DT 55 weird things

L

loadedaxe

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Jun 28, 2005
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Hi guys, I need a little help and steerage.<br /><br />I have a 1988 DT 55 that I bought on a boat last week, I take it out and it idles ok but sometimes dies when when accelerating in forward or reverse, wot is ok. I got it home and hooked it up to the water hose and ran it to flush it out, and noticed fuel/oil leaking from the prop after shutting it off, this trickled out for about 5-8 minutes. The guy I bought it from said run 24:1 in gas tank along with the oil injection for safety reasons he always did that to keep from screwing it up if the oil pump ever stopped. I wonder if this will make it run poorly and cause the unburned leakage.<br /><br />Also, I noticed the water pee hole wasnt squirting water on the hose, it was in the lake though.<br /><br />Any ideas are greatly appreciated.
 
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cpj

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Jun 14, 2005
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Re: DT 55 weird things

As for the pee hole not squirting,make sure that the muffs are covering the water intake and that you have adequate pressure going to it.Im not a suzy guy, but a bad fuel pump could be the cause of the fuel/oil leak.If the pump diaphram has a hole in it,that would cause excess gas to leak into the crankcase,which in turn could cause poor running conditions.(thats the case for yammys any way)It can also wash the oil off of the cylnder that the pump is connected to on an oil injected motor.Which is not a problem in yours since you are also premixing.That being said,mixing at 24;1 is doing nothing more than fouling plugs and causing excess carbon buildup on your motor,and lining the pockets of the already fat oil companys.If you want to add the oil to your gas as a safety measure,then mix it at 100:1.On a side note,a quick way to check the fuel pump is to remove it from the motor(with all lines attached)and squeeze the primer bulb and see if any gas runs out the back(motor side)of the pump.If it does a new pump is in order.And if you dont know the history of the motor, it might not be a bad idea anyway.Thats my 2 cents worth, now lets hear from the experts.
 
B

bossee

Senior Chief Petty Officer
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Jul 18, 2002
Messages
727
Re: DT 55 weird things

Hi,<br />With DT55 1988 check that You use NGK B8HS-10 spark plugs and gap of 0.9-1.0 mm / 0.35-0.39 inch.<br /><br />The Suzuki oil injection system works with variable fuel:eek:il ratio. At idle it is 150:1 and at full throttle (WOT) 50:1.<br />As safety you could perhaps use 100:1 in gas tank in combination with a oil injection system in use but it will be rather much oil.<br /><br />I would check the fuel pump also, the rubber diaphragm set (just buy new, not expensive).<br /><br />There is also carburator kit (about $20 each so total $60), You get new needle valve + seats and gaskets. You may want to check the floats are in good shape also and make sure they are adjusted in height according to specification (0.39-0.47 inch)<br />See picture in this thread:<br /> http://www.iboats.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=30;t=006000
 
L

loadedaxe

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Messages
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Re: DT 55 weird things

Hi, thanks for the quick responses.<br />I pulled the plugs out, and they are in bad shape, black carbon is extremely bad, which I am assuming is from too much oil. I am going to install new plugs and run the gas with no oil, however, how do I know if the oil is pumping properly from the injectors?<br /><br />I cleaned out the pee hole (blew compressed air through it) and pulled the thermostat and cleaned it all up and the water flow is good now. The plugs were gaped at .032 which is probably why it didnt run right. Once plugs are installed and gapped properly I will post again. You guys are awesome! Thanks!
 
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cpj

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Re: DT 55 weird things

I dont know on a suzy. :confused: On a yammy you can run the engine on premix and disconnect the oil lines and measure how much it is pumping, (ie so much oil per certain amount of time)I would assume that you could do that as well on your motor.Did you check the fuel pump
 
L

loadedaxe

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Re: DT 55 weird things

I havent checked the fuel pump as of yet, its raining right now and I was going to test it once I got a clean tank of gas, as I already ran it with the gas disconnect to empty the bowls. I will do so in a bit and repost.<br /><br />On another note, I filled the oil res. all the way up last week, after running 7 gallons through it, it has used about 1/3 of the oil so far.
 
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cpj

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Re: DT 55 weird things

I would say that the oil injection is working then.One thing that I would suggest is looking at the faq section here at I boats and follow the instructions for decarbing.If it has been run with that much oil,Im sure that it is due for a good decarbing.One word of caution though,warn your neighbors before you do it (or do it on the water) because it makes lots of smoke.Lots of mosquito killing smoke!Although down in your neck of the woods that wouldnt be a bad thing!I will be in Sarasota all this week for a fire alarm training class,which sucks cause I will be in Florida but wont be able to fish! :mad: But on the other hand I will get to enjoy some fresh sea food that you cant get here in Missouri.When they say fresh sea food in Missouri,they mean that it was fresh at one time or another. ;)By the way, did I mention that decarbing makes alot of smoke?
 
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loadedaxe

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Re: DT 55 weird things

LOL, Fire alarm training eh? What industry are you in? I am a service technician for a prominent Security/Fire Alarm company here. <br /><br />Anyhow, I got the new plugs in, clean gas with no oil, and it runs descent and still smokes....so I am assuming the oil flow is ok :cool: , the all-in-one gauge on the motor doesnt work so I guess thats my next money pit if I can find it, also the fuel pump does not leak, however, I might as well replace it as well.<br /><br />I see alot of people here on the forums talk about disconnecting the oil injection and go to pre-mixing...is that a good option?
 
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cpj

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Re: DT 55 weird things

I disconected mine.Its a 85 yam 115.I just didnt trust it.By prominent company, would that company have a name that is only 3 letters that starts with A? BTW I install security/ fire alarms for the above mentioned company.
 
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loadedaxe

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Re: DT 55 weird things

LOL, nope, Its a 10 letter company that starts with an A, I will give you a hint....we used to be Westec.<br /><br />I may do the same (disconnect the oil injection), Im a little leary about trusting it as well. This is my second boat, my other is a small 14' Fiberglass, 1973 Montgomery Ward Seaking with a OMC 18 hp on it. <br /><br />Thanks for all the input!
 
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loadedaxe

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Messages
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Re: DT 55 weird things

Actually...its only 8 letters......<br />Hint #2<br />The name of an ocean.....um....on the east coast. :) <br /><br />When you disconnected the oil injection, did you just cap off the inlets? I think mine has a safety switch on it that kills the motor if it is low on oil, hence, I would have to disconnect all that, right?
 
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cpj

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Messages
958
Re: DT 55 weird things

Never heard of it.But since you cant count letters that explains why you are a service tech. :D (just kiddin)I capped off the inlets and disconnected the wiring harness.The switches were all n/o,so by disconecting it, the controller thougt that all was well.I also removed the rod that connected it to the crankshaft.But I would ask a suzy expert about that.
 
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loadedaxe

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Re: DT 55 weird things

We've been around since '68<br />LOL, yeah, at first I counted the letters on my fingers, which explains why I am not a installer! :) <br /><br />I think mine are all n/o switches as well, Im going to give it a try tomorrow and see if it will run. The gauge is always beeping really quiet...but, I cant tell what its beeping about as the lights on it dont work, water flow is good and I rarely run it wot as my boat is only a 15' fiberglass, wot runs me about 40 mph...thats a little scary for me on a 15' fishing boat! :)
 
B

bossee

Senior Chief Petty Officer
Joined
Jul 18, 2002
Messages
727
Re: DT 55 weird things

Hi,<br />If You want I can e-mail You the electric wiring diagram for DT55 1988. That way You maybe can get the warning guage (Temp, Oil, Oil level, Rev limit, Check engine) to work (assuming it is not the guage itself that is defect).<br />I can also e-mail You the charts for Oil injecton and Owerheat warning system so You can figure out what your outboard is trying to tell You.<br />So If You want this, just write Your e-email adress here (if You want to avoid spam just write it "my name @ abcd dot C O M" or something like that).<br /><br />About using the existing oil injection system, buy a new pump or disconnect it:<br /><br />A Suzuki like Your DT55 will never run as good on premix 50:1 as it will with the variable oil injection system (150:1 at idle to 50:1 at WOT). At lower RPM it will get a to much oil.<br />A new oil pump cost about $162 (according to brownspoint.com )<br />As You can imagine it is both the pump itself AND the houses and connections from pump to carburators that are equal important. A bad house or connection that breaks is disaster on that cyl. Check the parts listing for DT55 1988 at brownspoint.com and You can see the weak spots in oil pump system.<br /><br /><br />/Bo
 
L

loadedaxe

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Jun 28, 2005
Messages
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Re: DT 55 weird things

Bo, that would be great. email me that info if you can to la @ loadedaxe dot com<br />I would greatly appreciate it.<br /><br />I dont know much about outboards and I would hate to make a costly mistake. Are these oil injection systems reliable?<br /><br />It seems to be running ok at the moment with clean gas and no premix in it, still smokes so I know the pump is working, however, I would rather spend a few bucks so I would know for sure. The guy I bought it from said hes never had any major problems with it, but like others, he just ran the premix to avoid costly repairs, running it without premix also stopped the drainage from the exhaust, at least it didnt drain after I ran it for about 10 min at idle when I cleaned it al up yesterday.<br /><br />Any help is greatly appreciated!<br /><br />ps, Im having a pisser of a time finding the all-in-one gauge as well, any ideas?
 
L

loadedaxe

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Jun 28, 2005
Messages
23
Re: DT 55 weird things

Nevermind, I found the same part number on Browns.<br /><br />I ordered the tstat, gasket, gauge monitor, fuel pump and oil pump.<br />One question, how hard is it to lift the motor up to install the oil pump :)
 
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