Problems with brand new Mercruiser 383 MPI

[AC-1]

Rodgerdog23, I am very sorry to read of your dilemma, but have been enjoying this blog. I feel guilty but I’m sure it will come together for you. What I have enjoyed the most is how everyone who has been responding is doing so in a professional and VERY respectful way. I commend all of you. Best of luck, and thank you.

 

[Rogerdog23]

That’s awesome AllDodge. Great idea. AC-1 I’m glad there is some good entertainment at least. While beyond frustrating, most people aren’t lucky enough have a boat to be frustrated about. Not a real problem just bad timing as boating is my family’s favorite activity and I tried avoid all of this by buying the best one Mercruiser offered and repowered in March knowing things get crazy in summer. This forum has been amazing and very positive to your point. Hopefully we get good news today.

Alignment and gimbal should be good now. Going from 24” props to 22.5”. Fuel burn has been about 17 gph at 3900 rpm and 30 mph. Place your bets on what will happen everyone...

I’m hoping it goes above 5200 rpm as the alignment and gimbal got some improvement and obviously I should get more rpm from smaller props. Would prefer to go up in props not down. A guy can dream...

 

[muc]

Don’t know what to think about the gear lube. I haven’t seen the racing lube but was told that it would be a dark amber color. I call Volvo lube clear. Maybe someone who hasn’t seen Volvo lube would call the racing lube clear? Both are more expensive than what is recommended for your drive, so don’t know why they didn’t use the high performance.

The only thing that can be visually inspected on a coupler is the part of it that can be seen with the gimbal bearing and seal removed. So I have no idea why an engine pull would be needed. Only way to protect yourself is to have documentation of the gimbal bearing needing to be replaced and going forward make sure you follow your owners manual having the alignment checked. I didn’t feel your gimbal bearing so I don’t know if you need to worry.

I’m in MN and don’t see water temperature affect engine temperature much at all. It does make a difference in exhaust manifold temperature and how long engine oil takes to warm up.maybe it’s different in the NW?

Did they get your Mercathode squared away?

 

[muc]

On changing two things at once, I agree it’s not perfect. But when you choose a dealer that isn’t based on the water it to be expected.

 

[Rogerdog23]

Thanks, Muc. I’ll see if they can save the gimbal for me and have my Dad look at it...he was a pro. Interesting on the coupler will ask more questions. For alignment checks are you saying do the grease on the tool and see if the coupler looks okay when you remove it or something different?

Sounds like AllDodge can stick a finger in the new race line and prove it’s clear. Lot of confusion on that topic including from Mercruiser due to all the changes.

I’ll remind them on the merchathode. This dealer is on the water but MC wants them to try smaller props.

 

[QBhoy]

Hi
just before I go off on a theory or two....

what oil are you using in engine ?
what gear ratio is the bravo ? Usual 2-1 approx ?
ive read this a few times now. What exact model is it ? I work in kgs, but from what I gather you say it’s over 6000 lbs dry so over 3000 kgs dry ? Is it really that heavy ? That’s almost twice the weight I’d expect a North American 24ft boat to be dry. I’d have thought 2000 kgs would be the average for a 24ft cruiser from over there. Maybe less dry.

Cheers.

 

[Rogerdog23]

QBhoy: Looked again on weight and saw the same model as mine but a few years newer weighing in at 5600 pounds dry.

 

[Rogerdog23]

And now, the moment we’ve all been waiting for...

Got the boat back and wasn’t able to give it the thorough running i wanted due to rough weather but did find a couple smooth places to give it a quick go.

I turned the key and the engine started really easily. My wife and I immediately looked at each other with raised eyebrows and said “it sounds totally different” at the same time. Not sure why it would sound different but it did from the second it started in neutral and continued to sound different all the way home. Maybe that alignment was really messing with things.

Running new 22.5” props i got 5310 rpm at WOT. That’s 400 more than i was getting with the old props and before the engine was aligned properly and gimbal bearing was replaced. 41.5 mph. Cruise at 4000 rpm and 30mph burning 14.1 gph.

The hole shot is incredible. Obviously going down 1.5” in props helps there but i think we are getting more performance outside of the prop change. It is a force to be reckoned with just like the reputation of the 383.

I need to run it more but that is what i know for now.

Now the bad news: Got back to the buoy and put it in neutral. Noticed it was idling high...1,000 rpm. Put it in reverse for a few seconds and then back to neutral. Still the high idle and also a grabbing noise like it didn’t get all the way out of reverse (but wasn’t still turning the props). The dealer tested on the hose Thursday after realigning the engine and it was good until they put it in reverse and it got stuck there. Said some small plastic piece on the shift cable was broken but were able to find another one and put it on....problem solved they said. They also water tested the boat yesterday before giving it back to me and evidentially didn’t have a problem. Not sure if there is an easy adjustment I can make to get the idle down and fully shifted into neutral? I want to go play with the boat today and learn more!!

 

[alldodge]

Sounding different I wouldn't think that would come from the bearing, maybe its now hitting on all 8 cylinders

The high idle if not a miss-adjusted throttle cable, should all be taken care of by the IAC and ECM.

 

[Rogerdog23]

Interesting. I don’t think they did anything to the engine just the alignment and bearing. It idled fine until I ran it home (45 minutes) and put it in neutral. Going to the buoy dead slow it idled nice and low. Put it in neutral and that’s when it went to 1k rpm idle. That and the noise like it didn’t come all the way out of fear.

 

[Rogerdog23]

Update: Just went to look at it. Started it up and no noise and low idle around 600 rpm. Put it in forward for a few seconds and back to neutral...no problems. Took a lap around our bay and things were fine. Not sure if this is a good thing or will turn into an intermittent problem but for now I’ll take it.

Hope to run the boat thoroughly tomorrow as weather will be better. If I’m still high on rpm will ask Mercruiser about going back to my 24” props to see if they perform any better than before the alignment and gimbal work was done.

 

[QBhoy]

And now, the moment we’ve all been waiting for...

Got the boat back and wasn’t able to give it the thorough running i wanted due to rough weather but did find a couple smooth places to give it a quick go.

I turned the key and the engine started really easily. My wife and I immediately looked at each other with raised eyebrows and said “it sounds totally different” at the same time. Not sure why it would sound different but it did from the second it started in neutral and continued to sound different all the way home. Maybe that alignment was really messing with things.

Running new 22.5” props i got 5310 rpm at WOT. That’s 400 more than i was getting with the old props and before the engine was aligned properly and gimbal bearing was replaced. 41.5 mph. Cruise at 4000 rpm and 30mph burning 14.1 gph.

The hole shot is incredible. Obviously going down 1.5” in props helps there but i think we are getting more performance outside of the prop change. It is a force to be reckoned with just like the reputation of the 383.

I need to run it more but that is what i know for now.

Now the bad news: Got back to the buoy and put it in neutral. Noticed it was idling high...1,000 rpm. Put it in reverse for a few seconds and then back to neutral. Still the high idle and also a grabbing noise like it didn’t get all the way out of reverse (but wasn’t still turning the props). The dealer tested on the hose Thursday after realigning the engine and it was good until they put it in reverse and it got stuck there. Said some small plastic piece on the shift cable was broken but were able to find another one and put it on....problem solved they said. They also water tested the boat yesterday before giving it back to me and evidentially didn’t have a problem. Not sure if there is an easy adjustment I can make to get the idle down and fully shifted into neutral? I want to go play with the boat today and learn more!!

might be wrong and these 383 maybe have a higher limiter, but I assumed they might limit before that. Did it beep on the buzzer ?

 

[Rogerdog23]

Shift and high idle problem is back. If you put it in neutral and turn it off then back on the shift noise and high idle goes away. Too weird. Thoughts welcome.

 

[muc]

When it has the high idle, go back to the engine and try to close the throttle at where the cable connects.

 

[Rogerdog23]

Thanks, Muc. You mentioned the upper bearings in the outdrive could have been damaged. What would you say to someone who doesn’t believe this is possible because the I joints have flex in them and stress couldn’t be transferred that far from the misaligned engine?

Also what kind of noise would the bearings cause? Would you hear it from the engine compartment or back on the transom / swim step?

 

[muc]

My comment about ujoints and bearings was assuming alignment was causing all your problems. I don’t think it was, so I wouldn’t worry to much about it.

What i would say to those people. Ujoints are designed to flex at a specific place. They aren’t designed to support the load that occurs when the engine is way out of alignment. The bearings in the drive are designed to support a load, just not that much.

Bearing noise is best east described as chatter/rumble. Easier to hear outside the boat.

 

[Rogerdog23]

Thanks Much. I’m hearing a noise from the swimstep that I haven’t heard before and is hard to describe. A bit whispy almost like a commercial paint shaker but not nearly as loud or violent as that. Not sure that makes any sense but that’s the best I can describe it. Can’t hear it in the engine compartment.

 

[gobuck]

fixing the engine alignment made that much of a difference in performance???

 

[Rogerdog23]

You were right On the throttle Muc. Dealer fixed it today and it felt and sounded really nice on the ride home. No more high idle and no more shift issues. I still hear a sound on the swim step coming from the outdrive but I’ll put that on hold for now. Mercruiser is good with me going back to my old 24” props and seeing what happens. Will try to do that on Saturday and report back what I learn. Any ideas on what going from a 22.5” to 24” props should do to rpm and top end speed with the bravo 3 duo props?

 

[AC-1]

Waiting for an update????