1987Suzuki dt 175 outboard gas problems?

[Chrisandallison1213]

I have a 1987 Suzuki dt 175 outboard motor. We've had nothing but problems since we've had it. It seems like all of the problems we've had have been fuel related. It is hard to get it to crank and stay running, won't idle (we need to adjust the idle) we've taken the carbs apart and cleaned them. Replaced all of the gas lines but it still seems to give us problems. It's hard to crank. I have a fuel/water separator on it. A New primer bulb. New fuel filter. Is it possible the gas that I'm using could be the problem? Or the built in gas tank? Any other suggestions? We ran it out of gas one time and when we got more gas it would get to about 35 mph and then slow down to 30 mph for a couple of seconds then jump back up to 35. And occasionally it would do that again. We took it out yesterday and didn't have any problems other then it was hard to get it cranked.

 

[ondarvr]

So that we're all using the same terms, cranking is turning the key and having the starter spin the motor, starting is the next step. So I'm assuming you're saying it's hard to start.

​If the gas is fresh it most likely has nothing to do with the hard starting.

​Describe the exact method you're using to try and get it started.

​The change in RPMs at high speed can be from fuel delivery, or electrical, instant RPM changes that are like someone flipped a switch are normally electrical. If the RPM change is slower and smoother it's more likely fuel delivery related.

 

[Chrisandallison1213]

Correct it is hard to start. Gas is fresh. Once lowered into the water I lift the throttle up and attempt to crank the motor. The motor just won't start. After trying that a few times and pumping the primer ball a few times I put the throttle down and turn the key. Eventually it starts. Just takes a while.

 

[ondarvr]

I'm not completely familiar with that motor, but there should be some kind of a choke/primer switch or button, possibly pushing in the key, that you need to use for cold starts. Are you using it?

 

[Chrisandallison1213]

You can push the key in a little. Could that be it? Didn't think about that.

 

[ondarvr]

Yes, that's required for easy starting when cold. Make sure it works, there should be some clicking or moving of parts when you push the key in.

 

[Chrisandallison1213]

So if I take off the cover where the carbs are and look at it when I push the key in they should be completely closed right? If not then could it be sticking? Would that mean I need a new ignition switch? Or is there a way to just replace the choke? Sorry new to this part.

 

[ondarvr]

It may or may not be an actual choke like you might see on another motor, most have a primer system that bypasses the carb and dumps fuel right into the intake. This is a solenoid with a couple wires going to it, it would click when it opens and supply gas.

​The choke you can see working, the solenoid is tougher, you may need to pull the fuel line off on the carb side of it and see if gas comes out when you push in the key.

 

[99yam40]

looking at a parts break down on a DT175 I do not see a choke, but I do see what is called a starter valve assembly.
I do not know how it functions, but it does have a float, adjustment screw, and some electrical device.
might be like the Yamaha prime start enrichment system or maybe not
A service manual would be a good idea to get and read up on it

 

[Chrisandallison1213]

Okay. I am messing with it now. I took the cover off the carbs and when in neutral the "butterfly valves" are supposed to be closed right? Well if I move the throttle into forward they open up. When I move it back to neutral they don't close all the way. When I move it to reverse they open and then when I move it back to neutral they do not close all the way. If I lift the lever up then put it back down it does not close all the way either. Could that have something to do with it not cranking right?

 

[ondarvr]

Again, cranking or starting?

​Normally the butterflies should be closed when at idle, but I haven't worked on one of these before.

 

[Chrisandallison1213]

Starting. I messed with the idle a few days ago. From what I've read it could cause it to get out of sync and it needs to be re synced

 

[99yam40]

the throttle plates should close almost all of the way.
the motor still needs some air and fuel to idle