High speed skip, 1996 150 Fast Strike

[1986mariner150]

Hey folks and thanks for looking at my post. Being a sucker for a good deal I have ended up with another boat. This one has a 1996 150 Fast Strike Johnson. I took it out today for the first time and was impressed by the power, but at wide open it feels like the prop slips for about a 1/2 second, almost like that feeling when you hit a stick and the prop slips while the skeg goes over it. It did it 3 times in about 3 miles. What could cause this? I change the lower unit lube and there was no metal on the magnet, the oil was a browinsh color. Also had a magnet on both screws. This is my first hot foot boat, I was wondering do I need to pust the hand throttle all the way foward when blasting? This is also my first jack plate boat is there anything different about driving a jack plate boat?

 

[OBJ]

Re: High speed skip, 1996 150 Fast Strike

Hi 1986....if I read your post right, the engine revs high every once in a while at WOT? Maybe your sucking air into the prop. Have you tried trimming in a little?

 

[rickdb1boat]

Re: High speed skip, 1996 150 Fast Strike

If the trimming doesn't do the trick, lower the engine with the jackplate 1/2" and see if that improves it. If so, you've found your problem.

 

[clanton]

Re: High speed skip, 1996 150 Fast Strike

If the engine is misfiring, check for coil arcing from coil to metal plate between power pack and coils.

 

[1986mariner150]

Re: High speed skip, 1996 150 Fast Strike

Hi and thanks for the replys. I dont notice any change in rpm. And it is not cavatation. It feels like maybe the clutch dog comes unseated just one notch and it happens so fast the motor don't seem to notice. Most of you know that feeling you get when you hit a stick while on plane, it just hesitates about 1/2 a heartbeat. I also thought the prop maybe was trying to spin the hub as it is nicked up but when I took it off it looks fine. The prop nut was a little loss, does this leave end play in the prop shaft which could cause the clutch to slip? My other guess (hope) is that the hand throttle (gear shift) got out of ajustment when the hot foot was installed, and not engaging the clutch dog fully. Any of this sound plausable? It deffinatly feels like prop or lower unit.

 

[muskyone]

Re: High speed skip, 1996 150 Fast Strike

all i can tell you is i have the same moter mine does about what your saying when i have the jack plate two high you have a great moter there i love mine tons of power and so far mines been vary relible i did tear up the lower unit but that was my fault when you shift that moter do it like you mean it lower your moter a little like rick says give it a run let us know

 

[1986mariner150]

Re: High speed skip, 1996 150 Fast Strike

I took the prop in to get it cleaned up and the guy showed me it was bent. I have another 24 raker that is pristine so I strapped it on and went out, same problem. I brought it back home and got to looking at that jack plate and found it was nearly (within 1/4 inch) from the bottom so I lowered it all the way and dropped the motor to the top hole, it was on the second from top. This lowered the motor about an inch, anti- ventilation plate about 2.5 to 3 inchs abbove the bottom of the hull. Tried her out same thing. My speed was down about 5 mph as well. I noticed the gas gauge was getting a little low so i switched it over to the port tank and headed in. Putting it on the trailer it was stumbling when I was trying to get up to the bow eye so I pushed it off the trailer and parked the truck and went back out to clear the carbs. My high speed skip was gone, along with about the last 500 rpms, Still indicating 65 mph and sounds like it is at full song but the tach is saying 5200 instead of it's usual 5800. I am thinking I have a faulty tank switch, bad gas or something floating around in the lower unit that is getting caught between the clutch dog and foward gear that has either found its way to the magnet or some other out of the way place, It feels like the latter but I can't see why it only does it at top speed or real close to it. I bought it back home and raised the motor back up to where it was to try and get my 500 rpm and 5 mph back. I will drain the lower unit again and hope I find a chunk on the magnet. I will put as much fresh fuel in as I can and hake sure that switch vavle is all the way one way or the other and try again. I will let ya'll know how it goes.

 

[muskyone]

Re: High speed skip, 1996 150 Fast Strike

what kind of boat is this on

 

[1986mariner150]

Re: High speed skip, 1996 150 Fast Strike

1996 Sprint Pro 277= 17'7" bass boat. I took it back out yesterday and have noticed the problem seems to be much more prone to happening on the first blast. After the first blast it may or may not do it anymore and if it does it ususlly only does it once, kinda like the motor sneezes or stumbles. I was wondering, do these motors have rev limiters? That would explain things totally. Except it feels like a mechanical hitch. I have the gear case off of it now, have also taken the gear case off the 130 V4 of the same year. I thought about swapping them out and trying it but the drive shafts are right at one inch different with the 150 being shorter. If someone has a mid 90's 150 gear case laying around I would really like to know the distance from the top of the water pump housing seal to the tip of the driveshaft. Thanks again for all help and intrest.

 

[1986mariner150]

Re: High speed skip, 1996 150 Fast Strike

Update: I took my lower unit to the shop for pressure test and refill and to let a more experienced hand check the feel of things and all was well there in his opinion, he is just as stumped as me on this high speed skip thing but he did mention one customer had a V-6 merc that was acting simular and it turned out to be a hitch in his bracket, So when I got home and strapped the LU back on I grapped the trim tab and starting moving it up and down and sure enough there was play. Turned out the bearings in the pivot tube were completely dry and was letting the motor move so I shot grease in until it staring coming out the end and that seems to have taken all the play out of it. Think it is worth a trip to the river to test or just wishfull thinking?