Inboard Engine Analysis

[mperki03]

This is obviously the ultimate forum for enging knowledge-sharing!<br /><br />Can someone provide me with key points to consider when I go to look at a 1979 Bonanza w/ an inboard engine. I don't know the engine details...I want to ask the appropriate, general questions and know the correct answers. I know all about the outboards I've owned, but what maintenance and operational questions should I ask about an inboard?<br /><br />I apologize for this elementary forum entry, but this seems like the best place to go.<br /><br />Thanks.

 

[GodsBeast]

Re: Inboard Engine Analysis

MPerki03, I am not a Mechanic, and don't pretend to be. It might be more helpful to these guys that are, if you give more information on the Model of Bonanza your talking about, and model, and type of I/O that is in it.<br /><br />So far as the Basics, make sure you can get your arms around the Engine Compartment to do maintance. Make sure you can get to the Engine Oil Dipstick, without hooking up a Saftey Harness and hanging from a Skyhook! Make sure there is enough space to unscrew the Oil fill cap and use a funnel to add Oil. Look and see just how much trouble it is to get to the Oil, and Fuel filters, etc. <br /><br />Check it out real good, ask how much of the Boat has to be taken apart to pull the Engine! Some types and Styles have the Boat built around the Engine, and I have been told they are a Nightmare to Pull that Engine, and very Costly! Also, picture yourself dropping a wrench, or a nut and bolt into the bottom of the Engine Compartment, Can you get your hand down there to get it out? <br /><br />Also, if they have the new style Oil Drain hose kit, already attached to the bottom of the engine, (or any engine) make sure that the Oil drain hose, will fit through the Drain Plug hole to change your Oil. <br /><br />I let the pro's handle the technical parts of the Maintenance program, but they really need more information to go on, so far as Model numbers, etc. <br /><br />Good Luck, GodsBeast

 

[Northern Eclipse]

Re: Inboard Engine Analysis

Give the motor a good visual inspection and feel all around the valve covers feel around oil pan and front timing chain cover and the the back of the intake, you'll be looking and feeling for oil leaks, look for signs of rust stains at the exhaust manifolds and risers or mineral deposit stains, these could be signs of cooling leaks, at this time do note if motor is warm or cold, you want cold, because you want to start the motor cold. Pay attention to the wiring harness also, does it look neat or is it a rats nest, with corrosion on terminals and such,look at the belts also are they cracked and worn, does the boat have power steering? if so look at power steering pump and hoses for leaks, if boat has power tilt/trim, make sure it works also look at pump and hoses for leaks. I almost forgot to mention one very important thing,, use your nose sniff around carb, fuel pump and all fuel connections, you don't want to detect a strong fuel smell in these areas, a slight whiff of fuel at carb would be O.K, but nothing more, while your at it checking for fuel leaks, this would be a good time to check if bilge pump and blower are in good working order. I think you should be able to judge easily enough at this point if boat is worth going any further to persue or not,If motor looks nasty then I would suspect that maintenace is poor, If looks clean and neat, then you need to look carefully at the rest of the boat, seats carpet, gelcoat, is floor solid or spongy etc. there is more to a boat than the motor, with most of the used boats I have looked at over the years the motor has been the least of problems with inboards, most problems I have found are hull/floor/transom/stringer problems, bad outdrives or just plain nasty looking boats, but most have all ran good. sorry for the long post, but in a nutshell you must consider the overall condition determine how much good and how much bad, If in doubt get a professional survey, it could save big bucks down the road..........good luck .

 

[mperki03]

Re: Inboard Engine Analysis

I appreciate the responses. I will probably make a checklist (in my head; I don't want to look like a jerk) and from you guys have said, make a visual decision. <br /><br />Good advice about the rest of the boat. It is easy to be sold on engine function and ignore other vital parts of the boat. I am finding myself caught up in the nostalgia of the inboard boat already. <br /><br />What about the drive shaft? Is there an easy way to determine how well it functions or if there are any problems where it enters into the boat?<br /><br />Thanks.

 

[scamper]

Re: Inboard Engine Analysis

If you’re talking about a straight inboard than the shaft is attached to the transmission via a coupler. Check that the coupler is in good shape, no rust and such. The shaft then goes through a shaft log or stuffing box on the bottom of the boat. The stuffing box is usually made from bronze. You should notice a slight drip coming from here. This is ok as that drip will cool the shaft log as the shaft turns. If it did not drip you will burn the stuffing out and have a much larger leak. Check the through bolts that hold the shaft log on, probably 6 or 8. Make sure there is no corrosion on these bolts. Tie the stern to something solid and place the engine in gear. Check that the shaft is turning true. If it wobbles could mean bent shaft, or coupler not aligned with the engine. Either of these things can cause your shaft log to go out. If the boat has been running in salt water you should have it pulled and check for sinks on the shaft and rudder. Also corrosion on the shaft, wheel and rudder. I don’t know how large this boat is or what you are paying for it but it would probably be a wise investment to get it surveyed. You got some very good advise from the other posts. Go ahead and make a list. If you are afraid of hurting your pride,there is a good possibility you will pay for that later.

 

[Dunaruna]

Re: Inboard Engine Analysis

I agree with paying someone to give it a look over, a little spent now saves a lot later. As with a car, look for sludgy oil, rusty cooling system, old hoses etc. All signs of little or no maintenance. Good luck.