Engine bogs out under load at 2400 rpm

[jackmorgan]

Hi, Just put my 'new to me' 2007 four winns vista 258 in the water today. Tested engine and transmission before putting it in the water. Everything is fine with no load - revs to 5500 and idles perfectly. When out on the water it seemed fine up to 2400 rpm (approximately) but wouldn't go above that with WOT. There was some vibration above idle, but nothing too bad. I just changed the ujoint and exhaust bellows, but the alignment tool was backordered from volvo so couldn't do it. What could be causing this? Limp mode? Could a vibration from misalignment trigger limp mode? Just a little more info - the boat was sitting for 18 months. I drained and refilled the fuel, changed the fuel filter, oil, gear oil and everything else in the service manual. Only 70 hours on the boat. Volvo penta 5.7 Gi-G engine with DPS-A sterndrive. Any help would be appreciated. Thank you.

Jack

 

[Fun Times]

but the alignment tool was backordered from volvo so couldn't do it.

What Volvo part number/s where you trying to order?

Alignment tool # 3851083 ,,, http://www.ebay.com/itm/Engine-Driv...m3f3f46ca69:m:mgf6EcqwbmGO00A-LwDZyYw&vxp=mtr

Handle # 3850609 ,,,, http://www.ebay.com/sch/i.html?_fro....l1313.TR0.TRC0.H0.TRS0&_nkw=3850609&_sacat=0

What could be causing this? Limp mode? Could a vibration from misalignment trigger limp mode? Just a little more info - the boat was sitting for 18 months. I drained and refilled the fuel, changed the fuel filter, oil, gear oil and everything else in the service manual. Only 70 hours on the boat. Volvo penta 5.7 Gi-G engine with DPS-A sterndrive. Any help would be appreciated.

Usually if it was limp mode you should be hearing a warning horn as well.

Did the drive slide in and out easily?

Since it appears you may have just done a full service, did you install new spark plugs and/or distributor cap and rotor?? If so, you'll want to double check the plug wires (firing order) between the distributor cap and spark plugs. If the plug wires are out of sequence then that could contribute to a vibration normally only found under load. In neutral the engine typically will rev up and show no sings of running issues even when there's a known problem under load.

Did you by chance try turning the distributor assembly at all trying to time the ignition timing?

Be sure the propellers aren't/didn't get bent somehow.

 

[Shaper79]

Maybe the injectors/lines are a little gumed up from sitting to long. Maybe some seafoam or a good dose of stabil marine injector cleaner and run her for a while.

 

[jackmorgan]

What Volvo part number/s where you trying to order?

Alignment tool # 3851083 ,,, http://www.ebay.com/itm/Engine-Driv...m3f3f46ca69:m:mgf6EcqwbmGO00A-LwDZyYw&vxp=mtr

Handle # 3850609 ,,,, http://www.ebay.com/sch/i.html?_fro....l1313.TR0.TRC0.H0.TRS0&_nkw=3850609&_sacat=0

Usually if it was limp mode you should be hearing a warning horn as well.

Did the drive slide in and out easily?

Since it appears you may have just done a full service, did you install new spark plugs and/or distributor cap and rotor?? If so, you'll want to double check the plug wires (firing order) between the distributor cap and spark plugs. If the plug wires are out of sequence then that could contribute to a vibration normally only found under load. In neutral the engine typically will rev up and show no sings of running issues even when there's a known problem under load.

Did you by chance try turning the distributor assembly at all trying to time the ignition timing?

Be sure the propellers aren't/didn't get bent somehow.

for the parts i just asked a local dealer - needed them within a couple of days so ebay was out.

Didn't hear a warning horn. Beeps 3 times when in turn the ignition to 'on' - think that's normal.

drive slid in ok.

mine has 'direct ignition' i think it's called - no distributor. all plugs look fine.

plug order is ok.

props look fine.

did a compression test and high was 200, low 190 - pretty solid i think.

did a vacuum test and vacuum seemed very low - 4 in HG at idle. I did this test at the hose coming off the valve cover - disconnected the hose from the flame arrestor and placed the gauge there. I think this is 'after' the pcv valve - would this influence my readings?

thanks.