DT 85 RPM runs up for no reason.

[G S]

I have a '83 DT-85. Always ran great, got some bad gas, cleaned carbs. Now, for no apparent reason when I power back it will reve out of control. It doesn't do this every time. The linkage is not sticking. The only way to shut it down is either choke it or disconnect the fuel supply.

Any suggestions?
GS

 

[JUSTINTIME]

Re: DT 85 RPM runs up for no reason.

did u sync and linked

 

[pepperdoggy]

Re: DT 85 RPM runs up for no reason.

Did you ever get this fixed. I have the same problem. I bought a boat that had water in the gas. I cleaned the carbs and it runs good at times, but sometimes it won't idle and it runs off on occassion. The first time it did this it was on the hose. I turned off the key, pulled the killswitch, and out of despiration, pulled all 3 plug wires and it still didn't stop even with no spark. I then chocked it just as you did, to stop it.

Thanks

 

[bowhuntrrl]

Re: DT 85 RPM runs up for no reason.

Sounds like run on caused by too many carbon deposits. Either pull the heads and decarbon, or you could try the Seafoam method of decarboning.

 

[FM BEACH]

Re: DT 85 RPM runs up for no reason.

I just have the same exact situation as both of you. Ears are still ringing from engine winding out. Did the carbon cleaning thing work for anyone? How does that happen suddenly after cleaning the carbs?

 

[bowhuntrrl]

Re: DT 85 RPM runs up for no reason.

I just have the same exact situation as both of you. Ears are still ringing from engine winding out. Did the carbon cleaning thing work for anyone? How does that happen suddenly after cleaning the carbs?

Did you take the carbs off ?? If so, did you use new gaskets?? It may be possible that an air leak behind the carb would have the same effect as an open throttle.

 

[FM BEACH]

Re: DT 85 RPM runs up for no reason.

Did you take the carbs off ?? If so, did you use new gaskets?? It may be possible that an air leak behind the carb would have the same effect as an open throttle.

Yeah, the gaskets were pretty iffy. I would have left them intact and cleaned around them but someone must have been in there before, because the top two gaskets were on backwards so that the hole wasn't lined up and the gasket was covering 1/4 of the hole on one side. Anyway, a boat dealer acquaintance mentioned the float might be sticking, so I checked them all and the bottom carb float didn't look like it was pushing the pin in as far as the other ones, so I bent the tab up a little and the problem seems to be solved.

 

[bowhuntrrl]

Re: DT 85 RPM runs up for no reason.

Great, glad that you found the problem !!!