1989 50HP Force wont plane out

[Medic61]

Hello all-
New to the forum. Recently obtained a 1989 Bayliner with a 50 HP Force OB (first boat ever). I know it's not the "best" motor, but it's what I got. From what i can gather, had not been run in about 4 years...sat in a driveway exposed to the elements. Had to replace throttle cable. Ran it in idle in driveway with prop in garbage can. Ran rough at first, changed plugs, ran carb cleaner additive in fuel. Got it running smoothly in idle. Brought it out on water the other day and could not get it up on plane. Sounded great, but about 10 MPH is all it would do. The spedo tube is broken, so can't get an accurate speed. Brought home, took apart and cleaned carb (very gummed up). Brought back out and still would not plane. RPMs sound appropriate, but speed does not increase. Took apart lower unit and checked shafts, all appeared fine. Prop would not turn in gear, spun fine in neutral. Checked compression tonight, 120psi both cylinders. Last thing friend suggested to test was spark heat (magneto?). Blue good; red / orange bad. Any thing else anyone can suggest? Kids really want to go fast (er).

 

[jerryjerry05]

Re: 1989 50HP Force wont plane out

Gotta check the spark.
Check the fuel pump diaphram.
outboard ignition .com
cdi troubleshooting outboards .com
Both have test procedures for your motor.
No magneto.You should have,Prestolite CDI ignition.

 

[Medic61]

Re: 1989 50HP Force wont plane out

Thanks for the input. Will continue to attempt to track it down. After asking some others, would a small variation in the prop prevent it from getting up on plane? The prop currently does not look obviously bent, but is does have some digs and dings. Also, am not sure if they gave me the right plugs from NAPA; had to be ordered and I assumed they were right, but neglected to actually see if the numbers matched. I know...need to get a manual for the motor! Thanks again.

 

[Jiggz]

Re: 1989 50HP Force wont plane out

If the RPM seems about right, the only reason it could not be going on plane is if the trim is too high thus the boat will continue to "plow" instead of planing. The other thing could be the prop pitch. The standard for your engine is a 10 3/8" - 10P all the way to 10 3/8"-13 1/2P.

 

[wickware]

Re: 1989 50HP Force wont plane out

If it set out w/o a good tarp, could it be water-logged? ?Too Heavy? under the floor if the design will allow?

 

[Medic61]

Re: 1989 50HP Force wont plane out

 

[Medic61]

Re: 1989 50HP Force wont plane out

Jiggz-
You lost me at Hello... The photo is of the trim positions available. I have no power trim. On the water we tried several of the positions without change. One actually made the motor clunk and stall. Would not throttle again until we moved the pin back.

Wickware-
The floor was in fact ruined. 90% of the interior was ripped out and replaced with marine plywood. The only original areas left is the float foam in the bow area. There probably was about 150 pounds of wet wood / fiberglass...all gone. It is also a 14 foot fiberglass bayliner. I understand the reasoning, but even if there was 200 pounds of extra drag, shouldn't a 50hp move the thing?

I am suspect of the plugs now. I replaced the plugs that it got it with with RL82C Champions from NAPA. I am reading perhaps the correct may be Champion UL18V? Also listed on the forum is L-82-C plugs (aren't they the same I replaced with?)

I do really appreciate any input...pulling the little hair I have left out!

 

[Medic61]

Re: 1989 50HP Force wont plane out

Jiggz-
I got you now. The propeller pitch I currently have on the boat is 11 1/2. The boat does not have a tachometer, so I can't find my WOT RPM. I suppose you'd suggest installing a tachometer?

 

[Jiggz]

Re: 1989 50HP Force wont plane out

You mentioned this is your first boat ever so when you mentioned the WOT RPM seems about right is not exactly the same as coming from someone who has experienced with the same engine. Anyways, the original spark plug is L82C and these are the recommended replacement. As for the RPM indicator, you can just buy a tinytach which will at least give you an RPM indication.

http://www.sparkplug-crossreference.com/convert/CHAMP_PN/L82C

 

[Medic61]

Re: 1989 50HP Force wont plane out

I don't dispute that. I knew I wasn't sure about what I was listening for. So the second time I took my more boating experienced neighbor with me. He also runs a 50HP, but not a Force. We could hear the RPM increase with increased throttle, but the boat would not increase speed. Thank you for the spark plug link. I will get a tach, as it will most likely assist in determining the problem.

 

[Medic61]

Re: 1989 50HP Force wont plane out

Discovered #1 coil producing minimal, erratic spark when compared to coil #2 (strong, clean spark). Tried different plugs to rule out the plugs themselves. Attribute to horse power problems? Searching on line for the coil pack currently.

 

[emoney]

Re: 1989 50HP Force wont plane out

Coil could very well be your issue. Putting the back pressure on in the water is when those issues come to light. Never assume "running fine in the driveway" equates to running fine int he water because they're two different animals. Nothing wrong with that Force. Most of those were leftover Chrysler 50's and IMHO those were dang good little motor. I still some old Chrysler parts laying around from my last one. You should definitely be getting closer to 30mph in that boat with that motor. May not hit 30 depending on load, but at least in the 20s.

 

[Medic61]

Re: 1989 50HP Force wont plane out

Any idea which the correct coil is? Found on that looks awful like it, and another that looks nothing like it, but is listed as the new replacement.
http://www.iboats.com/mall/partfind...&gd_poid=334768&gd_row=7&session_id=958525114

http://www.ebay.com/itm/F684475-1-3...ear&hash=item3cc5f3b2c0&vxp=mtr#ht_1689wt_998

Thanks for your help!

 

[Jiggz]

Re: 1989 50HP Force wont plane out

Here's link for the original parts list and their part numbers: If this is not the right model just go back and select the one for your engine. sometimes the problem is not in the coil or the CD but in the trigger. When you go high speed the trigger seating on a trigger advance place moves and sometimes a wire or two will rub off causing misfires. The problem is to check this you need to remove the fly wheel.

http://www.crowleymarine.com/mercury-outboard/parts/1281_30.cfm

 

[jerryjerry05]

Re: 1989 50HP Force wont plane out

Another thing,If the exhaust snout is missing it won't accelerate right.

 

[Medic61]

Re: 1989 50HP Force wont plane out

The exhaust snout is on. Pulled both coils and the CD unit off last night. Did find some crushed wires and replaced them. The number one coil is still producing a weak spark. If I change to the other coil, same problem. Position #2 off the CD produces a good spark (both coils) I am going to try and trace it back up to the trigger, as suggested above. Anything I should be aware of when pulling off fly wheel? I'm assuming I will be able to trace the wires up to the trigger from the CD unit.

 

[Medic61]

Re: 1989 50HP Force wont plane out



Thank you all for your assistance and trouble shooting. Changed out the CDM and it is running like a champ! Daddy and kids very happy!

 

[stevez9one6]

I see this is old post but I'm hoping to find some help. I have a 90bayliner with a 50force 1990 and I'm having the same issue. What is cdm? I redid the carb gaskets and fuel lines. and it fires up first click everytime. Sounds great at idle to. But on the water it tops at about 11 (gps app) . Looking for some direction. Thanks and hope this reaches !

 

[The Force power]

I see this is old post but I'm hoping to find some help. I have a 90bayliner with a 50force 1990 and I'm having the same issue. What is cdm? I redid the carb gaskets and fuel lines. and it fires up first click everytime. Sounds great at idle to. But on the water it tops at about 11 (gps app) . Looking for some direction. Thanks and hope this reaches !

Welcome to IBoats :welcome:

Start your own (new) post but in the mean time.. check if you have spark on both Cylinders & check the compression on both Cylinders
Inspect your fuel-pump
What are the RPM's at WOT?
How heavy is your Boat?
Do you have the right Prop?

post your results