Problem with my DT65

[du3443]

Good morning everyone,
I am new to this site and in need of a little advice.
I just purchased a 1987 DT65 for my pontoon knowing that it didn't run. I completely rebuilt the carbs and cleaned them in a carb cleaning solution for 24 hours each carb and blew out all of the jets and openings. I replaced the fuel pump and the spark plugs. I checked the spark and I get a good spark on all three cylinders. I am getting gas to the carbs and the bowls and float and needle are working great. I am kinda lost on where to go next. I have tried to start the motor to no avail. Any suggestions would be greatly appreciated.
Thank you,
Dusty

 

[cousinabe]

Re: Problem with my DT65

have you tried to spray a gas/oil mixture down the carb throats to see if it fires that way?

 

[du3443]

Re: Problem with my DT65

I havn't tried that yet. I will do that in a few minutes and see what I get.
If the kill switch had a problem would I get spark at the plugs? Just wondering, I replaced the ignition switch but I didn't replace the kill switch. Just a thought.

Thanks,
Dusty

 

[Silvertip]

Re: Problem with my DT65

You do not replace parts because you "think" they might be bad. You test them or diagnose the problem. No -- if you have spark the kill switch is not the problem. Are you using fresh fuel? Did you pull the plugs to see if they are wet with fuel, dry, or what. Dry says its not getting fuel. Wet says its flooded which probably means weak spark -- not good spark. Have compression tested this engine?

 

[deejaycee_2000]

Re: Problem with my DT65

Do a compression test .....

 

[du3443]

Re: Problem with my DT65

Ok, Thank you all very much for you input so far, this is what I have done, I took the advice and before replacing things that I didn't know if they were broken and I did a continuity test on the kill switch, that is functioning correctly. (Thanks Silvertip for slapping me across the face and making me do what I know is right) Next I took deejaycee_2000's advice and did what I also should have done at the beginning and did a compression test, and what do you know, Cylinder 3 has 5-20 psi while 1 and 2 get 125psi. I am an idiot, I can't believe I didn't even check that from the beginning. So now what I have is another question. I have rebuild a couple of Chevy Small Block engines, a 4 stroke Honda four wheeler engine, but never and outboard or a two stroke like this one. My question is, Can I do it with the knowledge I have and a Clymer's book. Or do I need to get this to an outboard mechanic? I would like to do this for as little money as possible, I have the DT65 that I am working on now and I have a DT55 that I stole the lower end from that is complete minus that and the carbs that I could use for any parts that I would need. I got both motors for $100 so I don't feel like I got ripped off but I would like to make one complete motor from them. Any advice will be appreciated again.

Thank you,
Dusty

 

[sturdavj]

Re: Problem with my DT65

Go for it.

http://store.brownspoint.com/pdf/DT65

 

[James R]

Re: Problem with my DT65

DU. Has this motor been in salt water? If it has you will be in for a bolt breaking experience and you may be better off junking the motor. Suzuki,in their wisdom, used poor quality stainless bolts, if they are stainless that is.
Doesn't hurt to try a few bolts. You really wont know what you have untill you open it. A Seloc or Clymer manual will suffice for what you need to do.

 

[du3443]

Re: Problem with my DT65

Well thanks guys,
It has been in some salt water, however I just had a thought, I have the motor that the lower unit came off of and the Head is already pulled off of that, I could slap that back together and see what I get, The only difference in the two moters is the one I stole the lower end from is a 55 and this is a 65 but from what I can read the only difference is the Carbs. What do you all think, I guess I can try to break a couple of bolts free to see what I would be getting into.

Thanks,
Dusty

 

[du3443]

Re: Problem with my DT65

P.S.
Just a quick question for my own curiosity, What usually causes that big of a drop in compression from one cylinder to the others on a two stroke like this?

 

[cousinabe]

Re: Problem with my DT65

Low compression could be caused by bad piston rings, a bad head gasket, bad valves, or all of the above.

 

[du3443]

Re: Problem with my DT65

Well I got the Head off and found at least one of the culprits. The Head gasket is blown out on the bottom cylinder. Now to the next question for you experts, That is obviously a problem but should I go ahead and strip it down and rebuild it all or leave well enough alone since I didn't break any bolts so far and just replace the Head gasket and see if that solved my problems or go ahead and slap the other power plant from the 55 back together and see what I get. Let me know what you think.

Thanks a lot everyone,
I would have probably pulled my head out if it were not for all of your advice and patience.

Dusty

 

[cousinabe]

Re: Problem with my DT65

I would reinstall the head with a new gasket and do a leak down test.

 

[James R]

Re: Problem with my DT65

With the head off you can inspect the cylinders for scoring. If any of the cylinders are scored the motor will need a rebuild. If no scoring go with the gasket.

 

[deejaycee_2000]

Re: Problem with my DT65

i agree with james, do not make too much work for yourself, inspect the cylinders closely for scoring and make sure the rings and the piston is still in good condition, if all is well only replace the gasket ....