Sterndrive seems to kick-up both in forward and reverse!

Hi, I have a problem on one of my Volvo Penta 290 SP-A Sterndrives and wondered if anyone can suggest remedies.
Twin engine setup and under no wake speed everything is fine. If I increase to planing speed one of the drives seems to lose grip and the revs increase dramatically. The problem also occurs if Increase revs hard in reverse whist docking. At the beginning of the season I could get over the problem by being gentle on the throttles but now with half a seasons fouling the problem is worse.
The problem originated last season but I thought I cured it by replacing the reverse latch springs as one was broken. It still feels like a reverse latch problem and maybe I need to replace all the pawls and catches, but kicking up in forward seems to defy physics!
The trim readings do not alter so the rams or pump is not the issue.
I have had the prop checked for slip.
Gear shift cables all checked and o/k.
As I am on a mooring checking is not easy without a yard lift so need to be well prepared.
So apart from the reverse latch mechanism, could anything else cause this problem?
Thanks in advance.

............

moresparks said:

Hi, I have a problem on one of my Volvo Penta 290 SP-A Sterndrives and wondered if anyone can suggest remedies.
Twin engine setup and under no wake speed everything is fine. If I increase to planing speed one of the drives seems to lose grip and the revs increase dramatically.
Possibly a spun hub.
Mark the inner and outer hubs by making a line through them.
Go out for a run.
When you come back in, see if the line has shifted.

The problem also occurs if Increase revs hard in reverse whist docking. At the beginning of the season I could get over the problem by being gentle on the throttles but now with half a seasons fouling the problem is worse.
The problem originated last season but I thought I cured it by replacing the reverse latch springs as one was broken. It still feels like a reverse latch problem and maybe I need to replace all the pawls and catches, but kicking up in forward seems to defy physics!
I would agree.

The trim readings do not alter so the rams or pump is not the issue.
I have had the prop checked for slip.
Gear shift cables all checked and o/k.
As I am on a mooring checking is not easy without a yard lift so need to be well prepared.
So apart from the reverse latch mechanism, could anything else cause this problem?

On your drive, the latch system and the cylinders are mounted to the Anchorage Bracket (until we get into the C and later drives).

The 290/SP-A reverse latch system prevents reverse kick-up, and is also being used as a "break-a-way" feature in the event of an impact.

Sorry, I don't have a definitive answer for you.

Click to expand...

Hi Rick, Many thanks for your response it is much appreciated. I did send the prop away to a professional prop repair spe******t so it would be disappointing if this is still an issue. I will check though as that would be a fairly easy test.

"spe*******" should be expert.

Hi .. Just a thought..

"The 290/SP-A reverse latch system prevents reverse kick-up, and is also being used as a "break-a-way" feature in the event of an impact."

If the reverse latch system "break-a-way feature" is worn or faulty for instance, can the momentum of the other engine pushing the boat forward cause the other drive to lift?
I know - clutching at straws really!!

Slightly different tack...
If the drive is not lifting and I’m just making an assumption as this is what it feels like... Would this be a symptom of a failing cone clutch?
The drives are nearly 30 years old and as far as I know the cone clutch is original.
If it is the cone clutch I assume this is not a do it yourself repair by the look of the service manual?

moresparks said:

Slightly different tack...
If the drive is not lifting and I’m just making an assumption as this is what it feels like...
1..... Would this be a symptom of a failing cone clutch?
The drives are nearly 30 years old and as far as I know the cone clutch is original.
2..... If it is the cone clutch I assume this is not a do it yourself repair by the look of the service manual?

Click to expand...

1..... The 290 style cone clutch system typically engages without issues. It works in a way in which...... the more pressure against the conical surfaces, the greater engagement force.

If the cone clutch has trouble engaging, it's likely due to debris within the sliding sleeve's oiling groves, incorrect oil, warped gear cup, etc.


2..... for a person with decent mechanical experience, they are fairly user friendly.

moresparks said:

Hi .. Just a thought..

"The 290/SP-A reverse latch system prevents reverse kick-up, and is also being used as a "break-a-way" feature in the event of an impact."

If the reverse latch system "break-a-way feature" is worn or faulty for instance, can the momentum of the other engine pushing the boat forward cause the other drive to lift?
I know - clutching at straws really!!

Click to expand...

Although I have never experienced that, I suppose that if one engine is throttled up above the other, and if the one latch system is not working, it may cause that.... not sure.

I would agree.......... perhaps that would be clutching at straws!



.

When you say drive is "Kicking up".... is this an "eyes on" determination???? BTW... if spring latches aren't correct, forward momentum will cause the drive to kick up with engine in neutral ( or at idle RPM) with forward movement of the boat.

Hi, having thought long and hard, all the symptoms point to a spun prop hub – BUT I have had that professionally checked “supposedly”. Anyway I removed the prop and marked the inner and outer hub and will try again. I will also run just on the offending engine in case the momentum of the other engine is forcing the drive upwards.
As the props are handed I did not want to swap them over, anyway knowing my luck I will drop one in the water! (I really should buy a spare set!)
My only other concern is maybe the cone clutch is worn, so possible symptoms based on experience would be good. I do get the positive typical Volvo “clonk” on the drive engagement both in forward and reverse and they are identical on both engines.
Many thanks for your suggestions.

Just an update:

"IT’S PROP SLIP”

Now I am quite cross as I specifically had the prop sent away over the winter for checking for prop slip.
The prop returned with no report and badly finished paintwork. So much so the paint must have been still wet when they shipped it back as a lot came off on the packaging. After touching up, anti-fouling and installing, all the paint came off in a couple of weeks except where I touched it in. This caused me to completely strip and redo, probably they never primed the aluminium correctly.
It comes to something when you cannot trust the professionals.
This has caused me a lot of wasted time and looking around for other possible faults even bizarre ones as I dismissed the prop as being the culprit “as I had it checked”.
Now my dilemma ... do I send it back for repair, look for another repairer or purchase a new propeller, keeping the old one as a spare.. decisions decisions...

Find a better prop shop.