Overheating Problems with my Suzuki DT65

[Bigfishtinny]

HI All


I Just bought a small cabin cruiser with a Suzuki DT65 1982 outboard , i took it out for a spin and it got so hot the wires lying on to of the head melted and I presume sorted out. I took the head of and found the corrosion and a small leak... The engine still turns over no problem and seems ok . What are the chances that something like the beraings or driveshaft got damaged? I am in the process of getting the head repaired and just waiting for some gaskets to put it all together again.

One more thing , where would I ask for some advice on the forum regards to repairs to fibreglass ?


Thanks in advance

[CDK]

If that really is your location, why don't you ask the wizard?

[Bigfishtinny]

not sure what u mean by that CDK

[tom28571]

Bigfish,

Your leg should have had a big yank. It was a pun. Dorothy may be able to help as we only feel like fun this morning.

[gonzo]

Overheats rarely damage the bottom end, unless you have a melted piston and chunks of metal went down. If the cylinders are not scored, it should be ok. In severe overheats, sometimes you get enough wear that it will use oil after.

[marshmat]

The last time I had a Suzuki overheat, the head gasket blew and one entire cylinder (exotic lining that can't be honed, rings, everything) was destroyed beyond repair. They're great motors when they work, but hi-tech comes back to bite you if it ever breaks.

It's unlikely that anything on the crankcase side of the pistons would be damaged by a cooling problem in the head. The fuel/oil/air mix takes care of most of the demands of the bearings, shafts, etc.

Before firing it up again, it'd probably be a good idea to have the cooling system flushed out and the water pump rebuilt, unless this has been done recently. Even if the water pump had nothing to do with your particular problem, they're notorious for sudden catastrophic failures if neglected for too long. If you need to run the engine on land- even for a second- there needs to be water to this pump, as they self-destruct if run dry.

When you get back out on the water, make sure to keep an eye on the pisser hole (usually on the aft starboard corner of the outboard) to verify proper cooling flow.... and on many engines (check your manual) there should also be a steady stream of spray coming out the exhaust bypass holes once it's warmed up. A significant drop in either flow means "Slow down to idle- RIGHT NOW- and have the cooling system checked ASAP".

Re. Fibreglass repairs: From the forum menu, choose "Search > Advanced Search" and enter some suitable keywords, look in the subforum "Construction > Fibreglass & Composite..." where there is already a lot of good info on how to patch up FRP. If you don't find what you're looking for, a new thread in that forum should do the trick.

[CDK]

not sure what u mean by that CDK

I will explain in detail.
This is your 2nd post on this forum where people try to communicate with each other and provide useful advice as best as we can.
Look at the posts on this thread until now: you have been answered by real humans, living in different locations, all of them being part of the planet Earth.

Except you, because you are from Oz. People from Oz need not ask us anything, because that is where the Wizard of Oz lives, who has the answers to all questions.

[Frosty]

I dont think the head could get that hot it would melt the wires and short them I think you have 2 probs there.

If an engine gets that hot it would stop running and before that make horrible pinking noises.

You have a overheat prob ( no alarms?) and you have shorted wires.

The shorted wires could have been part of the alarm system.

[Bigfishtinny]

Thanks for all your help, I should have the head back in a day or two and once i get all the gaskets will just have to see if it runs or not. The wires that melted were the wires going to the coil i figured they shorted and the engine died becouse of no spark( I hope anyways) I don't think this engine has a alarm it seems to be a model just before they came out with alarm systems (at least i can't see any sensores and it has no lights or gauges) the good news is that i found no water corrotion and only thing i can think of causing this was the damage to the head and head gasket. the impeler is brand new and there was water coming out of the pee hole behind the leg. This model does not have a pee hole on the top of the engine it apperently comes out of the exhaust hole.


P.s Oz is slang for Australia same as Downunder :) no witches but we do have some looney Politicians

[Wynand N]

Do you have the serial number of the engine? If so, I can give you the year model and see if she has a warning system in the control box - usually Suzuki has a buzzer for overheating and oil system (autolube)

[Bigfishtinny]

Hi Wynand I'll get the serial number in the morning , it's a bit late here atm.

[Bigfishtinny]

HI Wynand sorry for the late post , had a hectic week.......

the serial number on the motor is 6501103305 :confused:

[gonzo]

Melted wiring on overheats is common. Sometimes there is no damage at all. However, that means that after it got way past the "too hot" stage, you kept on running the engine for quite a while.

[Wynand N]

Hi Bigfish,

Your Suzuki is actually a 1981 model. Here is the factory serial numbers sequence for your model (age) Suzuki.

1980 Serial: 6501-001001 Model: DT 65EST, DT 65ELT

1981 Serial: 6501-100000 Model: DT 65ESX, DT 65ELX

1982 Serail: 6501-200000 Model: DT 65ESZ, DT 65ELZ

There are three remote controls available on these models and on the exploded parts pics, but no warning buzzers are fitted. However, all 65 hp models after these have warning buzzers fitted in remote control box. Hope this help.

BTW, I run an DT85 with t/t on my fishing boat and it is an excellent engine and very powerful.

[Frosty]

Overheats I have had experience of normally save them selves by alluminium from the hot piston crown melting and depositing on the spark plug stopping the engine.

However, Im sure this was'nt a designed safety system.

You need to determine if the wires were melted due to an ampage overload as I personally doubt that the outside of the head could reach 250 degrees and still be running without noises or loss of power-- the required temp for melting simple automotive wiring is in excess of 250.

The paint must be peeling off and stained badly.

[Bigfishtinny]

As Frosty says the paint on the block is disoloured and peeling , it was like this when i got it , the engine ran well , idled perfect thats why I presumed that all it needed was a new impeller as the old one was totaly wrecked. Goes to show when buying a seconhand engine only way to see if there is something wrong is bye stripping it. in a way i'm glad i opened it up as i almost did a rebuild on the motor.

[Frosty]

As Frosty says the paint on the block is disoloured and peeling , it was like this when i got it , the engine ran well , idled perfect thats why I presumed that all it needed was a new impeller as the old one was totaly wrecked. Goes to show when buying a seconhand engine only way to see if there is something wrong is bye stripping it. in a way i'm glad i opened it up as i almost did a rebuild on the motor.

There are many things to see when looking at an old second hand engine. One obvious clue was missed completely (discolored paint).

Nuts and bolts in wrong paces, wires not clipped as standard, new gaskets ( gaskets you can see, engines are painted after assembly), gasket goo, cracked paint on major bolts showing removal, dirty finger marks under the cowling etc etc.

Its actually quite easy to see if an engine has been tampered with, especially if it was an unprofessional job.

But don't feel too bad, buying second hand outboards is usually a nightmare, unless you personally know the engine and seriously know what you are doing.

[Bigfishtinny]

Thanks for that frosty, I didn't miss the discoloured paint , I asked the seller about it and they said it was normal, and they started it and it ran gr8.... the boat was an absolute bargain it'self and even if i have to spend money on a new motor will still probably be woth it. I am hoping the motor is still ok and will run once put together puerly for the reason i like the simplicity of the old 80's engines , I used to own a 55 Yamaha on a SPortsman Cabin cruiser in South Africa and it gave me many hours of fun even though it was older then me :D. Although I am considering mounting a small 2hp backup motor on my boat just in case :)

[Wynand N]

I used to own a 55 Yamaha on a Sportsman Cabin cruiser in South Africa

Since you have fond memories of the old trusted Sportsman cabin cruiser, here it is again. One of many that passed through my shop to have buoyancy flotation fitted and COF'd.

Ugly little boats in my opinion and a bit short on beam, but well loved by fisherman all over the country:cool:

[Bigfishtinny]

LOL thats the one!!!!! Mine used to be green, with an old 55yamaha(very reliable engines) on the back, BTW is that a Suzuki on the back?? looks like the one i am having fun with at the momment :D

[Bigfishtinny]

Just remembered mine used to leak so bad i had to get someoen to go to the front of the cabin just to get it to plane and there was no apperent reason for the leak :confused:


Gave us a lot of fun times it did though :P

[Wynand N]

BTW is that a Suzuki on the back?? looks like the one i am having fun with at the momment :D

good spotting and some humor intended - it is indeed a Suzuki 65 on the tail;)