Volvo 3.0gl sx ....not really sure?

[seventeen2]

Hello All
I have had an ongoing problem with these engines regarding stalling when first leaving the marina.
I think I may have solved the problem by tweaking up the tickover as on the gauge, it was only ticking over in neutral at 500rpm?
I just have a question, that I hope someone with the same setup could verify?
When I put the units into drive, noticibly forward there is a loud "thunk" noise as drive is taken up.
All I need to know is if they all do this?
For the record, it did this when the unit was ticking over at 500rpm?
Also while I am on...one more silly thing, My tachos seem to suffer a voltage spike, i.e they settle for a while at, say, 750rpm then the unit will "pulse" up and then settle back to 750rpm.....is this normal?
Thanks in advance for any help given

Danny

 

[bruceb58]

Re: Volvo 3.0gl sx ....not really sure?

It is normal to feel a thump when you put it into gear. I would verify your tach with a handheld tach because it doesn't sound like your tach is working properly.

 

[BeaufortTJustice]

Re: Volvo 3.0gl sx ....not really sure?

The tach in my boat is relatively smooth (I have Faria gauges)...no jerking or pulsing. I also hear and feel a good solid "thunk" as the prop is engaged on my SX drive. Mine idles at about 1000 rpm without load and about 850 under load. I wonder if my idle speeds are too high, or yours are too low? Either way, it is probably not related to your original post.

 

[seventeen2]

Re: Volvo 3.0gl sx ....not really sure?

Thanks for the replies fellas,
The operators manuel states that the rpm should be between 650 and 750rpm in forward gear.
Mine were idling with no load at 500rpm, but this was according to the dash tachos which i am not trusting!
I have managed to get a tacho to idependantley read what each engine is ticking over at.
The pulsing of the tachos is a strange one and definately seems to be some sort of interference.
Someone has suggested that at the back there is a switch for determination of cylinders?


Cheers

 

[zbnutcase]

Re: Volvo 3.0gl sx ....not really sure?

Yes there should be a cylinder selector switch on the tach; however, that would not cause it to "spike" it would just read wrong RPMs. 'nutcase