Ran amazing then shake no thrust

[MikeyArriva]

1989 Arriva 2050 Mercruiser 5.0 Alpha 1 Gen 1

Sooo I'm just throwing this out here, I can't find anything in the search. So I just changed out the bellows and shift cable.. Apparently I missed tightening the transom side of u joint bellows because it was still leaking. When I took outdrive off too see why it was leaking, it was full of gear oil. Thats when i gave up and took to marina. They said that i didn't tighten transom side of bellow enough and that yoke and seal were worn. So they fixed that. I put er in the water tonight for a test. No leaks, Idled so smooth at the dock and slow cruising out of the area. Put her up on plane, ran amazing for a few minutes and then could feel a shake. I slowed to turn around and it didn't seem bad, when i put the throttle down it would barely plane. I pulled the throttle back and it shook, I could see a little bit of smoke coming out around the outdrive. Oil pressure was good on gauge. When i put throttle down again almost nothing happened. Wind going in the opposite direction i had to keep it going. I ran just above idle back but saw a marina and headed that way. Could feel a shake to the dock then it shut down. I couldn't get it to fire up again. just kept rollin over. Finally a half hour later i got it to fire up to get to launch but it was shakin and spitting and stalled again. In 7 years I have never had a problem with this engine. Could this be multiple miss fires or some major issue I can't think of? Def seems to be in the engine. I don't know where to turn now

 

[Rick Stephens]

Probably should post serial number of engine.

Have you inspected contents of water separator?

What kind of engine maintenance you have done in 7 years of no problems. Carb rebuilds? Fuel water separator replacement? Fuel filters? Cap rotor sensor plugs replacements? Is the motor due for a tune up?

 

[alldodge]

Had good power, then shake, then see smoke and had to idle back because anymore power and nothing. Sounds like engine coupler

Next question, when was the last time engine alignment was checked? Should have been checked before reinstalling the drive

 

[nola mike]

Had good power, then shake, then see smoke and had to idle back because anymore power and nothing. Sounds like engine coupler

Next question, when was the last time engine alignment was checked? Should have been checked before reinstalling the drive

That's where I was going. Enough to get back to dock, hopefully enough to not overheat the engine severely, but continuing to drive and then no start...
Op, did the revs increase but the boat didn't go faster, it did the revs stay low when you hit the throttle?

 

[MikeyArriva]

Had good power, then shake, then see smoke and had to idle back because anymore power and nothing. Sounds like engine coupler

Next question, when was the last time engine alignment was checked? Should have been checked before reinstalling the drive

Yes also installed new gimbal bearing and checked alignment. I would certainly hope the marina did too before putting it back on

 

[alldodge]

If not coupler then prop hub

 

[MikeyArriva]

That's where I was going. Enough to get back to dock, hopefully enough to not overheat the engine severely, but continuing to drive and then no start...
Op, did the revs increase but the boat didn't go faster, it did the revs stay low when you hit the throttle?

revs stayed low. they came up a bit but not screaming full throttle. like it was trying to go but couldn't. got moving and big wake but wouldn't plane

 

[MikeyArriva]

Probably should post serial number of engine.

Have you inspected contents of water separator?

What kind of engine maintenance you have done in 7 years of no problems. Carb rebuilds? Fuel water separator replacement? Fuel filters? Cap rotor sensor plugs replacements? Is the motor due for a tune up?

oil change at the start of every season except this one because I hadn't been able to yet.. did plugs cap and rotor 4 or 5 years ago rebuilt the carb around the same time. may be due again. I have not checked the water separator. I will have a look at that tomorrow morning when i get home from work

 

[alldodge]

revs stayed low. they came up a bit but not screaming full throttle. like it was trying to go but couldn't. got moving and big wake but wouldn't plane

Nola headed in right direction
With motor off does the carb open all the way when the throttle goes forward

 

[MikeyArriva]

Probably should post serial number of engine.

Have you inspected contents of water separator?

What kind of engine maintenance you have done in 7 years of no problems. Carb rebuilds? Fuel water separator replacement? Fuel filters? Cap rotor sensor plugs replacements? Is the motor due for a tune up?

it only gets about 15 hours a summer give or take a few. lap around the lake and then drift. I am most likely due for all to be done again. Just seemed like a very drastic problem to just come out of nowhere so thought i would just throw it out here and see what opinions people have

 

[MikeyArriva]

Nola headed in right direction
With motor off does the carb open all the way when the throttle goes forward

i will go check

 

[MikeyArriva]

Nola headed in right direction
With motor off does the carb open all the way when the throttle goes forward

no. not opening at all

 

[nola mike]

no. not opening at all

And not sure how adept with a carb you are, but you're looking at the throttle blades and not the choke, right?

 

[alldodge]

no. not opening at all

We have a winner

 

[MikeyArriva]

And not sure how adept with a carb you are, but you're looking at the throttle blades and not the choke, right?

so its 4 barrel. two on the top not moving but think they need vac? the two under the choke flap are moving but can't tell if fully closed in open they are hard to see

 

[nola mike]

We have a winner

Maybe not

so its 4 barrel. two on the top not moving but think they need vac? the two under the choke flap are moving but can't tell if fully closed in open they are hard to see

Not sure which carb you have. Secondaries won't open unless there's air flow. Primaries may have a lock out that prevent them from opening all the way if the choke is closed. So manually open the choke (or let it open with the ignition on) and then open the throttle.

 

[MikeyArriva]

And not sure how adept with a carb you are, but you're looking at the throttle blades and not the choke, right?

and not very adept at all lol

 

[alldodge]

Bummer

 

[MikeyArriva]

Maybe not

Not sure which carb you have. Secondaries won't open unless there's air flow. Primaries may have a lock out that prevent them from opening all the way if the choke is closed. So manually open the choke (or let it open with the ignition on) and then open the throttle.

I put the throttle down and the cable itself didn't move. I had to manually pull it forward after putting throttle down. hmmmmm

 

[alldodge]

I put the throttle down and the cable itself didn't move. I had to manually pull it forward after putting throttle down. hmmmmm

No I'm not going to say it again, but
Throttle moves and cable doesn't move at the motor. If this is the case then need to reconnect the cable at the motor