AR230 Engine Oil Question

[Nate Fallow]

Ok, you guys have been very helpful thus far in answering my questions so I thought I'd throw another one at you. I'm still looking at buying this AR230. I knew the boat had been sitting for about 3 years so I wanted the marina to change the oil in the motors before they water tested it. Well, not knowing how temperamental these engines are to oil I probably would've been better off not having them change the oil as they overfilled the motors when they did the change. Supposedly the starboard was worse than the port side. They claimed the started it up in the lake, hit the throttle and quickly noticed the starboard motor was smoking. They shut that one off and trolled back on the other and then pulled the boat out. It is currently being examined by a mechanic who is very knowledgeable when it comes to jet boats, at this point the mechanic claims that the motor is fine. I want to believe that as I'm getting more and more pumped by the day to do some wakeboarding but I am also terrified that it totally screwed it up. I know there have been a bunch of posts about oil level but I haven't come across one that speaks specifically to engine damage and wondered if anyone has an opinion?? Thanks, Nate

 

[buckbuck]

The only thing I recall is that it soaks the air filters with oil. They will need replacement. I don't recall any damage to engines but perhaps others will respond.

 

[Nate Fallow]

Well, new development............turns out the starboard side motor has low compression. The mechanic says that it is from the boat sitting unused and not from the oil overfill. So the boat owner is paying to replace that engine before I buy it....that part is pretty sweet. However, now my mind is spinning on as to when the other motor will go...or is this just a random occurrence isolated to that motor because of sitting around. Does anyone have any thoughts on that gibberish? TY!

 

[itsdgm]

Well, new development............turns out the starboard side motor has low compression. The mechanic says that it is from the boat sitting unused and not from the oil overfill. So the boat owner is paying to replace that engine before I buy it....that part is pretty sweet. However, now my mind is spinning on as to when the other motor will go...or is this just a random occurrence isolated to that motor because of sitting around. Does anyone have any thoughts on that gibberish? TY!

Welcome @Nate Fallow glad that you found this site and decided to join.

I had an issue with lack of compression in one cylinder a few years ago. It was due to a stuck exhaust valve. My boat does sit most of the year with frequent startups during the off season. I’m not sure what your exact issue is. But i doubt that excessive oil would cause a low compression situation. Also, it might not be a bad idea to have them replace the spark plugs. They tend to foul easily and burning that much oil could easily foul them.

Any idea where they’re getting the replacement engine? Is it a used original or a rebuild ( who’s doing the rebuild)? That would determine if i would continue to peruse the purchase myself.

Good luck with the purchase. Hopefully the worse is behind you.

 

[Jgorm]

Let me guess, 3 had the lowest compression and 2 is also a bit low.

 

[swatski]

I'll just throw this in, as I'm a big wannabe for a MR-1HO boat, still, lol.

A good demo how awesome those MR-1HOs are, check out the drag race by @buckbuck - his 10,000 hours(?) twin MR-1HO 212 going head to head - drag racing a brand new 2018(?) 212 twin 1.8! lol.
https://jetboaters.net/threads/drag-race-old-vs-new.11498/

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[Nate Fallow]

Thanks for the responses thus far. As an update I just got off the phone with the broker and the engine is going to be replaced with a rebuild from TBS..I guess?? It comes with a one year warranty so that's good. The mechanic is gonna go through both motors, redo the oil change on the 1st one, new plugs, etc..so it should be all good to go...I'm super pumped now. I'm going to be calling the mechanic so do you guys have anything specific for me to ask him or have him do while he's in there making it happen?? Now is my chance to get everything tip top before purchase...Go team!

 

[Scottintexas]

Let me guess, 3 had the lowest compression and 2 is also a bit low.

whoops, didn't I just comment to you about this item this morning ???

@veedubtek @Neutron @buckbuck or any other engine guys,
is there a time frame on an engine sitting that will cause it to develop a loss of compression or is this more just a random/bad luck occurrence or an MR1 issue ??



.

 

[boudin]

is there a time frame on an engine sitting that will cause it to develop a loss of compression or is this more just a random/bad luck occurrence or an MR1 issue ??

Hard to say on timing, but I would say 1+ yrs with water sitting in the water box, and the moisture could cause the valve stems to rust... hence stuck exhaust valves.

They are not difficult to unstick, and that should always be the first route. Involves pulling the valve cover, cams, and buckets, some WD-40 down the valve guides, and tapping on the valves with a brass punch. Attaching a leakdown tester to the cylinder will show you you were successful in unsticking. Once fixed, reassemble and run the snot out of it for a couple of hours.

Second option would be to pull the head and take it to a machine shop that rebuilds heads. Third a rebuilt head from SBT. Final (nuclear) option would be a replacement SBT motor.

Keep in mind with that 1yr SBT motor, YOU will be responsible for labor charges and one-way shipping to replace should the engine fail. The warranty will only get you a replacement motor, not the labor to actually swap the motor out.

-Greg

 

[bronze_10]

My boat sat on an in door storage rack from the end of 2009 to the start of 2015. We have had no issues what so ever!

 

[buckbuck]

@Scottintexas Your question is out of my league. I'm just an electrician.
@swatski ...10,000 hours!?...Just 500 hours on my boat. But I agree with you. The old MR-1 boats can hang with the big boys. It feels good.

 

[Jgorm]

I have pitting on the exhaust seats on 2 and 3. 3 had a 50% leak when the shop tested the heads off the engine. 1 and 4 look great. I suspect this is common these days on these engines. 3 out of 4 mr1s I've tested in the last year's had this issue with low compression on 3.

 

[buckbuck]

@Jgorm I have really enjoyed reading and watching your adventure on the boat you are rebuilding. I envy your abilities. Can you elaborate on why you feel this is common for the MR-1 motors?

 

[Neutron]

whoops, didn't I just comment to you about this item this morning ???

@veedubtek @Neutron @buckbuck or any other engine guys,
is there a time frame on an engine sitting that will cause it to develop a loss of compression or is this more just a random/bad luck occurrence or an MR1 issue ??



.

Its definitely not a time issue, but bad luck.
Moisture in any cylinder when laid up will ruin the walls and when you start up it grinds down the rings..... then loss of compression happens......
Fog it heavy if being laid up

@buckbuck , inner cylinders tend to get hotter by being sandwiched between two other hot cylinders. Could make them run leaner also making more heat .just a guess on my part though.
.

Older vtwin jap bikes with a carb for each cylinder. The rear cylinder would have a fatter (richer) jet to help keep the heat down. The rear cyl would be hotter by design because no air hitting it.
Richer is cooler leaner is hotter

 

[swatski]

@swatski ...10,000 hours!?...Just 500 hours on my boat. But I agree with you. The old MR-1 boats can hang with the big boys. It feels good.

Okay, so I exaggerated a bit... lol.

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[Bruce]

I just got off the phone with the broker and the engine is going to be replaced with a rebuild from TBS..

Members have had positive and negative experiences with SBT rebuilds. There is very little documented experience with 4 stroke engines. It was common for a 2 stroke repacked with an SBT rebuild to suffer another failure. This may have been caused by failures to repair the oil injection or carberator issues that likely caused the initial failure.

Personally I would walk away and look for a boat with good engines unless this is an incredible deal.

 

[Neutron]

Members have had positive and negative experiences with SBT rebuilds. There is very little documented experience with 4 stroke engines. It was common for a 2 stroke repacked with an SBT rebuild to suffer another failure. This may have been caused by failures to repair the oil injection or carberator issues that likely caused the initial failure.

Personally I would walk away and look for a boat with good engines unless this is an incredible deal.

We used to call them SBT Bombs because they would always blow up. We would joke that at least their posters were great to hang in the shop..
Then they got their crap together cause they now build good engines 2 or 4 stroke.
They also own Watercraft Superstore and sell tons of stuff now.
I have personally installed approximately 30 SBT engines or cylinder heads with no issues. I would use one in either of my crafts with no worries.

*****they will buy cores from anyone just to let you know in case you have an old motor kickin around******

 

[Bruce]

@Neutron, I have tried to invite SBT to participate in our forum several time.

If you happen to know someone there could you pass the invite along?

I have never purchased anything from SBT and try to be objective in posting about their engines. I am glad to hear that you have had a positive experience. I have a local mechanic friend who mentioned he uses them as well.

 

[Neutron]

@Bruce , i will deffinitly pass along your invite. I need to call them about a diagnostic scanner. And i will see if i can get a contact for you.

 

[Bruce]

@Bruce , i will deffinitly pass along your invite. I need to call them about a diagnostic scanner. And i will see if i can get a contact for you.

Thanks. I believe SBT would be a valuable addition to the forum. They may have had a bad experience with forums asking for money. All we ask for is participation.