Engines Stalling

[Jeepster04]

New member here. Been reading for awhile though, tons of info around here!

We purchased a boat with dual Volvo Penta 5.0's and Volvo DuoProp out drives this past spring. Both engines ran great all summer, started right up and ran fine. Since we were new to this type of boat, I think we were a little ignorant about maintenance and took the previous owners word saying it just had a 'tune-up' for granted. We have no idea what they includes and he didnt either.

The problem were having is when idling around pulling out of the dock, shifting into or out of forward or Reverse gears out on the lake, and of course idling back into the dock, etc. The engines will stall when shifting into gear, after youve already shifted, its really kinda random but boy does it scare the crap out of you when youre backing a 78ft boat out of dock towards other boats and BOTH engines die at the exact same time. They seem to run fine when you throttle them up. I did notice that the port engine was running around 400rpms lower than the starboard engine at WOT. The Starboard was running around 4,400 while the port was running around 4,000rpms. Im not sure if both engines are dying at the same time or if one dies and we dont notice it then the other dies. Im sure some of you have noticed sometimes when a engine dies the tach will stick at that rpms till you start it back up.

The season kinda ran out on us before we really started to study on these engines and what needed to be done. We were able to change out the spark plugs which were in decent shape besides being a little fouled(wish I had pics). We changed out the Water/Fuel separator on the starboard engine and it was full or junk/rust. The starboard engine had a fuel pump go bad which is why I change the filter, weve not changed the filter on the port engine yet but we will come spring. We were thinking of getting the carbs cleaned and adjusted in the spring but were not sure if thats the problem($$).

So far weve got new distributor caps, rotary buttons, already put new plugs in it, and were going to replace the impellers just b/c. Also going to change the oil since it needs to be done.

Any advice is welcomed!

Number from port engine:

4100113751

 

[Jeepster04]

Re: Engines Stalling

Could you elaborate on what you mean by that?

A hose comes from a 100 gallon tank, through the filter, to the pump, then to the carb. I had most of that off when I replaced the fuel pump on the starboard engine and all seemed fine. Engines run great under load beside the port being lower in rpms. If the starboard engine was having problems getting fuel I would think it would miss some under load.

Port engine could have fuel problems since it runs at a lower rpms at WOT..

 

[projecthog]

Re: Engines Stalling

Yep I agree,....Purge the tank(s) and at least check the rest of the fuel system to the pumps, check the timing and see if it will run normal.
It "sounds" like fuel could be the problem.
Seeing you have done some of it , I would say do all of it including the tank and up to the carbs to get it shipshape from one end to the other, then you know it's done right and you won't have that to worry about.
The crud that you found had to have come from somewhere.

Are both engines consecutive in serial #'s? Are the hours on both the same or close? if not you could have two mismatched engines, and performance may suffer even though it did fine for the season. Temps may indicate a problem with matching if they differ more then 10 degrees WOT.
RPM is also one way to give a possible indication of that.
One low and one high at WOT.

Stalling can be just a fuel problem, or also how it is set up to interrupt ignition when shifting if it is equipped like that or carb setups or timing.
I am by no means an expert, but there's certain things that need to be adressed to ensure proper matching of the engines.

PH.

 

[chiefalen]

Re: Engines Stalling

To me i seems that the lower cables might need adjusting.

Thats why they are both cutting out.

To the rpm issue are you sure they are correct the readings you are getting.

External tach hooked up to both engines will give you the correct numbers.

They make one that just clamps to a spark plug wire. I'll look to see if i can find the link someone just posted.

The fuel pickup in the tank could also be clogged and the anti-siphon valve could be clogged. The gas have a y in the hose could be clogged there.

 

[chiefalen]

Re: Engines Stalling

Woa forgot my manners, welcome aboard heres the link to the tach.

http://www.esitest.com/cart/325.html

You posted this is a 78 foot boat ?

 

[Don S]

Re: Engines Stalling

To me i seems that the lower cables might need adjusting.
Thats why they are both cutting out

Chief....... You really should post on things you actually know something about. Since Volvo's don't have "Lower cables" how would you suggest he adjust them.


Jeepster04
It really sounds like you have a fuel problem for sure, but you need to get that fixed, if there is rust and water in the tank, here is a way to get it out.
http://forums.iboats.com/showthread.php?t=212830

Then put on new fuel filters. Those 500A engines you have should have a filter on the engine (Starboard side). If there was enough of that rusty water in the filters, it may also be plugging up the idle circuits in the carbs. which is why the engines run ok at higher rpm. So they need to be opened up inspected and rebuilt.
Does each engine have it's own fuel pickup from the tank? If not, they should.
After you get the fuel system straightened out, and the tunups done (You also need to check timing including advance timing) you will need to readjust the idle mixture and speed on both engines. THEN, see how it works.
How about those ujoint bellows on this new to you boat. On that type of Drive, the bellows should be replace every other year. Mostly because the damage of water getting into them could require an engine pull to get things fixed.

 

[Bondo]

Re: Engines Stalling

We changed out the Water/Fuel separator on the starboard engine and it was full or junk/rust.

Ayuh,....

I was headed for the fact that if the Filters are Full of Crap,...

I'm Bettin' the Carb's Idle Circuits are Also Full of Crap....
But,..
Don's got that pretty well Covered...

On that type of Drive, the bellows should be replace every other year.

I hope the Bellows on those are No harder to Replace, than the Impeller in my Merc..

 

[Jeepster04]

Re: Engines Stalling

Thanks for all the responses.

We had planned on pumping some gas off the bottom of the tanks come spring after finding that in the fuel filter. The fuel gauges are not working either so we'll do that while we have the floats out of the tanks(To check them out). It has two 100 gallon tanks but they are around 3/8 of the way full right now. We'll probably pump out a few gallons off of the bottom of each tank. Im not sure if the rust in the filters were from the tanks or from the filter itself. Its un-telling how long its been since the filter had been changed last so they may of just been really old. And yes, Don, the filters are on the starboard side of the engines.

here is a pic of the fuel lines coming out of the tanks:

The lines for the engines come out of both tanks, go into one line then branch off to each engine. The Generator has a line from each tank then it goes into one line where it goes off to the generator. Thats how it was put in from the factory.

Don, I have no idea the last time the bellows were replaced. I also have no idea how to go about replacing those. Does the boat need to be pulled out of the lake? It cost a couple thousand to get this boat pulled out of the water so Im not sure if that will be getting done anytime soon. Were going to try and pull the dipstick out of the tops of the drives to check the oil in those when the water warms up this summer. Would love to change the oil in them...

Guess the carbs will be looking for a cleaning once we get the fuel system cleaned up. We probably will not be cleaning the carbs ourself..

Ohh, Don, I sent you a PM the other day, did you get it?

Thanks for the welcome Chief.

I cannot remember the exact hours off of the engines. One is in the 300 range and the other is in the 200 range(low hours). Its been on a decent sized lake(Nothing like Lake Cumberland, Dale Hollow, etc) since it was new in 1990 and the mechanic that will be cleaning the carbs has been with the boat since new. Engines have been there since new. And yes, its 78' long.

Here are the numbers for both engines:

4100114636
4100113751

I think I covered all the questions.

Ohh, what exactly is the type of out drives on this boat? I know they are DP's but I see people saying 290 DP, etc. Just curious..

 

[Don S]

Re: Engines Stalling

Don, I have no idea the last time the bellows were replaced. I also have no idea how to go about replacing those. Does the boat need to be pulled out of the lake?

You mean this boat sits in the water year round, never haveing the bellows changed, or the gear lube replaced?????
The gear lube should be changed yearly, an yea, you have to pull it out of the water to do that, the bellows are probably lasting longer because you are in fresh water. But they don't last forever (they are thin compared to Merc and the newer Volvo's) and when they go bad you get water in the flywheel cover bearings (why you have to pull the engine to fix) and into the drive. The bellows is what keeps water out of the drive lube.
So yes, you are pushing your luck. I have no idea why any manufacturer would put outdrives on that size of boat. Just because of the maintenance requiered on the drives.

After the boat is out of the water, it's not a big deal to replace the bellows, I can easily do it with in an hour which includes new gear lube. But we can get to that when the time comes.

Here is some other drive and transom shield info.

Also, you may need these manuals along the way
Engine http://www.4shared.com/account/file/70388189/98a8c277/AQ211_to_572.html

Drive http://www.4shared.com/account/file/48536730/fa3b3311/280_to_DP-C_Drive_manual.html

You can download an owners manual and maintenance schedule here.
http://www.volvo.com/volvopenta/glo...ice/publication_search/publication_search.htm

You have a lot of OVERDUE maintenance that needs to be done, and I would bet it will run fine after you get it all done.

 

[Jeepster04]

Re: Engines Stalling

Thanks Don.

Yes, the boat, along with hundreds of other boats at our dock, sit in the water year around. It would take a couple foot ball fields and thousands of dollars to pull these boats out and store them in the winter, its just not something that you cant do. I would love to, however, pull it out and service those out drives but with this dang economy its hard to swing that extra $$ to do that. We would need to hire a low boy to come out, pull it out, find a place to store it while we worked on it, get the low boy back in to put it back in the water... And I would say we would need to replace the fly bridge and such so thats got to be included.

There are boats much bigger than ours that have I/O just like ours. Not sure if they are volvos but from what Ive read they are the best out there.

The link to the volvo website, Ive put our numbers in there and all I can find is a 'brochure' and a 'Product bulletin.' Not sure if Im missing anything there but I would love to have the Owners manual and maintenance schedule if you could tell me what Im doing wrong.

Thanks for those other links!

Edit:

Ohh wow! Those are workshop manuals! Wish I would of found this forum sooner, just ordered one of those a few days ago!

 

[Don S]

Re: Engines Stalling

The newer ones have the schedules, the owners manuals has the schedule in it, have a look.

 

[Jeepster04]

Re: Engines Stalling

hmm, I must be missing something. Once I go to the Product bulletin its more of a tech sheet. Not seeing anything that looks like an owners manual.

 

[Don S]

Re: Engines Stalling

Download the 500B manual, it's the same thing. Volvo did that a lot in the 70's to the mid 90's. The owners manual is just basic info, the service manual gives specs.

 

[Jeepster04]

Re: Engines Stalling

Wouldnt I need the number off of a 500B engine?

 

[Don S]

Re: Engines Stalling

No, just type in 500B in the Engine Type box, just below the SN box.

 

[JustJason]

Re: Engines Stalling

I would love to, however, pull it out and service those out drives but with this dang economy its hard to swing that extra $$ to do that.

I think it's funny that you can afford a 78ft boat, the fuel to go in the boat, and slip fees.

The other thing is.... unless this thing is made of balsa.... i can't imagine it moving very well with twin 5.0L's.

On to a more serious note..... I see the 2 tanks in the pic... but why is there 2 fuel lines comming off each tank?
Another thing is those shutoff valves on the tank.... you don't need those. Alot of them have little kitchen sink type screens and clog up quickly.

 

[Don S]

Re: Engines Stalling

On to a more serious note..... I see the 2 tanks in the pic... but why is there 2 fuel lines comming off each tank?

One for the generator, one for the main engines.

Another thing is those shutoff valves on the tank.... you don't need those. Alot of them have little kitchen sink type screens and clog up quickly.

Those are standard Tempo fuel shutoff valves and do not have screens in them.
He does need those valves. If one tank gets water in it, he can shut that tank off and run off the other tank.

 

[JustJason]

Re: Engines Stalling

I do in fact stand correct then Thanks Don.

 

[Jeepster04]

Re: Engines Stalling

No, just type in 500B in the Engine Type box, just below the SN box.

My bad, wasnt thinking. :redface:

One for the generator, one for the main engines.

Yup.

Ive been hoping that the pickup for the generator is higher than the pickup for the engines. Not that we would ever let that happen but its nice to know the generator wont run the tanks slap empty.

I think it's funny that you can afford a 78ft boat, the fuel to go in the boat, and slip fees.

The other thing is.... unless this thing is made of balsa.... i can't imagine it moving very well with twin 5.0L's.

Just because someone has a boat like that doesnt mean they have money to throw around. Heck, if we had that kinda money we would hire all the work done and I wouldnt be here looking for info. You like flying don? haha, jk..

10-15mph is tops on a boat like this. Its a house boat, not a speed boat. Thing weighs around 70,000lbs.

Thanks for those manuals Don. Looked over them pretty good and we have a general idea how everything works now.

 

[Gazza1]

Re: Engines Stalling

WOW, 2 x 5.0li pushing a 78 footer be it mono, cat or houseboat, I would hate to have the fuel bill. You would need to tow a fuel tanker behind you.
I would think that a couple of diesel's of bigger hp and leg's to suit would be better fuel efficent. At least they wouldn't be working their rings off