Looking at first I/O - what should I look out for?

First boat is an outboard and I've been plagued with problems since day 1. Very hard starting, I'd my biggest complaint. Generally once I get it started, it generally runs fine. Then it was bogging down above 3000 RPM. Rebuilding carbs seem to fix that. Now it's bogging down under load again.

So thinking of moving to I/O. I'm handy with car engines but it seems I don't understand two stokes and they seem o not lik me. What should I have looked over when checking out a boat with I/O. Im sure there are a whole bunch of new variables to make sure I'm not going to have another "moored queen" or "trailer queen"

Thanks

Re: Looking at first I/O - what should I look out for?

Engine hours ,
fresh or salt
Compression test
Does it reach its specified WOT rpm during the water test.
condition and level of the engine oil
condition of the outdrive oil
condition of the exhaust manifolds
condition of the fuel system . . . Tank, pump, carb or injectors.
proper cooling, running at specified temp range.

I'm sure there is other stuff that I have not mentioned . . .

Re: Looking at first I/O - what should I look out for?

When purchasing any new boat, it should be check over by a qualified marine mechanic carefully.

Lower Unit: The grease should be drained looking for any water contamination. Then it should be pressure and vacuum tested to make sure the seals are good. Seal replacement is about $300. To replace a lower unit is $2K+ new, $1.1K used. To rebuild one is very expensive in both parts and labor.

Engine: Compression test is required, and inspection for general condition.

FYI: Marine salvage yards are full of old inboard-outboard hulls with bad engines. Many problems with I/O's are that the engines were allowed to freeze without the blocks drained of water or properly winterized.

I/O's are reliable the first few years. After that, they have problems with weathering bellows on the outdrive. And they're a real pain to replace and get sealed up.

After two inboard outboards with numerous problems, I've since moved to modern 4 stroke outboards. They're very reliable and much easier to deal with.

Re: Looking at first I/O - what should I look out for?

I/O's are not two-strokes. They are marine variations of engines that you would find in a car or truck. Maintenance such as tune-ups, oil changes, etc have the same requirements as a car engine. The outdrives are more complex than outboards so those require a little more attention than an outboard. Your best investment immediately after purchase of whatever it is you end up with is to buy the "Factory Service Manual" for the engine and outdrive on the boat. That would likely be a Mercruiser or Volvo. Avoid any boat with OMC outdrive as OMC went out of business long ago and parts are getting scarce and expensive. If you don't know what to look for, take someone with you that is "very knowledgeable" on I/O's or else have a Marine Surveyor check the boat for you. Always insist on an on-water test and make darned sure you monitor all gauges for proper operation and that they show normal engine operation. All it needs is a tune-up is a signal that something is very wrong. If that's all it needed the owner would have fixed it and the boat would not likely be for sale.

Re: Looking at first I/O - what should I look out for?

avoid any OMC setups, also avoid 470, 170, or other aliases of the 224 CID Mercruiser aluminum block engine.

for a smallish runabout, basically you want a Chevy V6 or V8 in front of an Alpha One drive, or VP if there is good coverage in your area for parts and service of VP... again with VP, try to stick to Chevy V6 or V8 power for plentiful parts.

Re: Looking at first I/O - what should I look out for?

Bamaman1 said:

When purchasing any new boat, it should be check over by a qualified marine mechanic carefully.

Lower Unit: The grease should be drained looking for any water contamination. Then it should be pressure and vacuum tested to make sure the seals are good. Seal replacement is about $300. To replace a lower unit is $2K+ new, $1.1K used. To rebuild one is very expensive in both parts and labor.

Engine: Compression test is required, and inspection for general condition.

FYI: Marine salvage yards are full of old inboard-outboard hulls with bad engines. Many problems with I/O's are that the engines were allowed to freeze without the blocks drained of water or properly winterized.

I/O's are reliable the first few years. After that, they have problems with weathering bellows on the outdrive. And they're a real pain to replace and get sealed up.

After two inboard outboards with numerous problems, I've since moved to modern 4 stroke outboards. They're very reliable and much easier to deal with.

Click to expand...

The bold part isn't true. If you know what your doing it's easy. If you think you know what your doing then maybe a qualified service person should be showing you.