Goes off or Power drops at full Throttle

[miqbal]

Hi! Needless to say I purchased the pain Force50 about a yr ago and it is 1985. I have never been able to drive the boat at the full throttle. I get less than 1/2 of the power. Most often it goes off or turns very slow as I shift it to the full throttle. I talked to few mechanics but did not find anyone to guess anything except saying FORCE IS BAD. I have also paid about $100 to Bayliner dealer just to look at my UGLY motor, giving a pretty smile and say do not know without opening that crap. <br />Anyway, I tested with my 2 props and both of them are in good condition with hub and pitch, replaced the fuel and spark plugs, but did not improve. My bottom spark plug always get greasy after running about 30 mins and always release lots of smokes. <br /><br />I then finally opened the engine, found the head gasket is bad and God! it has tons of stains (very thick) around the body and in front of the lower pistons. Now I know why my bottom spark Plug used to get bad.<br /><br />Questions: <br />1)Anyone can guess if this was the reason of my problem? <br />2)How do I clean all these stains? I also found my fuel filter(I think it is called the Fuel filter) made up with metal and has two net of which one of them were clogged with stains. The fuel line form the tank is not connected with this filter. The actual fuel line is connected with another rubber filter on which it says "Filter".<br />3)Any idea how to get out my lower piston.<br />4) through the wholes I saw an empty space under the lower piston where it has the 15 yrs of stains deposit - how do I clean those? <br /><br />Any help/comment would be highly appreciated.

 

[12Footer]

Re: Goes off or Power drops at full Throttle

How may pounds compression did each cylinder have before you removed the head?<br /><br />The "Stains" you refer to would be carbon, if it is black,tarry-looking stuff.<br />All 2 cycle outboards, but esspecialy Force outboards,need frequent decarbing, or you will destroy the engine...Garaunteed.<br /><br />The round gizmo with the screw in the middle that reads" FILTER" on the starboard side, is the fuel pump.<br />Underneath will be a metal screen. This filter is part of the fuel pump,and is the last strainer before fuel from the tank goes into the pump.<br />I wish I had your motor for 8 hours.You wouldn't recognise it on the water. It's sad that some mechanics try to sell new motors to people who just want to get thier fuel pump and carb rebuilt.<br />But, after 15yeas of running it without decarbing, all bets are off.<br />But I'm curious as to why you need to pull the pistons out. Are the sleaves scored,or low compression?

 

[miqbal]

Re: Goes off or Power drops at full Throttle

Thanks bunch for your time captain. I did guess that there might not be any hope for this motor. I opened the head without checking the comp and wanted to open the lower piston to clean the front side(where the spark heats) with the break parts cleaner. <br />As far as I do not have any hope , do you recommend if I should start removing the carbons cautiously with a flat screw driver and using the break parts cleaner? I am not going to touch anywhere in the pistons but just from the surface of the engine under the head. I believe cleaning the surface is not a challenge but it would be a real critical job if not impossible to clean the big space just under the lower piston. Also, while cleaning the surface, some long slices of carbon might fall down to the exhaust compartment (middle section of the motor) and I guess those have to be removed by opening the middle part. Can you pls tell me what risk I might face opening the middle part or if it ever be wroth opening it? Thanks again.

 

[DJ]

Re: Goes off or Power drops at full Throttle

Do not use carb. cleaner. Are the cylinder walls scored? If not, put the head back on and try to start it. Once you have it running you'll need to decarb it.<br /><br /><br />If the cylinders are scored, it's probably not worth saving.<br /><br /><br />I would also rebuld the carburetor and replace the water pump..

 

[12Footer]

Re: Goes off or Power drops at full Throttle

No need to open the middle. This end of the exaust is mixed with water from the engine's cooling system, and the cmination of the two should keep it open.<br />As Djohns stated, don't try to decarb it when it is half way appart. If the ports are totally cloged, just remove enoug to open them,and make sur yu don't loose a chunks if you canhelp it. Then re-assemble the head. Rebuild the fuel pump and carb. Run a compression test. You will need the manual for all te tourqe specs and such. It will pay for itself many times over.<br />Once the engine is running,decarb the engine using "decarb Cleaner". Follow the directios on the can.<br />After decarbing, recheck the compression. It should improve.

 

[MURX]

Re: Goes off or Power drops at full Throttle

My main pet peive is if an outboard motor is not perfoming the way it should I.E. it won't make power as noted here, why on earth do people go ahead and run em' most common problem is a clogged jet, or stuck needle valve, or float problem. <br /><br />The downside if you run an outboard with one or more carbs plugged than you are not only starving your engine of fuel you're starving your cylinders of lubrication, half of the outboards that need to be rebuilt could have been saved with a simple trip to the dealer for carb rebuilds and component tests, repairs that are very affordable compared to rebuilt powerheads.<br /><br /> In my not so humble opinion sometimes it pays to see a professional, these guys live and breathe this stuff day in and day out.<br /><br /> Every city accross the nation has a honest outboard mechanic seek them out and use them! in the long run it will save you money, trust me

 

[miqbal]

Re: Goes off or Power drops at full Throttle

I appreciate and thank all of you 12 Footer captain, DJONES19 and MURX for sharing. I liked all of your opinion no matter how it sounds and took them all as advise. I love this site and love all of you who participate in helping people, learn and share expertise. I have learned a lot from you in 2 days and am very grateful.<br /><br />Murx, you are right but hope u would understand I already paid a mechanic $27 to ordered my little external exhaust cover and was told that would fix the problem. It did not make any difference. Then paid $69 for starting and checking my engine and $69 told me will have to open the engine. He was an absolute rascal. I heard these people keeps changing until they replace everything but the boat, what I well could do it myself . Well, I also wanted to do it myself to learn . If I can't, I must take it to them. I do not think my motor worth of $300 then why pay mechanic more than that .<br /><br />Anyway, just wanted to share what I am going to do and have the last question at the bottom. HOPE THIS MIGHT HELP OTHERS AS WELL. I have ordered a book, and will order Carb repair kit, gasket kits, fuel pump, water pump and/or impeller. I will rebuild the carb, replace the fuel pump, and use the deacrb cleaner.<br /><br />By the way, I cleaned the head last night and opened the both left and right compartment of the engine (not sure what are they are called). The left side (the electric circuit board is attached on it) was the worse than any others. Had tons of carbon deposits inside the metal cover and around the walls by the lower piston. This cover also has a fuel line and found the hole inside the cover almost clogged with carbons. I cleaned up all those. The right side had two thick metal covers and a square size 6" long "FUEL FILTER - I believe". one of the cover has the round shape black "FUEL PUMP" with a screw at the center. Both of them looked clean and good except the fuel filter. It had two screens and one of them was totally clogged. Both of my pistons also looked good. <br /><br />Now I wanted to open my Lower Unit. Opened the 4 nuts and it came off about an inch. Now it is hanging and can't bring it down. I read this in other's discussion about loosing the shifting nuts. Could you please tell me what/Where it refers to for this FORCE motor? <br /><br />Once again thanks for all the helps and sharing your expertise.

 

[12Footer]

Re: Goes off or Power drops at full Throttle

The shift linkage on your engine comes out of the leg, just above the lower unit,on the starboard side. There, you will find where the two rods are put together. The shafts are threaded together with a 2"long nut,and two regular sized lock nuts. be sure to mark these two shafts so that you can put the halves back in the same place. If you don't get this right, you will play hail getting the engine to shift properly afterwards.<br />How did the lube look in the lower unit?