Questions tagged [boat]

Questions about boats, boat engines, and other relevant (mechanical) questions about watercraft

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Does engine oil get old and go bad?

Does engine oil actually go bad from just sitting within an engine that's not getting use? I feel conventional motor oil has been sitting underground for millions of years prior to being extracted and ...
Travis's user avatar
  • 223
11 votes
4 answers
2k views

Starting a 2 stroke jet boat after several years

The parents in law gave me a jet boat, it hasn't been started in 5 years. The boat resided in NH on a trailer on their yard for 5 years, so it has seen freezing temperatures frequently. From what I ...
Calvin's user avatar
  • 489
9 votes
2 answers
927 views

Carb. Rebuild or Adjustment?

Just put a rebuilt 2 stroke and brand new Mikuni SBN carburetor in my jet boat. Got her running no problem the first couple times, now it seems I can't get any gas into the carburetor from the primer ...
Calvin's user avatar
  • 489
9 votes
1 answer
4k views

What is the yellow precipitate in my outboard's carburetor?

I've got a 2008 Tohatsu 9.8 HP four stroke outboard. My low speed jet keeps getting fouled and on several occasions, I've found yellow almost crystalline "growths" for lack of a better word inside ...
delliottg's user avatar
  • 233
7 votes
1 answer
3k views

DIY Alternator Belt Tensioner

I've got a diesel engine in my boat, but the previous owner had somehow snapped the alternator bracket, and fitted it fixed to the boat rather than the engine. Now the alternator doesn't move when the ...
Adam's user avatar
  • 203
6 votes
2 answers
568 views

Is there such a thing as a biodegradable (boat propeller shaft) grease?

I'm using a Volvo Penta Propeller Shaft grease to to lubricate and seal the propeller shaft in my boat. The grease eventually gets "squeezed" out from the various lubricated spots and ends ...
sbrattla's user avatar
  • 183
6 votes
3 answers
5k views

Boat Not Getting Power to the Starter Motor

Just rebuilt most of a 2 stroke jet boat. ( if you need / want any boat details, see: this thread ) First day the boat started fine, no problems, next day I tried again and the CDI fuse had blown ( ...
Calvin's user avatar
  • 489
5 votes
1 answer
267 views

Which engine part is this?

I own a speedboat that is powered by a 5 liter V8 Mercruiser with 200bhp. Yesterday when trying it out for the 1st time this season, 2 things happened: 1 - the boat was always trying to turn left ...
Andre's user avatar
  • 238
5 votes
2 answers
6k views

Where Does My Boats Main Negative Battery Terminal Wire Go?

Just rebuilt most of a 2 stroke jet boat. ( if you need want any boat details, see: this thread ) When I purchased the boat, the thickest negative battery terminal wire was not connected to anything....
Calvin's user avatar
  • 489
4 votes
4 answers
4k views

Why do I connect the positive and the negative to the battery on a boat?

My trolling motor for my boat has a black and a red connection. The red goes to the positive on the 12 volt battery. The black goes to the negative on the 12 volt battery. Could I connect the black ...
USER_8675309's user avatar
4 votes
1 answer
469 views

What RPM to check timing?

I've got a question about my 1985 454 Mercruiser engine. I'm trying to adjust the timing but when reading through the engine manual it sounds like it's giving contradicting information. On page 27 is ...
Dehli's user avatar
  • 143
4 votes
1 answer
1k views

Engine Turns but won't start

It's an old Renault 4-cylinder carburetor engine in a boat. I don't know much about engines so let me know if I'm not including important information. The boat is old but new to me. I drove it for ...
Peter's user avatar
  • 213
4 votes
1 answer
2k views

Re-wiring Harness in Jet Boat w/ Ford 460

I'm replacing the wiring harness on my jet boat. It has a Ford 460 in it. The boat has five gauges on it. A tachometer, oil pressure, amperage, fuel gauge, and water temp. There is also a toggle ...
gh0st's user avatar
  • 538
4 votes
3 answers
2k views

1999 Yamaha 80hp Outboard Electrical Problem (Rectifier Overheating)

I recently purchased a pontoon boat and on day #3 my motor died, I'm hoping to get some help from the community with correctly diagnosing and fixing the problem. The motor - 1999 Yamaha 80hp four ...
Barry's user avatar
  • 51
4 votes
0 answers
982 views

How to wire an ignition switch for boat throttle controller

I have an old Bass Tracker boat. They no longer make the throttle controller for the boat, but I need to replace the ignition switch (which is in the throttle controller). I looked online and this ...
user avatar
3 votes
1 answer
233 views

Quick-release for battery terminal loops (D18S/T3)

I have a D18S/T3 battery that I want to use to power the lights of an aluminum boat. I don't want to leave the battery in the boat when I'm not using it. I figure the elements would damage the ...
User1974's user avatar
  • 1,031
3 votes
4 answers
796 views

Replacing a boat's blown CDI fuse

Just rebuilt most of a 2 stroke jet boat. (if you need / want any boat details, see: this thread) Yesterday, she fired right up no problem, today she won't even turn over. After some basic ...
Calvin's user avatar
  • 489
3 votes
2 answers
97 views

Hardware Installation on Fiberglass boat

I had to rebuild the jet pump on a 1992 boston whaler rage. I noticed a putty like substance on the hardware I removed directly from the hull, I assume it is used to waterproof the bolt holes in the ...
Calvin's user avatar
  • 489
3 votes
1 answer
419 views

Mercedes OM636: Can I Resolder Wire to Coolant Temperature Sensor?

The wire contact connected to the Coolant Temperature Sensor of my Mercedes OM636 (Boat engine same as Mercedes 170D, 180D) was corroded and got accidentally snapped off. Can I just solder this back ...
Meggy's user avatar
  • 133
3 votes
1 answer
68 views

course of action: water cooling outlet in outboard does not reliably produce jet

There is a tohatsu 9.8hp outboard motor which should produce a jet of water out from the cooling outlet when the engine is running, but sometimes doesn't. When the engine is started, (seemingly) ...
mvm_init_js's user avatar
3 votes
2 answers
350 views

Diagnosing a boat that wont start

Having some problems with my '92 Boston Whaler Rage jet-boat again.... See this post for all relevant boat info: Starting a 2 stroke jet boat after several years Ok, so I did basic troubleshooting, ...
Calvin's user avatar
  • 489
3 votes
2 answers
102 views

Boat part what part is this?

I own a boat with Mercury 90 motor. There is a red switch on the engine used as security to start the boat, very simple. I've lost this key and want to replace it, but have no idea what it is called. ...
Erik's user avatar
  • 39
3 votes
1 answer
2k views

Wiring up boat electronics - 240V and 12V with inverter

I've just bought a boat, but the electrical systems need a bit of an upgrade before going cruising for any length of time. At the moment, All the 12V runs from a single starter battery, and there are ...
Adam's user avatar
  • 203
3 votes
0 answers
174 views

No Start, No Crank Issue

I have a Volvo Penta 4.3gxi-g with a no start, no crank condition. This started with an intermittent no start, no crank condition. It is impossible to get to the starter motor itself due to how the ...
Higgs's user avatar
  • 31
3 votes
0 answers
135 views

Boat Inboard engine Losing Power

After about an hour of running, I find the engine starts to lose its power at say 3500RPM, and what I have to do is lower it to 2000RPM, if I try to increase the RPM back to 3000-3500RPM it starts to ...
Dominic D's user avatar
3 votes
0 answers
210 views

Jet Boat, Cavitation or Misfire?

My jet boat is making a 'putting' noise when trying to accelerate. You can find all details regarding my boat here: My Boat Info The noise seems to happen in the mid-rpm range; 4,000 - 4,800 RPMS, ...
Calvin's user avatar
  • 489
3 votes
0 answers
606 views

Yamaha F40F outboard boat engine continuous alarm when starting

I'm trying to start a very new 2014 Yamaha F40F engine on my dad's boat. The engine was used yesterday by my brother without issues but today it won't start at all, and I get a continuous alarm sound ...
user19806's user avatar
2 votes
2 answers
203 views

Prevent inline "waterproof" fuses from corroding

I recently bought a used aluminum boat that has 12v wiring for lights. The wiring has inline "waterproof" fuses similar to this: https://www.princessauto.com/en/in-line-fuse-holder-with-led-...
User1974's user avatar
  • 1,031
2 votes
1 answer
218 views

Ran 2 cycle without mixed gas :(

So I just purchased my first outboard boat motor. It’s a 9.9hp 1997 Mercury. I should have known better but didn’t realize I needed to run 2 cycle gas. So I ran it for about 15-20 minutes total. ...
Hefner413's user avatar
2 votes
2 answers
683 views

Vacuum never decreases while leaning out carburetor mixture

I have a Rochester Quadrajet 4MV carburetor that has 2 mixture adjustment pins in the front of the carb. As I understand it, you tune these by continually tightening the mixture screws while watching ...
Ryan Griffith's user avatar
2 votes
1 answer
169 views

Paint that works on galvanized steel and exhaust pipe

I have a homemade outboard motor extension handle similar to this: https://www.amazon.ca/gp/product/B07BWXZN2J/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1 The narrow part on the right is ...
User1974's user avatar
  • 1,031
2 votes
2 answers
146 views

Where is model number on Yamaha 9.9 4-stroke outboard motor?

I recently purchased a used boat with a Yamaha 9.9 4-stroke outboard motor. I’ve tried looking for the model number so that I can buy replacement parts (someone told me I should have a replacement ...
User1974's user avatar
  • 1,031
2 votes
1 answer
51 views

Normally-high run switch vs coil-ground out to turn off

I'm restoring a 1958 larson Playboy - it looks like it originally came with an evinrude engine as there was an evinrude starter solenoid box in the back. This was cabled into the main key which has ...
Brydon Gibson's user avatar
2 votes
1 answer
65 views

Did I damaged my engine trying to remove the flywheel nut with resistance on the pto coupler?

I was trying to remove the flywheel nut while providing resistance to the pto coupler, now if I spin the flywheel and provide resistance to the coupler the coupler remains in place while the flywheel (...
Calvin's user avatar
  • 489
2 votes
1 answer
2k views

I have a Mariner 5 HP outboard. I need info please?

My Mariner is a 5 HP model 5M, Code 6E3 S, and Serial # 148968. I'd like to know who made it, what year model it is. Help Please !
Donkeyman's user avatar
2 votes
1 answer
7k views

How can I do a simple coil test to check for spark

I've got a boat engine which will not start. The engine was factory refurbished last year, so I do not expect wear and tear to cause the issue. I do not see sparks on the plugs. So I'm trying to test ...
sbrattla's user avatar
  • 183
2 votes
1 answer
4k views

Ford 460 Does Not Start Only Backfires When Cranking Over

I have a Pioneer Jet Boat with a Berkeley Pump attached to a Ford 460 big block. The 460 has a Holley carbureter, and Basset water-injected headers. The engine was running fine until one day when ...
gh0st's user avatar
  • 538
2 votes
0 answers
43 views

New 2.5 hp outboard motor has reduced power at full throttle

I have a new 2.5 hp 4-stroke Mercury outboard motor on a 12-foot aluminum boat: I've used the motor four times; 15 km per trip. When I first got the motor, it seemed to have a lot more power at full ...
User1974's user avatar
  • 1,031
1 vote
2 answers
165 views

Reduce vibration transferred from outboard motor to aluminum boat

I have a new 2.5 hp Mercury outboard motor on a used 12-foot aluminum boat. When I use the motor, it vibrates the boat and everything in it, which makes a lot of noise. I'm doing what I can to ...
User1974's user avatar
  • 1,031
1 vote
1 answer
403 views

Lighten flywheel to increase top speed?

i have an old gasoline fueled skiff that only makes 3-4 knots. I find this to be strange since the engine is rated at 10-12 horsepower. It isn't that heavy and i figure it should be able to do more. ...
user9534017's user avatar
1 vote
1 answer
120 views

Yamaha 200 HP outboard Ox66 tilt/trim unit frozen screws

I have a Yamaha 200 HP Ox66 attached to a 1986 Mako 20. My tilt/trim unit has been sitting in saltwater in South Florida for some 4 years. I did a piston rebuilt with new gaskets, seals etc some 2 ...
Joseworks's user avatar
  • 129
1 vote
0 answers
93 views

Tools and supplies for roadside trailer bearing repair

I've heard bearings are a common failure mode of trailers. What tools and supplies should I carry in my vehicle for doing an emergency bearing repair? I have a bearing kit: SKF 24 Trailer Seal & ...
User1974's user avatar
  • 1,031
1 vote
0 answers
114 views

1997 Sea Rayder F16 will not crank

looking for some help. Last week had my jet boat out for the first time this year. It ran ok - a bit of hesitation but figured after sitting for almost a year this would be normal until i ran it for a ...
Stan Kita's user avatar
1 vote
0 answers
257 views

2004 Yamaha Outboard 50HP vibrating around half throttle (2700-3100 RPM)

I've recently bought a 2004 Yamaha outboard, specifically a F50 TLRC (four stroke 50HP) and it is generally in good condition, takes a couple key turns on startup but always starts, a little rough on ...
clifgray's user avatar
  • 111
1 vote
0 answers
570 views

1997 Mercury 9.9 HP 2-Stroke starting issue

I've been banging my head on a starting issue with the outboard motor mentioned in the subject line (it's a manual pull-start). Problem is that when I pull it over, it doesn't sound/feel like it even ...
stevieb's user avatar
  • 133
1 vote
1 answer
370 views

What is behind the external vent cover on the driver's side of a runabout boat?

I was power washing my runabout boat today and sprayed over this vent. What is behind the vent? Is it OK to get it wet? My boat is a Stingray, but this picture is from a Bayliner.
Caleb's user avatar
  • 111
1 vote
0 answers
53 views

charging boat battery

I have a heavy (65 lb) battery for my boat & live upstairs (no elevator) in a condo. I don;t wanna keep bringing it inside to charge it & the only power plug I have outside is where I park my ...
hap's user avatar
  • 21
0 votes
2 answers
398 views

Attach small winch to truck bed or rear bumper

I have a 2010 1500 Silverado and a small ATV winch. I want to use the winch to pull a lightweight aluminum boat up a slight incline. I want to temporarily/occasionally attach the winch to the truck ...
User1974's user avatar
  • 1,031
0 votes
1 answer
174 views

Battery connection

I screwed up and touched negative cable to positive on battery and it sparked and now when connected correctly no juice anywhere. Should there be a fuse somewhere?
user53031's user avatar
0 votes
1 answer
48 views

Should I change the engine oil on a boat engine after it sat for 5 months?

I have a Reinell Bowrider, with a 190 HP Chevy engine, that hasn't been started in about 5 months. Before starting it, should I change the engine oil? Or will it run okay without changing it?
Sonya's user avatar
  • 1