Yamaha DT40... n00b here

FujiFrontier

Recruit
Joined
Jan 1, 2006
Messages
2
First off, I know how annoying n00b questions that are easily answered by doing topic searches are, so I did a few.<br /><br />My uncle had a boat (make/model unknown) with a Yamaha DT40 engine (1987, if I read the serial # 04003*717357 correctly), he bought it from an obscure family member back in 1995. He used it once or twice and never used it again. I'm 99,9% sure he did no storage preparations before parking it. It's been sitting on its trailer since at least 1997 parked in my great-grandma's backyard. It's been there so long that the cover has eroded through and blew away sometime ago, it's been exposed to the elements since then. I don't know the maintenance history of it, but from reading and doing a few searches I assume it will need:<br /><br />new impeller<br />oil change<br />spark plugs/tuneup<br />perhaps seals on water pump??<br /><br />I tried pulling gently on the emergency pull cord, the one like a lawnmower has, to see if the engine was seized. It pulled with some resistance. Not as easy as a lawnmower but still "pullable." I have no idea if there was still fuel in the tank(s) when it was put away. The hood/engine cover is really nasty, coated with tree sap and other "black stuff." <br /><br />The engine looks decently clean underneath, some oil sheen on the bottom. I see mentions of "muffs" in order to start/run the engine while the boat is parked, and the "pee hole" where water should come out. I know absolutely nothing about boats or their engines; I'm still trying to grasp the concept of "port" and "starboard." :confused: I would greatly appreciate if you could show me a photo where these are located. I assume I would be able to get a set of these "muffs" at a marine store, so that we can try to start the engine?<br /><br />A maintenance manual is probably a good start, huh. I'm mildly mechanically inclined, so taking the plugs out and giving it a shot of WD40 wouldn't be too hard... but replacing the impeller sounds hard, just by looking at the engine. Also, does it take straight gas or gas with oil mixed in like the weed-wacker engine? <br /><br />Mainly, we just want to get it started and "running," we don't have time or the money to keep up a boating hobby, so we can get rid of it. Thanks for your help in advance...<br /><br />Oh, another thing. I tried spinning the propellor and it turned sort of freely. is it supposed to do this? I've seen mentions of automatic transmissions and the like, but I don't know what this boat has. (Is all dirty with leaves and stuff and don't want to climb up into it :p )
 

jafa

Petty Officer 2nd Class
Joined
Mar 10, 2004
Messages
172
Re: Yamaha DT40... n00b here

Ok first things first , a DT40 is a twin cylinder 2 stroke Suzuki. You have to asses the value of what you have. Does it have electric start or hydraulic tilt, these add value. Was the motor used in salt water of fresh? The blue book will give you an idea of value. I cant remeber where it is but its the same one used for cars.<br /><br />Assuming nothing is "broken" , you could be looking at new fuel tank , if the old one was metal and half full when left its corroded and full of gunge. Fuel hoses and bulb. Water pump kit, carb overhaul kit, spark plugs, quart of quality 2 stroke outboard oil , tank of gas and a manual.<br /><br />Muffs are like headphones which sit over the water intake vents behing the prop. The engine must never be run without having water in the pump , either on a lake or on muffs attached to a hose. The prop souns fine at the moment as its probably in neutral.<br />Whilst you are reviving the motor you'll need to premix 2 stroke oil and gas. The engine might have a inbuilt oil system but we'll ignore it for the moment. Use marine oil, not weedwacker stuff as those engines are air cooled. You could start by putting a few spoonfulls of 2 stroke marine oil into the spark plug holes. Tilt the engine up as much as you can. Any marine outboard dealer will have some, at this stage it doesn't matter which brand. Put a socket spanner on the nut holding the flywheel and start to rotate moving back and fourth untill she spins smoothly (plugs out). Let it rest for a while and repeat.<br /><br />Go to brownspoint.com and price that lot up and see if its worth touching. <br />Your going to have to get in the boat to start it up, so you can give it a clean while your deciding. Clean boats always sell better. :D
 

FujiFrontier

Recruit
Joined
Jan 1, 2006
Messages
2
Re: Yamaha DT40... n00b here

Thank you for your reply. It's not a terribly big boat, probably about 10-15 feet long, a simple fisherman's boat, I guess. When I have time I'll post some pictures. In the meantime I guess I'll have to tell mom what to get :p <br /><br />Oh, the boat was used in fresh water, and has n electric tilt unit attached.
 

jafa

Petty Officer 2nd Class
Joined
Mar 10, 2004
Messages
172
Re: Yamaha DT40... n00b here

The good news is that that motor is easy to set up and get going if its mechanically sound. Budget for $200 ish.
 
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