Volvo penta outdrive

[Wayne R]

I have an older boat (and when I say older boat I do mean older) 1970 Seaflite with Chrysler 273 V8 mounted to a Volvo Penta 270 outdrive. The problem I am having is that I rebuilt the engine about 195 HP but can't get the boat to travel more than approximately 15 miles per hour. I know it is the outdrive but what would it be in the outdrive that would cause this? Any help or insight would be greatly appreciated

 

[Don S]

Re: Volvo penta outdrive

Several things could cause it. Most common, bad prop hub. The drive can cause the problem, usually caused by water in the drive. Have you checked the gear lube and/or changed it lately?
Do you have engine oil in the drive, or 90W gear lube?
Is it going all the way into gear?

 

[Wayne R]

Re: Volvo penta outdrive

I actually have the 90w gear lube in it and there is no water in the outdrive and it seems to go fully into gear

 

[Howard Sterndrive]

Re: Volvo penta outdrive

can't get the boat to travel more than approximately 15 miles per hour.

what rpm is the engine at while you are going 15mph?

revving high?

or in a severe lug..wont accelerate?

 

[Don S]

Re: Volvo penta outdrive

I actually have the 90w gear lube in it and there is no water in the outdrive and it seems to go fully into gear

There is a problem, with a single prop outdrive, you should have engine oil in the drive. The lower unit is designed to move the light oil to circulate in the drive. Probably not your problem, but could be.
Check your prop first.

 

[Wayne R]

Re: Volvo penta outdrive

The RPM are running at about 3300 and yes severe lugg. It feels as though the boat is just waiting for strong surge and wants to take off. Do the U-joints have anything to do with this, I am new to the outdrive repair?

 

[Don S]

Re: Volvo penta outdrive

Sounds more like a gear ratio or over proping situation.
Volvo never used that engine, so the first question that comes to mind is what drive gear ratio and what prop size you have for that engine. Even at that, the drive and prop may not be the problem for your low RPM's at WOT.
Here is a list of possibilities.

List of possible causes of low WOT.

Engine Won't Reach Operating RPM. Check

• Fuel condition. Type and Octane possibly old fuel
• Propeller pitch or diameter, damaged blades
• Restricted fuel pickup tube or anti siphon valve Fuel System Test
• Crankcase oil volume, high oil level can cause aerated oil and lifter collapse
• Marine growth on hull and outdrive
• Wrong gear ratio in outdrive
• Restricted carburetor air intake (clogged flame arrestor)
• Restricted exhaust system (broken exhaust shutters/flappers) in engine transom shield or drive
• Poor cylinder compression Compression Test
• Carburetor defective, or wrong type.
• Fuel pump pressure and vacuum
• Boat overloaded, improperly loaded, or improperly trimmed.
• Engine Overheating
• Engine timing and ignition system operation
• Remote control cables and linkage for proper travel to open throttle plates fully.