Engine Trouble

[dnicholas47]

Sorry I’m advance for the long post, but I figured I would give as much info as I could. You can decide what of that info is worthless.

I had changed the oil and plugs on June 29. I ended up getting over 5 quarts out of each engine, but I only put 4 back in. I used Yamaha oil and filters just to be safe since I’m still under warranty. The boat ran on great on vacation the next week with no issues. Oil levels were fine.

Fast forward to 3 weeks ago, first time Boat had been used since July 6. Starboard engine ran rough at idle, but nothing else noticeable at speed. Oil level in both engines was on the lower side, but still in the good range. I chalked it up at the time to maybe mixing marina gas with Kroger fuel at home. When I filled it up the next time I made sure to add Marine Sta-bil.

We went out again Sunday and the rough/loud idle was still there. Port side was fine. I normally have to push the starboard throttle farther forward to get the RPM’s to sync and that hadn’t changed.

But by the end of the day, things got worse. The RPM’s on the starboard were now much higher and I had to push the port throttle to sync. At idle the sound was worse and starboard RPM’s were higher (normally in no wake and idle they are synced, its only mid range you have to compensate the throttles).

When I got off the boat to get the trailer I noticed one of the pee nozzles had the stream of an 80 year old man with prostate issues compared to the other one. I did forgot to check the oil levels when we pulled out since we had several kids with us and I got sidetracked.

I was planning on taking it to the dealer, but wondered if you guys had any ideas since I have seen so many horror stories on here about dealer service centers? Or since I am not so mechanically inclines at least something to suggest to the dealer that may make it easier to get to the root of the problem.

 

[MidnightRider]

When I got off the boat to get the trailer I noticed one of the pee nozzles had the stream of an 80 year old man with prostate issues compared to the other one

This ^^ almost always true for my boat at idle, once I hit the throttle they both have good strong streams.
First thing I'd do is pull all the spark plugs and look for abnormalities on the plugs - wet, burned, etc.

 

[swatski]

Some dealers are great, it really depends.

I would start by inspecting the pump. If already on the trailer, stick the phone through intakes, cleanout and look through the steering nozzles - any obstructions, even small. Is the impeller damaged? The cooling water intake is inside the pump - with a whitish grate, is it clean?
The 1.8s are not as sensitive to oil overfill as the MR-1s so I doubt that is the major issue, but it could be and your plugs may be fouled. Changing the plugs would be #2 on my list.

--

 

[Bruce]

I suspect that you have an issue with your starboard jet pump causing the rattle to occur in the pump and RPMs to be higher on that pump due to cavitation.

Have a look in the pump.

 

[Bruce]

One way to test would be to pull the starboard pump and see how the engine sounds.

 

[Scottintexas]

have you owned the boat since new ?

since it ran good for a week after the oil change I would guess that didn't have anything to do with it but I would check the oil level the next chance I get to confirm it's still ok,
5 qts seems like a lot but i'm not familiar with the 1.8 so maybe that's the normal amount, if you had an excess of oil I'd worry that it might have gas mixed in with it and you had a bad injector,

My first thought is your having cavitation, I would check from underneath and look up through the grate and maybe even remove the impeller/shaft since it's a pretty easy job to make sure it's clear, if you don't see anything obvious run the engine without the shaft to see if it's running smooth,

If the engine runs smooth without the impeller then you either have an impeller issue or air intrusion and if it's not obvious put it all back together and water test it again, maybe whatever was causing a problem fell out and it will run fine,

if your back on the water with the same symptoms then you'll have to decide

 

[swatski]

5 qts seems like a lot but i'm not familiar with the 1.8 so maybe that's the normal amount, if you had an excess of oil I'd worry that it might have gas mixed in with it and you had a bad injector,

5qts is a lot! Especially talking the "extractable" volume...
But if the OP pulled that amount out of both engines (?) may be unlikely to be the only cause, could be somehting in the pump and spark plug fouling?

--

 

[haknslash]

Yes 5 qts is a lot to extract out!! 1 too many qts not to mention what you couldn't extract out. Who filled the oil prior to your oil change? Previous owner or dealer?

When you say rough idle is the engine struggling to keep idle or are you just hearing things?

Stream strength from the pissers won't look strong at idle. It isn't until you're applying thrust when the stream begins to look strong.

 

[dnicholas47]

I am the second owner. Previous owner (a member here) did the last oil change about a year before I did the one in question. I actually started a thread here because I was concerned about the amount. https://jetboaters.net/threads/oil-change-question.18449/

I did not check the pumps, mostly because I thought that if there would be cavitation I would have noticed it at speed. The only time I noticed any symptoms was at idle until just before we took the boat in for the day. But it had been idling rough for 2 outings. But I did just think that I replaced the intake grate the same day I did the oil change. All I did was unscrew it and rescrew in the new one. Could that have done something?

I can try and get down to where we store it later this week, unless you guys think I am better off just making a dealer appt now.

 

[Scottintexas]

I wouldn't take it to the dealer unless you have supreme confidence and trust in them,

time is money and your time is worth money along with how much time can spend either troubleshooting or waiting on a dealer to look at it/fix it.

thinking more on this,
I doubt the intake grate is an issue since it ran fine for a week afterwards, something would have let loose and that isn't normal enough to suspect yet,

I would check the oil again , look at the impellers and silicone to make sure nothing obvious looks wrong, pull and note or even change the spark plugs again,

take it to the lake and see what it does, especially check the oil on the water while warm and see how the indicators are flowing

the low flow indicator makes me think something is up with cooling water supply from either low pumping from the impeller or a blocked intake screen,
the rpm's make me think plugs

 

[djetok]

you might check your air filters as well. If it was previously over filled the filters could be wet.

 

[dnicholas47]

I did pull the filters when I winterized last year to fog the engine and they were dry for whatever that’s worth. But I will check again. Thanks guys!

 

[Gym]

I'm not familiar with the 1.8s but anytime you overfill the oil it usually has to go somewhere. Either a breather or the air box. I would open both air boxes and check for oil intrusion and check both filters for oil or dirt. You may also want to try running with no air filters to see if that has any effect.

 

[Matt Phillips]

Interesting. I did my annual oil change last weekend and only got 3 quarts out of the starboard and 4 out of the port. the Dealer did the last oil change at the end of the season. I put 3 back in the Starboard and 3.5 in the port, and best I can tell both are OK on oil. I also always check my oil while the boat is sitting in the lake, or I've confirmed the trailer is level.

As others have stated, I'd check the plugs. These engines can be finicky with older plugs. As a general rule, I change mine annually in the spring before initial start.

A couple of things I've noticed this year that I haven't in the past:

1. On cold start they both are finicky. Many times they will start, run rough for 5-10 seconds, maybe die, or smooth out and fin fine. They will alternately start right up and run normally. I will ask the dealer to check this out at the end of the season
2. At random times, one engine will not start when warm. It will crank for 5 or so seconds then stop. Then after waiting 2-3 seconds, it will fire up again after trying to start. I've seen this 2x on the starboard this summer, and 1x on the port. It is almost like they have vapor locked or something. Again, I haven't noticed the pattern to be able to troubleshoot it.

These have all been at 6230' elevation with Marina fuel and Stabil added to every tank. I'll be at a lower lake and will try a higher octane fuel the next tank to see how it changes.

1. For the last 1.5 seasons, the starboard has idled louder/rougher than the port. The port is so smooth that I hardly feel any vibration in it whereas the starboard is inherently rougher. As soon as any thrust is applied, it runs quiets down. Again, the dealer said this is normal when it was in for warranty work last year.

 

[Cobra Jet Steering LLC]

I would not be concerned about the water coming out the pisser, too many things that can cause that and mean nothing to the engine even bugs build nests in the tubes. noise does mean less water in the water box but when the engine is just starting up again it means nothing until the mufflers get the correct amount of water inside them. less water more noise. I would only be concerned if the noise did not lower once the boat was running for a minute or two. Idle can be a number of things like plugs, or air box or throttle body position. Again nothing that would be a big deal . I doubt you have any real issues to be worried about really .

 

[Bruce]

The RPMs going higher at the same throttle and reduction in cooling water flow both are signs of cavitation.

 

[dnicholas47]

Thank you again everyone. I will pull the pumps and check the plugs ASAP. In a perfect world I can get on the water this weekend to see if that solves it.

 

[dnicholas47]

Update on this thread and a couple more questions. Ended up taking it to the dealer last year as I couldn’t find a damn thing that could cause it. They said it was the throttle cable being bound up by perfect pass (an out of warranty fix of course), and sent me home good as new. Weather had turned by then so I took them at their word, got ripped off on winterization since they had it there working on it anyway, and took the boat straight to storage when I picked it up (with a completely dead house battery, but that’s another story for another time).

Fast forward to yesterday when I hooked up the (new) batteries and started it up. Same problem right out of the shoot. (2400 rpm starboard at idle, 1300 port). Taking what they said the problem was, I loosened the perfect pass dial. Problem solved for 4 seconds until it tightens itself. So then I loosened the throttle cable at the throttle stop and that fixed it, but the throttles are totally not synced. If I have them hitting the throttle stop at the same time I get starboard high idle. Thoughts?