead and drop the engine in tomorrow, but I don't want to have to do the job twice or more because I didn't have the correct understanding of things.

Thanks everybody for the help and support so far, keep the answers coming!

 

[coletrain777]

I checked the compression on the engine that is still in the boat and it has 148 psi on one cylinder and 147 psi on the other...I guess this boat really did have low hours on it Does anyone have any guidance/info in regards to question #2 I posted above about engine shims. I really would like to put this other engine back in the boat but I don't want to risk putting it all back together and having it be slightly out of alignment (I would think that would be very destructive on such high rpm engines)?

 

[parrothd]

You need the alignment tool... SBT rents/sells them or have the dealer do it...Probably cheaper to buy the tool, last time I checked it was $150...


Just looked it's 75$ plus shipping to rent...

 

[chlarson23]

did you ever get your boat running? if not let me know cause i had this problem and was able to fix it with out purchasing any parts. let me know.

 

[LouDoo]

Just a suggestion, when addressing an old post you would be better off PM'ing the person who started the thread. Not noticing the date I just read through the whole thread to see if I could help.

Lou

 

[coletrain777]

Yes, we put the engine in ( no shims needed, I guess that's why there were none), and it fired right up and ran well. I ran the boat all summer like this and it performed flawlessly. I actually just winterized the boat this evening... looking forward to next spring and getting out on the water

 

[RFoster130]

Wow, great deal for $2000. Glad it all worked out for you.

 

[John in Valley Forge]

That is awesome. I paid closer to $5k for mine a few weeks after you and enjoyed the heck out of it over the summer.
No I am just yearning for spring to get it out again.