89 200 XP "Sneezing"

[Rude520]

Bought the boat and motor in November. This past weekend was the first chance I had to really get it out and run it. When I bought it compression was good in all 6 cylinders.

After warm up and running the engine and back to idle it has the sneezing. And also every now and then on take off it is a dog out of the hole. One time it almost acted as though it was not getting enough fuel. Plus at WOT it would only turn 5000 RPMs. Its on an 89 Stratos 201 and would only achieve 51 MPH on GPS turning a 23P Stlleto 3 blade. And while loading on the trailer the engine acted like it did not like being under load.

I have not checked prop to pad height or anything at this point. My big concern is fixing any problem before it causes others or engine failure.

To my knowledge from previous owner the only service done recently is water pump and LU grease change.

Sorry for no serial number I forgot to get it. Also the VRO has been removed and I mix the oil 40:1.

My question here is where would be a good place to start to diagnose and fix the sneezing and possibly the low rpm?

Again I have not ruled anything out. Just looking to you experts here on where to start.

Thanks

Chris

[ChampioNman]

timing would be a good place to start. Verify your idle timing with the motor warm and in the water with back pressure. Sneezing could be caused by a few things but I'd start by looking at the carbs. I would also inspect the throttle roller on the port throttle body. If there is just a hard black plastic roller then the clear cover roller is probably missing or has deteriorated. You need to make sure that the throttle plates are opening fully at wide open throttle. I would also remove one of the recirc valves and check its condition. They are a one way check valve that scavenges unburned fuel and sends it to the cylinders to improve idle characteristics. A quick test for the recircs is to run the motor on cooling muffs and raise the motor from full down trim to full up trim while watching the tach and listening to the motor. Any change in RPM's or pitch indicate plugged recirc valves.
40:1 is a little heavy for that motor 50:1 is the prescribed ratio. And use Champion plugs QL77JC4's gapped at .030".

[Rude520]

Could I just pull the carbs and clean them without buying the rebuild kits?? I am running a bit short on funds to get them. Was just wondering.

Thanks

[overdrivecb]

you may be able to clean them , but pay very close attention to all of the orings and if anything looks strange or weak replace it. a bad oring seal from carb-throttle body will cause all kinds of headaches. even if you do have to replace a few it will be cheaper than a carb kit. check the needles good too. also would be a good time to replace the drain screws with the updated ones if they havent been done yet.