Force 85 HP- 26 MPH :S

[Big_C]

Ive got a 72 glastron starflite v165- 16' with a 86 force 85 motor

The motor runs and sounds great...but my gps tells me my top speed is around 26 mph. Seems kind weak for a 1000lb boat.

Any recommendations? I pulled the plugs after taking it out, and they were somewhat wet and fairly clean looking. My tach is not working, I am in the process of fixing that. I put a can of seafoam in the fuel tank for the next trip out. Prop is in good shape with no damage, although the skeg has a section broken off of it.

 

[further]

Re: Force 85 HP- 26 MPH :S

Definitly sounds too weak/slow. My 17' maxum bow rider w/ 88 85hp does about 35mph. Do the basics - compression test, spark test, and decarb if you haven't yet. Let us know how you make out.

 

[further]

Re: Force 85 HP- 26 MPH :S

Forgot to mention, you need to get your tach fixed so you could tell what your rpm's are - very important. what pitch prop are you using?

 

[MAXXIE]

Re: Force 85 HP- 26 MPH :S

I don't know if this will have any bearing on what your problem is ,but I have a 1985 Force 85hp o/b on 16' bowrider. The first time I took it out I could only get 20/22 mph (gps) out of it. The motor sounded fine, it just didn't have it. End result: plug wire was off. Now running 35 mph @ 3600 rpm . Just thought I'd drop my story.

 

[Big_C]

Re: Force 85 HP- 26 MPH :S

Thanks for the replies-

The ignition is fairly new, although the plug wires do look pretty cracked and are 20 years old. Gonna fix the tach, install new plug wires and decarb soon- will post back up with my findings!

Thanks again

 

[Challenger84]

Re: Force 85 HP- 26 MPH :S

any updates?

 

[erikpn]

Re: Force 85 HP- 26 MPH :S

Maybe the boat is full of water and weighs far more than 1000 lbs?

 

[Big_C]

Re: Force 85 HP- 26 MPH :S

It certainly is possible that the boat is full of water, I have no way of knowing.

The tach is not working for some reason...it is wired properly. Perhaps because there is now the 3 ignition boxes, the purple tach wire won't work?

I still plan on getting new plug wires to see if it will work. I decarbed it, and didn't seem to help much at all.

 

[jerryjerry05]

Re: Force 85 HP- 26 MPH :S

Do the basics first:comp/spark test.Then check the fuel pump diaphram.Post your results.J

 

[erikpn]

Re: Force 85 HP- 26 MPH :S

It certainly is possible that the boat is full of water, I have no way of knowing.

The tach is not working for some reason...it is wired properly. Perhaps because there is now the 3 ignition boxes, the purple tach wire won't work?

I still plan on getting new plug wires to see if it will work. I decarbed it, and didn't seem to help much at all.

Most glass boats that age are full of waterlogged foam and wood. Have you tried weighing it?

 

[canoboy1983]

Re: Force 85 HP- 26 MPH :S

hi, i have a 89 wellcraft 170 with a 85hp force and im only at 28mph. I decarbed and changed plugs. How much does my boat supposed to weigh and how do i check to see if it is watterlogged without ripping up the floor?

 

[jerryjerry05]

Re: Force 85 HP- 26 MPH :S

Do the basics first.Comp/spark then check the fuel system.J

 

[Big_C]

Re: Force 85 HP- 26 MPH :S

Is there any way to remove water if it is waterlogged, or is that a permanent problem?

 

[further]

Re: Force 85 HP- 26 MPH :S

BigC,
you really need to see what rpm's you're running. Get your tach fixed or pick up a tiny tach and see what your wot rpm's are. You should be running between 4500 and 5500 rpm at wot. There could be many reasons you're not getting good speed, one of which could be a waterlogged condition. Could also be wrong prop, carb adjustments, electrical, etc. Get tach, do compression/ spark test and post back.

 

[jkust]

Re: Force 85 HP- 26 MPH :S

85 hp Force on a 16 foot Bayliner, easily over 40mph on gps. You need to weigh it, my bet is water logged. I wonder what the dry weight is supposed to weigh. My Bayliner is 1050 lbs including the weight of the engine for comparison. Also, I don't have a tach.

 

[birdgod]

Re: Force 85 HP- 26 MPH :S

85 hp Force on a 16 foot Bayliner, easily over 40mph on gps. You need to weigh it, my bet is water logged. I wonder what the dry weight is supposed to weigh. My Bayliner is 1050 lbs including the weight of the engine for comparison. Also, I don't have a tach.

I have the same setting, I can only goes up to 32mph, I have 4 adults on it thought.

 

[Big_C]

Re: Force 85 HP- 26 MPH :S

One more important thing to note- my exhaust snout is mostly eaten away, only about half remains. Could this have an effect on drag? I can feel the prop cavitating when powering on tight corners, lots of 'slip' feel.

 

[rustykyle]

Re: Force 85 HP- 26 MPH :S

switch the cdi boxs around keep track of what wires your switching though and the switch the black-black and black-gray wire harness around they run through the top and middle carbs.

 

[Challenger84]

Re: Force 85 HP- 26 MPH :S

Good Luck!
I just fixed my 16' open bow witha 70hp Johnson.
I can get her to go 42mph now!
Before I had a down cylinder due to fuel and was getting only 15mph @ WOT.
I adjusted the carbs and cleaned the fuel filter.
Try it.
Hope that helps

 

[Big_C]

Re: Force 85 HP- 26 MPH :S

How did you fix it, and how did you determine what to adjust?