2004 Suzuki DF140 high revs won't shift only after warmed up

[rdnkbkr]

I've seen a couple of threads about hard shifting on the Suzuki df140, but none that match my problem. When I took my boat out a couple of weeks ago it ran fine from the ramp, nice easy shifting, no problems. Once I had done a wot run down to a fishing spot about fifteen minutes out, I tried to shift to neutral only to have the shifter refuse to go into neutral and the engine stayed at about twelve or thirteen hundred rpms. I tried working the shifter back and forth aa few times with no change and finally I was able to force the motor into neutral but it stayed at the high rpm. I could force it back into gear and accelerate all the way to wot and took the opportunity to get back to the boat ramp. When I got back it was the same thing, high rpm and hard shifting. Got it home and lubed everything thinking maybe i had a dry cable or linkage. Took it out again a few days later and it was acting normally, going to idle and shifting nice and smooth. Once I took off and gave the engine time to heat up it started acting up again, same issue, high rpm and not wanting to shift. I pulled the plastic off of the engine today and checked the cable and linkage with no resistance at all, I hooked up my hose and tried everything with the engine running and still no problems. If this problem only shows up after running hard am I looking at a clutch or gear box problem? Any help is greatly appreciated!

 

[99yam40]

my guess if there is something vibrating into a position binding up linkage.

Need to be looking for the problem while problem is there, not after trailering it back home

 

[rdnkbkr]

I'm planning on taking it out on my next day off and running with the plastic off so i can get to the controls. Then if it happens again I can disconnect the cables so i can determine if the fault is in the engine or the throttle/shifter control set.

 

[rdnkbkr]

Before taking it back out I pulled the cover and side panel off of the throttle/shifter controls just to watch the movement. I found a couple of small pieces of black plastic(?) In the grease around the moving parts, maybe 3/8 of an inch long. I removed these and moved the controls back and forth a few times but couldn't see anymore pieces anywhere. I've had the boat out twice and haven't had any further problems. I hope this is helpful for anyone else that may be in a similar situation. Thanks for the reply.

 

[AJ168]

It very well could be that the hard shifting is because of the higher rpms. It's not like in a car where there's a clutch to disengage the motor to make the shift, so shifting at higher rpms or quickly between forward and reverse will damage the gear case. You should try to refrain from shifting when it's idling that high, I'd be willing to bet you'll find some shavings in your lower unit oil from doing it just a few times.
The motor should not idle that high, something is wrong, either the linkage isn't returning the throttle back to idle, or something else, like a leak on the intake side is causing the computer to bump up the rpms. As far as troubleshooting that, you're stuck going to a dealer. The motor literally has it's own brain, and will need to be hooked to a computer, which will hopefully show a fault code. You could take a shot at replacing the t-stat, as a motor that's not coming up to temperature correctly will cause it to idle high, but that's just a guess at one of what could be several possibilities.