1997 Four Winns Fling

[jboot2616]

I recently purchased a '97 FW Fling. It was a great price and I think I found out why. There does not seems to be any problems with the engine, but at an idle it keeps making a thump every x number of seconds. It almost sounds like a regular boat that is trying to engage the drive, but I don't think that is it.
It still seems to do this when the drive is engaged at an idle, but it stops when you give it the gas and go. It may still be there, but you don't hear it.
At this time I am thinking that this might be a bearing in the jet drive, but I could be way off.

Any ideas?

 

[RotaryRacer]

Re: 1997 Four Winns Fling

The thing you need to keep in mind is that with a jet drive...any jet drive, the jet is pumping water any time the motor is running. The only thing you can do to put it in "nuetral" or "reverse" is to block the outlet of the nozzle to either redirect or limit the amount of forward thrust you have.

This noise could be many things. You can hear it at idle, however, if you come just above idle does the noise get louder or faster?

Does the boat perform at speed as you would expect? Does it accelerate smoothly and continue up to a reasonable speed?

 

[njlarry]

Re: 1997 Four Winns Fling

You have the same set up as a Boston Whaler Rage 115 (also was used by sea ray and others)
It is very common and no one seems to know why. It may be debris catching between the jet impeller and the housing. So long as the engine runs smoothly above idle speed you should be fine. Check that there is no corrosion in the housing "venturi" around the drive impeller. Keep a close eye on the cooling system as there really is no cooling pump and debris can clog the system very quickly. An oversize strainer from a farm tractor store is a good ideal.