Single Cylinder repair on 1995 200hp Venom

I recently had my fuel pump repaired at my local dealer. I was having issue with proper fuel mixture and was using twice as much oil from the VRO as necessary. Dealer replaced fuel pump and I took the boat for a test drive and the motor was idling perfectly and had great power and ran well at WOT for approximately 10 minutes. The tach never read over 5300 rpm. The problem occured at WOT. The engine slowed down completely but did not stop running. I proceeded back to the landing and during the drive back to the landing the motor lost rpm's again. As I neared the landing I heard a strange rattleing sound. I returned to the dealer where upon inspection it appears I now have a failed cylinder. The dealer said he could repair a single cylinder provided all the other cylinders looked fine. Is this possible to repair just a single cylinder and have a properly performing engine. Obviously, the carbs will need to be cleaned as well since that is likely the source of fuel starvation to the one cylinder. Please help.

Re: Single Cylinder repair on 1995 200hp Venom

Single cyl repair is not uncommon.
It also depends how bad it was damaged and what else may be hurt as well.
If a piston came apart, there could be some port damage, and possible rod and lower bearing FOD, which is something that a tear-down is the only way to find.
If a bore job is needed, it'll require the over-size piston that matches how much material needs to be removed to clean it up, then up to the proper over-size piston. This will be a slightly larger piston but they are designed to weigh basically the same as a std piston so balance is not as much of an issue.
Depending on how much time you have on this engine, you may want to consider a hone or even a bore job on all 6 and go back with new piston assemblies and bearings....it's all in what you expect for life-span of this rig weighed against the cost.

Re: Single Cylinder repair on 1995 200hp Venom

Thanks for the quick response Walleyhed.

I don't believe the damage is too bad as it still starts and idles fine with only a minor amount of noise. In fact, on the muff it was difficult to hear any chatter from the failed cylinder. Loss of compression on that cylinder and the spark plug was dry. I am in the process of preparing the boat for sale and want to make sure it is right, but don't want to put more into than I have to make it perform for a potential buyer. It has low hours overall and is mechanically sound otherwise. This is why I posted the question about repairing a single cylinder. I don't want to sell something that is not expected to run well.

I am really confused why I would have a cyclinder with this problem after I have been running for a couple of weeks without any problem other than the fuel pump started getting progressively worse. I noticed that I was using additional oil and the last time I was out I ran a gallon of oil while consuming 21 gallons of fuel. Pulled wakeboarders and ran wide open without any issues. Idle and at times advancing the throttle resulted in the motor choking out and stop running. I couldn't get the boat into the dealer until this past week to check out. Dealer suggested that there must of been something stuck in the carburetor (carbon) and starving the cylinder of fuel. Shouldn't they have checked to see that I was getting fuel and oil to all cyclinders after the fuel pump was replaced? Thanks!

Re: Single Cylinder repair on 1995 200hp Venom

carbon would tend to go the other way, out the exhaust side.
carbs tend to gum up from lack of use , crap fuel or FOD that gets past filters.