99 90hp Skip

[Stonefly1967]

This spring I had to change the transducer on my boat with the same model, it seemed a little high because I was getting a lot of spray off it hitting the rt side of the motor causing a skip above 30 mph. So I lowered down and the spray angle changed some but still hit's the motor, but the skip went away on 4 trips. I'm going to lean over and see for myself if the spray is caused by the transducer or the speed wheel, Now I fill up last weekend and get the skip back. I have a kicker I run trolling and have run that wide open on occasion to see if that would skip (water in the tank) and it doesn't. I haven't changed the plugs yet which I will do this weekend before heading out. It doesn't seem like the water hitting the motor should cause it to skip unless it was getting sucked into the air cleaner? When I pulled the hood off there was some small amount of water in the front of the motor, less then a soda bottle cap full, but we had hard rain just prior to me pulling it off.

Any suggestions??

 

[Dhadley]

Re: 99 90hp Skip

Any spray that gets around the middle to upper part of the mid section stands a real good chance of getting sucked in the air intake which is just below the bottom carb. We're not talking about a fire hose spray, even a mist will do it.

As the mist gets pulled in with the air and it enters the airbox some of the water will fall to the bottom of the air box. There it'll go thru that bottom hose and gets pumped into the reflow system. First the bottom bearing then to the top main bearing.

If you're getting enough water in the airbox to create a miss you're getting a lot of water. Correcting the cause of the spray is easy, seems you have a handle on that now. Getting the water out of the reflow system before it rusts the bearings may be a bit harder.

Run the motor, even if it's on a flushette, and pull the air silencer off. There's a hose going from the bottom main to the top. There should be a T in it. While the motor is running spray some lube in the T. If there is no T put the lube in the hose. Whatever you chose to use make sure you get enough in there to displace any water. Doesn't matter if you use outboard oil, DPL, fogging oil or whatever, just get enough in there. We'd use outboard oil.

 

[Stonefly1967]

Re: 99 90hp Skip

So you think the water is getting sucked in thru the air vent's at the top of the motor? Makes sense, I ran the motor one day when the lake was flat and it skipped so I took a piece of duct tape and taped off the air vent intake off on the RT side and ran it up to 40mph and it didnt skip and quickly took the tape back off and it did it. Funny thing is why is it doing it this year and not last year.....

I will try to do something with the transducer or speed wheel to get rid of the spray and also put some oil in that tube.

Thanks.

 

[Stonefly1967]

Re: 99 90hp Skip

Ok, Still at it with the skip.

Changed the transducer so know spray is hitting the motor, changed the spark plugs and still have a skip above 30 mph, no skip at all running up to 27 -28 mph, once it hits 30+ it will skip and almost fall on its face. boat tops out at 37 or so..

Any thoughts???????

 

[Dhadley]

Re: 99 90hp Skip

Will it miss with the hood off?

 

[Stonefly1967]

Re: 99 90hp Skip

I havent tried running it with the hood off, are you thinking it needs more air? Is there a fuel filter/screen on this motor. I added some Startron fuel additive to try to burn any water that maybe there too.

 

[Stonefly1967]

Re: 99 90hp Skip

Bump...

 

[Dhadley]

Re: 99 90hp Skip

Try running with the hood off.

 

[Stonefly1967]

Re: 99 90hp Skip

Ran with the hood off, still have the skip. Changed the fuel filter which was dirty, still have the high speed skip.

 

[Dhadley]

Re: 99 90hp Skip

Next time you run the motor hook a timing light to each spark plug wire one at a time. Watch the light and see if you can determine which plug(s) the miss is on.

What spark plugs are you using?

 

[Dhadley]

Re: 99 90hp Skip

Have you taken compression on the motor lately?