Help evaluating a motor for purchase

[jmartinccs]

I'm looking at buying a used boat with a 5.0 liter OMC I/O, Cobra Outdrive. I think it has a cracked manifold 'cause it leaks water from that area. The drain plugs are closed. What other problems should I look for, what kind of effort am I looking at to get this boat in reliable running fashion, future problems? I'm looking at $1500 total for boat/trailer in good condition with the motor repaired as part of the deal.<br />

 

[hondon]

Re: Help evaluating a motor for purchase

First of all ,determine where that mani leak is coming from.If it is indeed from the mani itself, then you could be looking at possible freeze damage.Check the oil for any cloudy or milky or overfull appearance that might lead you to believe this thing has a cracked block.Good luck.Be careful.

 

[fone_man]

Re: Help evaluating a motor for purchase

5.0 Litre / 305 CID GM Engine very reliable engine.<br /><br />The manifold you are talking about is Exhaust, right???<br /><br />When water freezes it expands which causes it to break/crack various aspects of this engine. What I have found on these GM engines is that usually your only problem is the manifold... as they say on TV... "WEAKEST LINK" and they are designed that way to break/crack the least expensive part... which can be quite expensive depending on where you buy it!!! They should have a drain plug on them to drain the manifolds... upon removing I normally run wire/screwdriver in them to remove rust deposits to complete the draining!!!<br /><br />A reminder to persons getting ready to winterize thier engines... as an extra percaution, I always leave my plugs out after draining maniflods/block etc... the reason for this is that I know all water will drain... but if in colder climates most people go the extra set & mix antifreeze/water & reseal cooling system!!!<br /><br />

 

[jmartinccs]

Re: Help evaluating a motor for purchase

Thanks for the input, I'll keep my fingers crossed that it is the manifold or the head gasket!!! If its the block I'm done!

 

[kev_79]

Re: Help evaluating a motor for purchase

If it is the block, you might want to talk him down about 5, 6, 7, maybe even 800. 5.0 blocks are dirt cheap, and if you are handy at all, you could have a good boat with a new block for around 1k to 1200. Stuff you can't get cheap, outdrive, marine carb, risers, or anything strictly marine. Good Luck, let us know how it goes.

 

[jmartinccs]

Re: Help evaluating a motor for purchase

Well, we're at the point now where I've offered him $500 for the boat as is and I'll pick up the tab on the repairs. That is an option but I'm still wondering if it will be worth all of the effort. There's also some work to be done on the floor, (mushy over the gas tank). I'm waiting on the final word from the mechanic. It could be a blown head gasket, cracked head or cracked block. I may just end up waiting to find another boat. Gosh darnit!!

 

[kev_79]

Re: Help evaluating a motor for purchase

I bought a 19 footer with 305 merc, for 600 bucks. I am redoing it myself, and have about 1700 altogether right now. But I have done some major fiberglass reinforcing, and some other things. Plan to gel coat the whole thing, and will proabably have about 2000-2300 in it at the end, but hopefully, it's going to be sweet. If you buy one that needs work, plan on getting into more than you initially think. When you start fixing, you'll see something that is so, so, and say, well, while I'm doing it, might as well do it right. This is the right attitude, but can cost more bucks than you originally counted on. Good Luck, and if you do decide to fix, I have recently become somewhat of a fiberglass expert, well, relitively

 

[jmartinccs]

Re: Help evaluating a motor for purchase

Sounds like you did what I want to do with this one. The hull is in excellent condition as well as the inside lamination. But the side walls are somewhat "flimsy" by comparison to other boats. I feel like it will wobble if I take a good wake with it. That's Bayliner though. The floor also has some mush over the gas tank that I'll have to look at. I'm hoping the motor problems won't be as sever as initially expected. Who knows, if it is bad I might even get the boat for 3-400, then do the repairs. I'm in a holding pattern until I hear from the mechanic.