Need help with Suzuki 2000 DF70

[johnrdeaton]

History on this problem. In Feb I put the boat in for annual service, oil change, tune up, change lower end oil. I took the boat out and every time the rpm would reachs around 2500 the motor would start cutting out and could not get up on plane. Once in a while it will run perfect. I have had it to the shop EVERYweek since feb for the same problem. They have emptied and cleaned the gas tank, replaced the fuel filters, the injectors, plugs twice The last two times I have had it out the rpm will not go above 4000. The last thing the shop did was replace the plugs. The thing that really gets me is at the shop the boat runs perfect. I take it out on the lake and it runs perfect at 6000 rpm. I leave the shop and go fishing a couple of days later and it does the same thing, hits 2500 rpm and cuts out or won't go above 4000 rpm.
The motor is on my 82 Skeeter SF150. I love the boat but the motor is driving me nuts!
ANY help you can give me will be greatly appreciated by myself and older brother.

 

[JB]

Re: Need help with Suzuki 2000 DF70

Take it to a different shop. Ask for training certification on the DF70.

Changing parts is not an acceptable substitute for diagnosis.