We had a customer stop by our shop and asked if we could come listen to a strange noise his
recently purchased boat was making. The boss went down to the boat (which was tied up at the
dock) and came back saying it had a knock to it. Today I got out the stethoscope and
verified it had a connecting rod knocking in it.


This boat started up and ran fine in the driveway, but the seller refused to go for a "sea trial". (see below)

The boating season is around the corner and some of you may be thinking about buying a used
boat. Here's KB's "used boat checklist" to help you make an informed purchase.

First off, perform these checks when initially looking at the boat.
  1 ––  Visual inspection of engine. How does it look? Oily,rusty,corroded,wiring rotted?
  2 ––  Compression check  100 psi minimum for 2 strokes, 4 strokes will vary but should be
150ish. All cylinders should be within 10%. (although Merc now says 15%)
  3 ––  Spark check using proper spark checker. (This test mostly for outboard ignitions)
  4 ––  Gear lube inspection. Remove the drain plug just enough to allow a bit to dribble
out. Water means there's water in it YIKES! Rusty water is a double YIKES! Milky oil is
contaminated with water (leaks) Black oil means it's overdue for a change. New oil will be
transparent, just tinted different colors for different brands. Small amounts of metal
shavings are to be expected, chunks are not.
  5 ––  Run on hose. Start it up and let it warm up for a few minutes. Make sure the
propeller isn't going to contact anything, and shift it in and out of forward and reverse.
Allow some time between shifting it between gears to allow the prop to stop rotating.
  6 ––  Inspect the transom for cracks or rotting. Especially near the bottom of the stern
bracket (outboards) or gimbal housing (sterndrives). Inspect the deck (floor) and the
stringers (big ribs/beams that run the length of the boat) for rot and or softness.
  7 ––  Batteries  How old are they? Are the terminals corroded? Does it look
"pregnant"(swollen). Batteries are pricey these days and old batteries are a good tool for
lowering the price.
  8 ––  Service  When was the boat serviced last? In most cases it will run about $500 per engine (sterndrive) and a little less for an outboard. If the boat hasn't been serviced for the season, you should deduct the service price from the selling price..another tool.
  9 ––-  Bellows and transom rubber (sterndrives) These are the rubber "boots" or bellows that connect the drive with the boat basically.  These should be changed about every 4 or 5 years. Sooner if the boat is kept in the water. This repair runs between $500 and $1000 per engine/drive...another bargaining tool.

If all this checks out, then it's time for a "sea trial". One strong note of caution
here..If the seller won't take it for an on the water test...RUN AWAY! Don't let the seller
BS you and say "I don't give boat rides" or "I don't have time".. RUN AWAY! (see above)

One tactic is to go through the checks I describe above in the driveway. Negotiate a price
with the seller. Then tell him the sale is contingent on the sea trial. This forces the
sellers hand. If the seller agrees to the sea trial and the boat performs as it should on
the water, you probably have a sound boat.

During the sea trial, take note of RPM's at wide open throttle, oil pressure and temperature. Listen for any "rumbling" sounds from the transom., especially when the steering is hard over to the right or left. Note steering effort too. Stiff steering indicates a bad cable or helm, corroded/bound pivot or tilt tube (outboards) Sterndrives with power steering can be stiff from bad cable, pump or steering ram, rusted or corroded steering pin in the gimbal housing. Check shifting again. Does it go in and out of gear easily? Does it stall when shifted into gear? How does it idle in gear? Check for hesitation upon acceleration and stalling when coming down off of plane. Finally, check the bilge for water.

Need I say more?

If you aren't mechanically savvy, take the boat to a shop and have it checked out. The shop
you choose should be on the water or have a dyno to do the sea trial. The dyno will only
confirm engine/drive performance. It won't tell you if the boat leaks! Expect to pay the
shop for an hours worth of labor per engine. A wise investment for such an expensive toy.

I surley can't say you won't have a problem with the boat after performing these checks, but
they will eliminate 99.9% of all the problems we see with newly purchased used boats.
Shoot me an IM if you need info on specific models and or problems. Happy boating!
KB  

Thanks KB.

good info   Thanks!

SUBscribed, as my dad is looking to buy a used boat in a few months.

Let me know if you have any questions about a specific make or model.

Thanks and will do.

The only information he's given me is this:
Saltwater
Fun
Capable of fishing
Cheap
No sails

Beyond that, I guess I'll more information as the Spring and Summer go on.

KB, I am going to look at a 1989 Ranger 363 with a Mariner 150 on it. The oil injection has been removed and the owner has been adding oil to the main tank. I am going to take a compression gauge with me, anything else i need to look for on this particular engine?

Edit: What about todays ethanol fuel in the older engines? What octane would you recommend?

Thanks for any info

Compression, check for water or milky oil in the lower unit, spark with proper tester, wiring condition as mentioned in the original post. Mixing your own oil is fine. Many of the oil injected motors have had the oil pump removed. They sometimes shred the plastic drive gear on the crank for the oil pump. This is why some are removed. Alcohol in the fuel will make the rubber hose and other rubber components in the fuel system brittle.  Mid grade or premium fuel will help prevent detonation.
Take note of the RPM's at wide open throttle. It should be within the motors recommended RPM range...4600-4800 IIRC for that motor. It will say what the RPM range is on the transom bracket.
Take it to the lake and run it on the water!! Running on the hose is only a preliminary check.
Find out when it was serviced last. If it needs service for this year, you can use that as a bargaining chip.

   KB7DX has always let me bother him and gave me an opinion! It's what makes arfcom great!   His service here is greatly needed and appreciated, and he knows his stuff!     Sorry KB for aggravating you so much.   Moneys hard to come by lately and i'm gonna use EVERY resource available before i spend mine.  Thanks again KB

Thanks smalljaw. One of the worst aspects of my job is informing the customer that his newly purchased boat needs thousands in repairs. This discourages new boaters and alot of the time they just sell the boat at a big loss and forget about boating forever.

On a lighter note, another bad aspect of my job involves pulling all kinds of...ummm....stuff..out of Vacu-Flush toilets.

Anyways, if anyone needs advice on a boat or engine, IM me. I have been working on boats professionally for 8 years. I was an auto mechanic before I attended MMI in Orlando. If there is something I don't know, I can ask the older techs at work who have been in the industry for 30 plus years.
KB

Story time!!!

OK, we had a marina member who was quite the ladies man. He would have several bikini clad chicks on his boat every weekend. Every Monday morning, we would get a call from him saying his "head"(toilet) was broken again and wanted us to fix it under warranty as we had fixed it several times before. This time, we fished the used "feminine hygene product" out of the system and saved it in a baggie for him. When he showed up the next Saturday, we presented him with the prize. We told him we didn't warranty things like this. He said.."oh well, you pay for it one way or the other.."

lulz...glad i don't have that job!

So the boat my parents are looking at now, is a 1989 Pro Line 17 foot center console with a 150hp Johnson motor. The motor has 30 hours on it and still runs. The owner still takes it out fishing.

ETA: Forgot to add, The owner is a friend of my parents, and is going to take my parents and I for a ride whenever we want.

Not buying a boat anytime soon but great info.

Tag.

How can someone check for a spun hub without putting the boat on water?  

This bit me on the ass when I bought my boat.  Didn't find out until I got the boat in the water and no ammount of throttle got me past the ducks swimming at the ramp.

There are a couple of ways to check for a spun hub out of the water. The first way, and safest I might add, is to remove the prop and look for rubber chunks where the splined hub is molded into the prop. This obviously only works for a molded rubber hub. The newer Mercury/Quicksilver props have a replacable plastic hub. In this case, you remove the splined hub from the plastic insert and look at the insert's condition. It may take some tapping with a mallot to remove the plastic insert, but most of the time it's real obvious when it's spun.
The second way is to place the engine in forward gear and try to rotate the prop backwards by standing on one of the blades. This is the most dangerous way!! Make sure the engine cannot start! Do not do this on a warm engine! Remove plug wires (outboard) or coil wire (inboard/sterndrive) .
This method is not 100% accurate. Sometimes a hub will pass this test, but slip when loaded in the water.

Bump. It's spring again! Any perspective boat buyers have any questions?

this ^

Good info. Thanks!

KB, I'm only getting 43MPH at 5300RPM out of my OMC 99' FITCH 115HP on my old heavy (1450 Lbs. dry hull) 83 17' Pro-Line CC. This has been the case since I rigged the engine back in 03'. It has a 17" pitch SS Michigan wheel. Manual says I should get 5500-6000RPM for a good wheel match. A Very reputable local prop shop says they can jig and beat out some pitch to get another 200-300RPM for $125. Boat has a great hole shot now and good cruise at 25MPH at only 3500RPM. I think going to a 15" wheel will send me over 6000RPM WOT. What should I do? Leave it alone or settle for the 200-300RPM gain with the re pitch? Another 5MPH top speed at 5800RPM is my objective and would be perfect.

Generally speaking, decreasing pitch "one step" (17 down to 15 pitch) will gain you 200-300 RPM's. Best thing to do would be to try some different props/pitch. See if the prop shop will lend you a few different props to try out. You will most likely have to leave a $$ deposit (unless you know them well) on the props. Take them out and try them. Propping a boat correctly usually takes going through several prop styles and pitches. You will find that some props perform better than others even with the same pitch. Michigan Wheels aren't known for their "performance" capabilities. Some guys find they need two props. One for a heavily loaded boat and one for a lightly loaded boat. How is the hull on your boat? Does it have any irregularities, hooks, rockers or rough bottom due to marine growth?

Hull is clean. Simple modified Vee. My old OMC 115(carbs) would 45MPH at 5700RPM with same prop. I was told the 115 fitch runs the V-6 gear case with a different gear ratio than the 3 cyl and old V-4. If this is true I might just try a 15".

I don't know if the ratio is the same, but there are a few different ratios out there. Wouldn't hurt to try a 15 pitch.

Good info!

I just sold my 4-wheeler yesterday, so I can buy a boat.

I've been looking at a LOT of different boats lately, now that I have cash in hand, I can get serious about looking.

One that caught my eye was an 1987 "Wahoo Bay Boat", with a 1988 yamaha 70hp.

I'm wanting to go take a look at it this weekend.

Any "known" issues with this boat/ motor ?

While I don't have any specific info on the boat itself, the Yamaha outboards seem to be very reliable. I can't recall ever seeing one with major issues. Granted, we aren't a Yamaha dealer, but see 6 or 8 a year in the shop for minor repairs/maintenance. If the hull looks good and not rotted out, I wouldn't be afraid to buy a used Yamaha outboard...after a "sea trial" of course.

Good advice.

No sea trial no buy.  Period.

First, this is a great thread. - thanks for any help you can give.

OK, the wife unit has talked me into buying another boat.

It's been about 10yrs since I owned a boat (and it was an old Bayliner w/a 2-stroke)
- WOW things have changed.
No more mixing oil and gas....  e-techs, optimax, the 4-strokes are pretty quiet....

We finally found a bay boat we both could agree on.

2009 NauticStar Model 1810 - 18'2" w/90HP 4-stroke Yamaha outboard (also 2009)

I know it has been used in salt water, everybody here pretty much goes to the coast.
Redfish bay is a big lure.
That being said, it is a very clean looking boat, no corrosion, no rust on the boat, motor or trailer.
Hull looks new, no cracks, no scrapes, no oxidation, transom looks fine.

I pretty much followed all your suggested checks, except running the engine.

We are buying from a dealer, he is servicing the boat this week and we have a sea trail set for Friday morning to complete the transaction.
If all goes well, we are bringing it home (after a weekend of fishing)

I downloaded the Yamaha owners manual and have read through the operating instructions.
I will check what RPM's we get at WOT and will have a GPS with us to check the MPH. (According the the spec sheet for this boat, it should do ~40MPH@6000RPM).
There is a water pressure gauge for the motor and Yamaha states anything over 11psi is OK.

I also downloaded an i-Touch app from Yamaha, entered the S/N for the outboard and it confirmed that this motor was sold with this boat.
(It gives the boat hull number and where & when it was purchased)
Gotta love technology.

Any other advice or things to look out for?

Looks like you have it covered. The water pressure at idle may be lower than 11 PSI, don't sweat it as long as it makes 11+ PSI when running WOT and doesn't overheat during an extended idle period. Is the engine an EFI unit or carbureted?

It is a F90TXR - EFI
We have been seriously looking at boats for about 3 months now,
I have not found any major complaints about this engine.

Ok, I was just curious. The Yamaha's have a good reputation, so good that Mercury uses Yamaha powerheads on their 4-stroke outboards...they just paint them black.

Not anymore. Merc used to buy their powerheads from Yamaha but since Brunswick tried to sue Yamaha for flooding the market with motors Yamaha has cut them off.


Most Merc 4-strokes are now built in China and some in Japan. Their smaller HP motors are made by Tohatsu.


Yamaha motors are very reliable. We sell 150-175 of them a year and our warranty is just about zero.

Have your local Yamaha dealer plug it into their laptop. You can see how many hours are really on the engine and at what the RPM the motor was used the most at.

Including any codes that may have occured.

Thanks for the correction akethan. I figured it was just a matter of time before the Chinese infiltrated the marine industry. At least they are copying a good engine. I knew Tohatsu made the smaller 4-strokes but didn't realize the Chinese had taken over the larger powerhead production. When I was at Merc-school 2 years ago they referred to the 4-strokes as their M I C product (Made In China) but I was under the assumption that Yamaha had moved production to China. Merc likes to keep us in the dark about alot of things..

Good idea, thanks.
I believe the engine has 126hrs. - but I am going to check that.
Not sure if that is considered a lot of hours or not. (engine was originally purchased 08/20/2008)

126 hours isn't alot. Like akethan said, the dealer can download the true hours as well as a breakdown of what RPM ranges the motor was run at. The data will look something like this:
RPM         HRS
0-1000      20.6
1000-2000 18.9
2000-3000 54.3
3000-4000 10.2
4000-5000 13.3

etc...

Thanks for all the info.
the 126hr figure came from the salesman,
He said when they take a boat in they hook them up to get the hrs and check for error codes, etc.

We are headed to the dealer tomorrow and I will see if I can get them to hook it up or if they made me a printout.
I was planning to install an hour meter.

I see that it is possible to buy the Yamaha cables and software (e-Bay)
Think this is worth doing?

My Dream Now to win the lotto...

Yamaha released a new system last year so I'm sure there are a few dealers selling their old equipment.

Thanks for the help guys.
KB thanks for the RPM/Time info.
I got the printout, turns out the motor only has 84hrs on it.

Picked up the boat today and headed out fishing in the morning.

Congrats on the new boat! Post up some pics in the "Post pics of your boat" thread.

and tag

I just bought a 2003 Duracraft 160 basic bay center console with 2 stroke merc 90HP.  

I had the seller so a trial and boat ran great. I didn;t do a compression check, so I hope it is ok.

I'm been out of the boating world for 35 years, and have a question about the muffs to run the engine.  I see there are square ones and round ones.  Which do I need, and they just fit over the water intake, right?

When I was a kid, I used to start a 40 evinrude in a garbage can.

Thanks

Don't matter, I have the square one's, over the intake on the lower unit is correct.

Either muff will work. That sounds weird huh?
ETA–– don't rev the motor over 1800-2000 rpm's on the muffs. The muffs won't supply enough cooling water at high rpm's and 2-stroke engines don't like to be revved up without a load on them.

Can someone recommend a 19-22' boat that does crossover duty- primarily fishing in Tampa bay area, secondary use will be
cruising out to islands with the wife and dogs, possibly 4 people.  I can spend up to 20k.

Thoughts on a 99' 115 ficht ram?

I have read the issues that they could have, and I know that the resale value is shit on it, but my thoughts are if it is running 14 years later it isn't one of the shit motors.  I have also read that the v4 engines were relatively reliable.  I will be taking it for a ride, and am going to bring it by a dealer to get hours, etc.

Ok as long as I understand it is a 10+ year old 2 stroke?  Or should I only pay what the hull is worth?

Thanks!

I have an 2001 200. I know its apples and oranges but both are grouped in the "FICHT" sucks group. Have the dealer look up the SN and check and see what work has been done to it. As long as the "updates" were done to it you should be fairly good to go.

Run away!  

Well, I was looking for more info than just that.  Like I wrote, I may just offer what the hull is worth.

Thanks devildog, that is along the lines of what I read, although the 115s don't have the need for the updated pins, etc.