MR1 STBD engine - series of problems

[svana]

Well...I think I've been bitten by the repair bug this season. After all my other nonsense earlier this year, I've got a series of symptoms going on now that have put my 08 SX230 out of commission until they're fixed. Issue is I've got so many symptoms/issues it's hard to sift through them all. I've tried to list all the symptoms/relevant occurrences below and hope I can get a little bit of help towards some clarity on how to approach things.

Most simplified/important issues:
Nasty rattle in STBD engine
STBD engine overheating
Both engines absolutely drinking oil (no leaks/symptoms found anywhere in engine bay)


Timing/further detail:
Engine rattle
If I’m really thinking back I think there’s been some level of this rattle for quite some time now although not as pronounced. I usually turn both engines on one after the other (starting with stbd) so I’ve always thought that’s their normal sound. Not until I’ve had to run them separately have I noticed how pronounced the rattle is on the stbd engine compared to the port. I’ve included a video for reference, but the rattling really isn't as pronounced as it is in person. I’ve got no real basis, but is it maybe a timing chain issue?


Overheating
This was first experienced halfway through our Bimini trip a few weeks ago. I definitely took on a bunch of sargassum on the way there - cleared it twice but who knows how long I was running it for. The second time it was absolutely jammed in there, took some force to pull everything out, but there were no issues yet. As stated, about halfway through the trip, I was running the motors a little past no wake speed, about 3000rpm when I first got the overheat indicator. Looked back, and was only getting water out of 3/4 pissers. Shut the engine down, checked the clean outs, made sure the lines weren’t clogged, etc.. After a few minutes I started it back up, punched the throttle and it was fine. I figured maybe the rpm’s were too high with how slow the boat was traveling resulting in the cooling water not traveling fast enough. On the trip back we got to the meeting point outside of the sands where it was a little choppy so I was feathering the throttle. At that point we got hit again with the overheating light. I again checked everything and after a few minutes started the engine back up and rode home without issue (kept it at roughly 6-7kr rpm for about 1/3 of the trip then increased to normal speed ~8k)

When we got home and were rinsing the boat off I pulled a tiny piece of sargassum out of one of the pissers. Not big enough to clog the line, but this indicates to me that some sargassum made it all the way through the cooling system…

I was originally honing in on the fact that I was only overheating at the lower RPM’s as a data point until yesterday when we took it out (tempting fate, I know) and we overheated at speed shortly after leaving our 15min channel. On the way back I was overheating even at idle/no wake, so there went that idea.


Oil loss
I check our oil levels pretty religiously as part of my pre-trip inspection. The engines of course are cold at this time, so the level is usually low as is expected. Recently however the oil levels on both engines have been seemingly very low. They were a bit low during Bimini so I topped them off with about half a quart between the two engines. Yesterday I checked the oil levels during the overheat and they were both showing bone dry after running for some time. I filled about a quart between the two of them and they were barely recording on the dipstick. Also there was traces of smoke(?) coming from the oil tank when I unscrewed the dipstick. The oil came out clean, albeit dark. I skipped last year so it’s been 2+ years since I swapped the oil and plugs, although we definitely don’t take the boat out as much as some here unfortunately… Also of note, there hasn’t been any evidence of an oil leak in the boat. A little sooty around the jets but seemingly not out of the ordinary.



Well…that’s the gist lol. I’d love to hear any ideas that folks may have. At this point I’m thinking about trying to get on the list for a local shop but everybody here is weeks out at least and I’m sure it’s going to be $$$…I’d love to avoid it if possible but it’s a little overwhelming at the moment.

https://imgur.com/BZakPv9

 

[Scottintexas]

a jet ski shop may be a good place for work,

I'd pull the thermostat and see if that caught any weeds, hard to believe weeds could make it past the strainer inlet and the nozzle,

I would also pull the impellers and then start the engines just to take any impeller slop out of the equation,

I don't have any advice on the oil except for to check it on the water or hose per them manual just to get a specific reading, before any issues checking on the trailer as long as it's always a little low is fine but now that you've identified a possible issue try to get detailed about it,

 

[Scottintexas]

also, maybe start a new thread "need an extra hand in Tampa" maybe there's a member that could help you trouble shoot in person,

 

[Scottintexas]

still kicking this around, just as easy things to check for the rattle,

confirm you engine mount bolts are still tight,


for the overheat,
can you make it overheat running on the hose ?
when using the hose do you clamp off the inlet line behind the line to direct all water to the engine and not out the nozzle inlet ?


also confirming you've watched buckbuck's mr1 cooling water expose'

.

 

[WREKS]

@svana Oil may be going into the cooling water. On my 2007-numbering from bow to stern-#2 is the high speed water pilot (pee). If you can do a compression check, that will indicate a possible compromised head gasket and the affected cylinders. Observe the plugs for wetness as they are removed!

 

[svana]

Thanks guys. I think my course of action will have to be:
Swap plugs (check for moisture)
Check mounting bolts
Test for overheat on just the hose

Unfortunately I don’t have any way to run a compression check.

Honestly I really don’t want to pull the impeller if I don’t have to, especially out on a work rack in the marina. I’ve inspected it and don’t have any wear or nicks, plus with the rattle being at idle the impellers wouldn’t even be moving, would they?

For the overheat hose situation, do you mind clarifying your question? Are you asking if I normally clamp when flushing or if I should try to flush while clamped?

 

[JetPowered]

Impellers are fixed to the engine via a coupler and are always turning when running. It’s easy enough to pull and inspect impeller on a work rack and it would go a long ways to checking off items on the troubleshooting checklist.

 

[Scottintexas]

For the overheat hose situation, do you mind clarifying your question? Are you asking if I normally clamp when flushing or if I should try to flush while clamped?

I was asking what your normal procedure is. I didn't realize you were on a storage rack.
You loose a lot of cooling water if you don't clamp off the inlet hose from the nozzle. You can still run the boat on the hose, the manual doesn't say anything about needing to do that but if you're trying to make both pissers work it makes it happen,

I would definitely pull the thermostat just to see if it caught any weeds,

the fact that BOTH engines are "drinking oil" makes me think you're missing something, I'd run them both on the hose per the manual and check the levels and check the levels before during and after an outing,

, plus with the rattle being at idle the impellers wouldn’t even be moving, would they?

your impellers are always spinning, the only factor in neutral is whether that nozzle gate is up or down, neutral the gate is half way, that's why people complain about forward/aft drift in neutral, it's hard to get the gate adjusted exactly half way,

 

[Scottintexas]

Does the engine smooth out at all at higher rpm's ??

 

[svana]

Thanks again - I've dug through the threads, I'll give pulling the impellers out a shot. Only thing they seem to not cover is how to physically remove the impeller shaft from the engine - does it just slide out once the housings are removed and that's why nobody mentions it? lol.

As for the roughness - it's hard to tell over the engine noise at higher RPM's.

Procedure-wise: ya it's a crapshoot as to what the marina actually does. I've got a little bit of hope in their process because in my vast amounts of time on the work rack this year I've gotten to watch them pull out many-a-boat lol. They do seem to flush the engines while they clean the boat up some and I know I'm not the only jetboater in the place. That being said, I wouldn't expect that they do much more than run water through the flush port. They did say if I had salt away that I could leave it out and they'd use it as well - definitely been missing out on that and will have that ready for them in the near future.

This should be a completely different thread but I'm always at odds on tipping them for their efforts or not...between the fact that they've got direct control over keeping my boat running and tipping will give them extra incentive vs the excess of tipping culture IMO and the fact that they've crunched my Bimini in the past (amongst other things...), I'm torn.

 

[Scottintexas]

the whole unit (shaft and all) just slides out, when you put it back in you may have to rotate the shaft slight to get the splines to line up, I've done my 5 times and sometimes it just slides in and other times it's work,

I didn't realize the marina was flushing it also, probably better on the normal routine to not use a clamp, no sense in making it more confusing for them, I would probably make a laminated piece of paper that I could stick near the port, "flush proceedure, 1. engine on, 2. water on, 3. water off, 4. engine off just to make sure they didn't hydrolock the engine leaving the water on with the engine off,

for your testing it may be worth it to try to clamp it,

 

[svana]

the whole unit (shaft and all) just slides out, when you put it back in you may have to rotate the shaft slight to get the splines to line up, I've done my 5 times and sometimes it just slides in and other times it's work,

I didn't realize the marina was flushing it also, probably better on the normal routine to not use a clamp, no sense in making it more confusing for them, I would probably make a laminated piece of paper that I could stick near the port, "flush proceedure, 1. engine on, 2. water on, 3. water off, 4. engine off just to make sure they didn't hydrolock the engine leaving the water on with the engine off,

for your testing it may be worth it to try to clamp it,

Funny…I’ve literally got a decal with those exact instructions on the flush fitting.

 

[svana]

Bringing back the necrothread - unfortunately haven’t gotten to the boat since last summer till today. That being said, I think I found a bingo on the overheat (hopefully). The STBD thermostat was seized shut (on the left side of the photo). Gonna order a new pair of stats and pop em in. That being said, does this housing look like it’s been flushed out after every trip (we’re in saltwater)? Also, dummy me forgot to see in what orientation the weep hole was positioned. Does anybody happen to have that info?

Thanks again everyone, just gotta tackle the rattle now.

 

[Xsannz]

Bringing back the necrothread - unfortunately haven’t gotten to the boat since last summer till today. That being said, I think I found a bingo on the overheat (hopefully). The STBD thermostat was seized shut (on the left side of the photo). Gonna order a new pair of stats and pop em in. That being said, does this housing look like it’s been flushed out after every trip (we’re in saltwater)? Also, dummy me forgot to see in what orientation the weep hole was positioned. Does anybody happen to have that info?

Thanks again everyone, just gotta tackle the rattle now.

hmmm you make me want to run out and pull my thermostat housings now... my anodes and passages were clean and clear but the boat was sitting for 2 years in storage from the PO and I've never seen water out the pissers, might make that a today job its raining out.

as for your rattle, i too found this one rattled except my port side more than the stbd. i recently pulled my pumps and impellers and shafts out, and then ran up the engine, found out both my impellers had been changed to solas variants that were not even the recommended and were also really badly shot and worn hitting some pretty corroded liners, long story short once i removed them the engine sounded pretty good.

if you do remove the drive shaft and impellers, and you still have a rumble (not a rattle) or a rubbing sound then chances are your intermediate bearings and housing need a rebuild.

But by normal standard the mr1 engine is a rather rattly sounding engine, the timing chain isn't a quite system a lot like the old R1 engines on bikes from early 2000s (same design of engine), if it seems overly loud rattly still after the above, then i would pull the timing chain tensioner and either replace or try reset your ones sometimes they can get stuck with overheat. (again i am using my motorcycle knowledge here i used to race and rebuild the r1 engines).

but tbh before you do the above i would try solve your drinking oil issue, as one of the items that dampen the noisy chain tensioner is actually oil...

 

[svana]

hmmm you make me want to run out and pull my thermostat housings now... my anodes and passages were clean and clear but the boat was sitting for 2 years in storage from the PO and I've never seen water out the pissers, might make that a today job its raining out.

as for your rattle, i too found this one rattled except my port side more than the stbd. i recently pulled my pumps and impellers and shafts out, and then ran up the engine, found out both my impellers had been changed to solas variants that were not even the recommended and were also really badly shot and worn hitting some pretty corroded liners, long story short once i removed them the engine sounded pretty good.

if you do remove the drive shaft and impellers, and you still have a rumble (not a rattle) or a rubbing sound then chances are your intermediate bearings and housing need a rebuild.

But by normal standard the mr1 engine is a rather rattly sounding engine, the timing chain isn't a quite system a lot like the old R1 engines on bikes from early 2000s (same design of engine), if it seems overly loud rattly still after the above, then i would pull the timing chain tensioner and either replace or try reset your ones sometimes they can get stuck with overheat. (again i am using my motorcycle knowledge here i used to race and rebuild the r1 engines).

but tbh before you do the above i would try solve your drinking oil issue, as one of the items that dampen the noisy chain tensioner is actually oil...

Ya, I’m not so confident in my tstat prognosis. The more I thought about it and read on it the more I realized they’re usually shut until they heat up. Meaning my port side was actually seized open, not the other way around. I boil tested em and they actually operated as they should after I washed the salt off some. I ordered new ones anyways (surprisingly pricey), cleaned out their housings and will have to keep an eye on it. I’m naively hoping that 9 months out of the water sort of dried out whatever might be blocking and will pass. Going to at least have an IR thermometer on hand to see where the temp varies from port to Stbd if I get the overheat warning again. Also didn’t hear the rattling anymore when I started it up yesterday - but again I’m assuming it’s something that’ll come back after the first run of the season. I do have new plugs and oil/filters on the way though as well. Gonna try and watch the air show from the boat on Sat, I guess we’ll see how it goes. Gonna at least try to run the engine on the hose for a little while and see if I’m still getting the warning.

As for the rattle, I know they are generally pretty chattery, but the Stbd rattling more than the port was what was making me pay attention to it.

 

[svana]

Just wanted to provide an update for anybody who might have a similar issue. I took an IR thermometer with me the last trip to get an idea of where the temp variances were between the port and stbd engines were and I was getting different readings around the oil reservoir and in some of areas of the exhaust. The motor block was mostly the same between the two. Latest steps were as follows:

1) I replaced the series of hoses connecting the Y intake to the manifold to the engine as one of the hoses was a little kinked. The hose I utilized was nothing special, standard engine hose (overpaid at west marine just so I could have a “boat hose” for peace of mind lol…ugh) was a good bit thicker and stiffer so it will be much less prone to kinking over time.



2) Replaced both thermostats (I don’t believe this was a major factor, but again - peace of mind)

3) Cleaned out the oil cooling port hard with a dremel and wire wheel bit and vacuumed all the crap out.

4) Changed my oil and spark plugs.

Took her out for a shakedown run yesterday and what would you know - no overheating! Ran her around 8-9000rpm for 20-30mi without so much as a hint of overheat. I’m not certain which of the above steps solved the issue but the hose change was the only thing done to the STBD and not the port side. I’m wondering if it was the old oil, why the port wouldn’t overheat too. That being said, it hadn’t been changed for 2+ seasons and the oil was BLACK! I figured since we didn’t drive the boat as much as others here it wasn’t as urgent, but I do believe that was a primary culprit. It is definitely now on the annual maintenance list. CHANGE YOUR OIL AND PLUGS, FOLKS!

…oh and I snapped a steering cable on the way back to the marina lol