1994 Four Winns Fling (2024)

Re: 1994 Four Winns Fling

Welcome to iboats. <br /><br />That's basically an old Johnnyrude 90 degree 115Hp powerhead. You can replace just one piston, even if the cylinder needs boring. Pistons are the same weight, even if oversized. It's your option to replace the rings on the rest. But if you don't, you don't need to hone those cylinders. I would.<br /><br />You'll need to winterize that motor. The exhaust retains water in the casting below the powerhead and needs to be drained. That's the only jet I'm aware of that needs such attention. There are drains (plural) beneath.

Re: 1994 Four Winns Fling

Thanks for the great info, I look forward to more replies!<br /><br />Where are the drains I need to check or drain? You say beneath so I am assuming on the bottom of the motor somewhere? In the motor compartment or under the boat?<br /><br />Thanks Again!

Re: 1994 Four Winns Fling

Welcome!!<br /><br />Yes, that is an Evin/John powerhead. Basically just a V4 crossflow. Should have the "bubble back" exhaust. <br /><br />There can be any number of reasons one cylinder took a hit. Yes, you can repalce one piston and re-ring the rest. IF the cylinders are in spec. You wont know that until you get it apart and have them measured. Dont worry about how they look -- go by the measurements.<br /><br />The most common thing for a Turbo Jet is overheating. Folks tend to run them in very shallow water and up on a beach. That fills them with sand.<br /><br />Tell us more about what the cylinder and piston look like. What plugs were in it?

Re: 1994 Four Winns Fling

The cylinder with low compression (around 75psi) is the top right side (when looking at the boat from the back).<br /><br />You're saying when I get it tore down to take it somewhere and have the cylinder(s) measured? Is this something I can do with calipers or would this not be accurate enough?<br /><br />What is a bubble back exhaust?<br /><br />Another question:<br />Should the bilge pump, blower, and lights work without the motor running?<br /><br />Not sure I if I am going to tear down the motor yet this year or wait until after winter. Whenever I do I'm sure I'll be here with more questions and results. <br /><br />Thanks for the warm welcome,I look forward to my new adventures as a boater with everyone here to answer questions and help out, I hope I have the chance to help some people out as well!<br /><br />Joe

Re: 1994 Four Winns Fling

Joe,<br />I have the same setup on a Rage Boston Whaler. There are a lot of posts about your setup on continuous wave.com?search for boston whaler and you'll find it.<br />Have had my jet for over six years. The two petco*cks on the rear right side bottom should be drained after you are done running the engine for the season BUT!!!! you can still have major engine damage if you do not use antifreeze as pockets of water will remain after draining! Disconnect the water intake hose from the raw water strainer, add a funnel and pour in about 2-3 gals of marine engine antifreeze till it comes out the exhaust. The engine does not have to be warmed up. Also disconnect on of the top hoses running into the muffler from the cyl head and watch for the antifreeze to make sure the antifreeze is on both sides of the thermostats. Do not use the pink RV stuff as the alchol in it will rot your cooling and exhaust hoses. Poor some in the bilge around the base plate. Hope for an early spring.<br />Good luck.<br />Larry

Re: 1994 Four Winns Fling

Not calipers, bore micrometer. Measure in several directions 90° apart, as a miniumum, then average. Consult the OEM shop manual for tolerances.<br /><br />Bilge pump yes, blower probably not and lights no, but the bilge pump w/o motor running ONLY if wired though an automatic pump switch. The idea is not to run the battery down, but also keep the boat from sinking.

Re: 1994 Four Winns Fling

bilge pump,blower and running lights will work with the engine on the work bench. they are wired independant of the engine wiring.<br /> otherwise why put a tag on the dash stating to operate the blower for 4 min before starting engine ?<br />however the Hull wiring harness must be attached to the battery somehow, either at the batt or batt switch. usually there is a terminal/fuse block under the dash for hull wiring functions.

Re: 1994 Four Winns Fling

Thanks for all the pointers, I think my first step will be to order the service manual for the engine. <br /><br />As far as the fix goes I think I am going to try to get away with just fixing the one cylinder, I have read where people have done this and had a good running motor still five years later, at the same time I have read about people who have done this and then the motor went bad again right away?<br /><br />Thanks to everyone for the help, I'll post more when I actually start the work.<br /><br />Joe

Re: 1994 Four Winns Fling

the bubbleback exhaust is simply the exhaust cover between the cylinder banks has a big "bubble" on it, versus being flat like my '77 Rude 85hp. my guess since I don't know anything about them is that it acts kinda like an expansion chamber.

Re: 1994 Four Winns Fling

You said the compression on the bad cylinder was around 75psi, what was the compression on the other cylinders?<br /><br />The reason I'm asking is that if you only do the one cylinder what kind of variance will you end up with between that one and the others. Might be a cause for concern to if you end up with a disproportionately high psi in one cylinder over the other three.

Re: 1994 Four Winns Fling

The other three cylinders all range between 120-130psi. What psi should I expect if I only do the one cylinder?<br /><br />I believe the psi between cylinders (when done) should have a variance of no more than about 10% between the highest and the lowest correct?<br /><br />Thanks again,<br />Joe

Re: 1994 Four Winns Fling

Joe, 10% os correct, as to what the psi will be in the rebuilt cylinder my guess would be as high as 160psi, maybe a little higher.

Re: 1994 Four Winns Fling

One last question.<br /><br />Can I run the motor with no hose hooked up for a few minutes or must I have water hooked up for running the motor at all?

Re: 1994 Four Winns Fling

Joe, <br /><br />Even running without the hose for 5 or 10 sec can destroy the impeller