Suzuki 85 hp outboard throttle problem?

Andy Hatch

Cadet
Joined
Jan 29, 2009
Messages
13
This may be long but I'm out of ideas. I'm laying it all on the table! Ready?

I'm the proud owner of a 1989 Key West Dual console boat. Powered by a Suzuki DT85. 85 HP suzuki outboard that has great potential. But this motor doesn't seem to like me. I recently posted on this same topic and motor runs the same. I'm out for blood with this thing. This motor won't give me the time of day.

Here's the situation:

When this boat is sitting in my yard, it starts and runs great. Throttles up and down in forward and reverse. Idles fine. No problems until I get down to the ramp to do a sea trial. PROBLEM! I leave the boat on the trailer in the water. I start the motor, and let it warm up. 4 to 5 minutes later when I put it in forward gear it stalls under any load at all. It wants to go but just won't.
I can idle away from the dock and go anywhere under idle but anything more than that she stalls. I'm stuck! If anyone has any ideas or knows someone who knows of something that could help please, and I mean please let me know. I've already spent more or trial and error on my own and with repair shops than its worth. I love the boat but she loves someone else. I guess?!?

Here's what I've done:

cleaned carbs (all three carbs, jets, and passages) no build up, new throttle cable, new shifter cable, new throttle positioning sensor, rebuilt the fuel pump ( diaphragms and such), pulled the fuel cell and cleaned really well and reinstalled, changed fuel lines, changed primer ball, installed a water fuel separator, clean and inspected inline fuel filter, new spark plugs, new coils and wires, adjusted all three carbs to manufactures specs, changed gear oil and lower unit components, and even went through all other possibilities that I know of. Not that there are many left but, something must be able to fix this motor.

This motor has put me in check. Over and over again and I'm a different person now. I'm mechanically inclined on all of the basic tuning and maintenance procedures. Any thoughs will be appreciated.

Thanks for taking the time for reading this and I take any suggestions.

Thanks, Andy
 

Andy Hatch

Cadet
Joined
Jan 29, 2009
Messages
13
Re: Suzuki 85 hp outboard throttle problem?

No. What should I be looking for? Just wear marks or torn areas? How can I tell if they are bad or not? Thanks
 

deejaycee_2000

Captain
Joined
Mar 28, 2006
Messages
3,447
Re: Suzuki 85 hp outboard throttle problem?

take them out and see if the plates are all looking in good shape .... you will see if a reed looks dodgy ......
 

waffles1

Petty Officer 1st Class
Joined
Jul 15, 2008
Messages
260
Re: Suzuki 85 hp outboard throttle problem?

Andy, when you replaced the throttle sensor and cable did you do a link and sync according to the manual? How was the motor running before you id the work on it?
 

Andy Hatch

Cadet
Joined
Jan 29, 2009
Messages
13
Re: Suzuki 85 hp outboard throttle problem?

The sensor was replaced by a repair shop. I replaced both shifter and throttle cables when the shifter cable broke and left me stranded in the river. I got back to the dock 2.5 miles in the backwards motion. Yes thats right. I drove back in reverse. Funny.
No manual needed up to this point. I guess if I'm to proceed any further I need one to pick one up. The boat ran great until it got water in the fuel and the carbs needed to come off. Bad seal on the gas filler cap. And thats where it all began.
Thanks
 

waffles1

Petty Officer 1st Class
Joined
Jul 15, 2008
Messages
260
Re: Suzuki 85 hp outboard throttle problem?

Reverse? that is funny. I would have pulled the cowling off and tied a stringe or rope to the throttle linkage and tugged on it to go. lol. It sounds like you may still have some kind of fuel problem. Good luck.
 

reeldutch

Lieutenant
Joined
Feb 2, 2004
Messages
1,340
Re: Suzuki 85 hp outboard throttle problem?

sounds to me that if the carbs are indeed clean and the tps is set in the propper range and the timing is indeed advancing and all the linkage is correct, you have isseus that are hard to find.

i would double check the TPS they are very sensitive and need to be in range .
it controls the timing.
dont mess with it if you dont have a meter and a service manual.

thats what i would do first before tearing into the engine and blame a seal.

good luck
 

Andy Hatch

Cadet
Joined
Jan 29, 2009
Messages
13
Re: Suzuki 85 hp outboard throttle problem?

Thanks to all. This has been rough to go through with my wife in my ear saying your doing it all wrong and that makes me double check my own work. She's got no faith. I'll get it....soon?
 

ssb33r

Seaman Apprentice
Joined
Aug 23, 2009
Messages
36
Re: Suzuki 85 hp outboard throttle problem?

you prolly did this but my buddys did pretty well the same thing, it turned out to be the quick connect fuel fittings
 

Xerxe37

Recruit
Joined
Aug 10, 2011
Messages
1
Re: Suzuki 85 hp outboard throttle problem?

I recently got an older boat with this same motor and it is doing the same thing. It runs perfect out of the water, but as soon as I put it in the water, I have to give it alot of choke and then immediatly put it into gear to get it to run, otherwise it just stalls out. Once its running as long as I go faster then 7 mph then its runs great. Did anyone find out what causes this??
 

James R

Commander
Joined
Feb 1, 2007
Messages
2,660
Re: Suzuki 85 hp outboard throttle problem?

It is most likely fuel supply. It needs more fuel under load. However it is best to start at the beginning. What does a compression test show. What does a spark test show. Are all cylinders firing. When you try to bring the rpm up under load try squeezing the the primer bulb, could be the fuel pump.
If you think it is a TPS problem disconnect it. The electronics will adjust to a nominal setting.
Xerxe37 please start your own thread.
 
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