1989 DT85 won't stay running under load?

[Andy Hatch]

My boat is a 1990 Key West 17'6''. Powered by a 1989 DT85. She runs great, at home. At the ramp, not so great. First it just wouldn't stay running. Cleaned carbs. Then it would still stall. Fuel lines had air leaks. Changed lines and primer ball. So on and so forth. All cylinders have great compression and I just can't seem to figure it out.

I've cleaned the carbs, replaced all fuel lines, removed the tank from in the floor and cleaned it, replaced shifter and throttle cables, replaced throttle control module, replaced fuel pump diaphragms, replaced under cover inline filter and cup, installed a water/fuel separator with clear jar and drain, and it still falls on its face when put under a load.

I've done all of the obvious things that I know to do. And then some. If anyone has any other ideas, please throw them at me. I'm up for the challenge, just keep running into the same wall.

Thanks, Andy

 

[waffles1]

Re: 1989 DT85 won't stay running under load?

Have you checked the throttle sensor?

 

[Andy Hatch]

Re: 1989 DT85 won't stay running under load?

Is that located on the middle carb? If so, I replaced it. It wasn't holding a setting.

 

["G"]

Re: 1989 DT85 won't stay running under load?

OK I'll ask... What is a 1989 DT85? Is it an I/O... outboard... and what make? 2 stroke/4 stroke, # of cylinders.... ya know, all that pertinent stuff.

Middle carb throttle sensor is indicative of an outboard. I'm still lost and can't offer any help w/o more info.

 

[Andy Hatch]

Re: 1989 DT85 won't stay running under load?

Its a 1989 85 HP suzuki outboard. 3 cylinder 2 stroke motor. Throttle Valve Sensor Assembly is located on the middle carb

 

[waffles1]

Re: 1989 DT85 won't stay running under load?

Andy, when you replaced the throttle sensor did you linc and sync the carbs according to the manual?

 

[Andy Hatch]

Re: 1989 DT85 won't stay running under load?

waffles1.......now your talking!

This repair was done in the past by the repair shop. But since then I've had the pleasure of cleaning the carbs three times. Just for good measure. And I've performed all of the other repairs myself.

Is a manual required for the sync and link operation? All others have not needed such instructions, yet!

 

[waffles1]

Re: 1989 DT85 won't stay running under load?

A manual would be of great assistance to you. Do a thread search. I had a thread on this for a 1988 which is probably the same. The guys in here were good enough to put the specs in that thread so you should be able to use those specs. If you have a constant miss at low to mid rpms but runs btter as you raise rpms this could be the problem. Good luck.