92 40hp Force, only runs when trimmed up and more!

[scorp76]

Hello to all here, I recently joined the club buying a used boat with a 1992 40hp force outboard. I am real pleased with the engine but think there may be a few adjustments to be made. A quick history on the boat... one owner, well taken care of and always kept under cover but it had set up for 2 years without use before my buying it. Motor is electric start, and power trim.


First off I changed the impeller for the water pump as it was overheating at idle. Now I have a few new problems.

1.) engine will only start and idle if trimmed all the way up. (carb issues I am thinking) With cowel off I can see fuel stream out of a port on the top of the carb when the engine is running.

2.) when engine is in neutral the prop still turns although not usually any more than what you could stop with your hand. I question this as I know it did not do this before I changed the impeller so I am thinking I have something amiss with the shift rod.

3.) last but not least, when testing the new impeller, I had what I could only describe as a "runaway throttle". with the engine out of gear the throttle raced and would not come back down, with the engine now running at full throttle I tried to turn the key off, this did not work. Then pulled the kill tab, no luck! I had to work it into gear and let the boat push itself against the boat trailer until it bogged itself down and died. This only happened once but was enough to scare the heck out of me.


Any and all help will be greatly appreciated. This is my first boat but I am very mechanically inclined and do all of my small engine and vehicle repair.

Thanks in advance,

Brian

 

[CapCramer]

Re: 92 40hp Force, only runs when trimmed up and more!

Sounds like a "fish" story to me. But I have been wrong before!

 

[steven4141]

Re: 92 40hp Force, only runs when trimmed up and more!

Your float or float needle, (in the bowl under your carb) is stuck open. fuel is not shutting off when the bowl is full. Thats the over flow where you see fuel running out of. Disassemble and clean the carb, any spray carb cleaner will work, I prefer alcohol based degreaser, just dont get it on the float (remove it and the float needle by carefully sliding the little pin out first) it'll eat it ( the float and rubber neddle seat ) up like gas in a styrofoam cup Spray all the ports untill they are clear then reassemble. Test (in water, trashcan or what ever) could have been just gunked up from sitting, if your still overflowing, bend the little tab that the needle rides on up VERY SLIGHTLY !! so that the needle closes quicker. there's a distance between the bottom of the carb and the top of the float to pre set to but I don't know it right off hand maybe Frank or someone else may know it. any way you you can bend it and test then bend a little more untill it quits overflowing it's just more time consuming. just remember very slight bends go a long way. Hope I explained that in an understandable way, It;s really easier to do than it is for me to explain, and quicker than I can type it

 

[steven4141]

Re: 92 40hp Force, only runs when trimmed up and more!

One more thing search the forums here for the procedure to set the rich/ lean mixture screw, too lean will destroy an outboard in seconds !! In short run the screw all the way in but don't force it, once it stops. back it out 2 full turns, start engine and Immediately start backing it out untill engine sputters then turn mixture screw in only untill engine smooths out. Please read as many other post on this as needed to fully understand and then read 'em again I'll say it again too lean and you'll destroy your engine. I'm at this moment putting one back together that I bout that was run slightly lean. I got it cheap but not as cheap as I thought new head gasket, rebore, new rings, probably new pistons and wrist pins, $300 -$500 more than I thought and that,s with me doing all the work including the machining. Too Lean = bad news

 

[Frank Acampora]

Re: 92 40hp Force, only runs when trimmed up and more!

First, if I understand you correctly, WHY IN THE HELL ARE YOU STICKING YOUR HAND INTO A RUNNING PROP? Sure it may be in neutral but what if?
Murphy always strikes when you least expect him.

Yes, it is normal for the prop to turn a bit while the engine is running in neutral out of the water. Probably in the water too, but I never looked.

Second, the needles on the carbs are sticking or the float level is too high, causing the carb to flood. Trimming or tilting the engine lets excess gas dribble out the front and the engine will start and run. Sitting level, the gas goes into the engine and the too rich mixture will not burn.

Lastly, If the shift linkage is not properly adjusted or if the components under the flywheel (trigger ring) are dragging a bit, they can sometimes overpower the return on the throttle.

The engine not stopping sounds like the urban myth of runaway automobiles, however, if the circumstances of broken wires or poor connections on the ignition and kill switch was to happen (unlikely for both in my opinion, but stranger things have happened) then the engine would continue to run.

BTW: It has been proven that with the runaway autos, they did run away, but because of inadvertant operator error. It was determined that those models had gas and brake pedals just slightly different than spacing on most other cars leading to drivers (rarely) inadvertantly hitting the gas pedal when they went for the brake, mostly during a stressful situation requiring quick actions.

 

[scorp76]

Re: 92 40hp Force, only runs when trimmed up and more!

Thanks for the replies...


While waiting to hear back on this post I went ahead and took down the carb and cleaned it, runs good now but still need to set the idle screw just to make sure its not too lean.

I finally got the linkage set just right so that the prop doesn't turn while in neutral. BTW, I put a boat paddle by the prop first to see how fast it was and stopped the prop before turning with my hand. However the problem did get worse before it got better, the prop started turning enough that it would move the boat while in neutral. I read a few other posts on here about shift linkage and followed some directions on getting this set, it got me close but one out on the water the prop stopped moving the boat in forward, made another final adjustment and bam... got it just right. I also read something here about a dog or dogging gear that may wear out and not allow your motor to go into neutral???

With regards to the "runaway throttle" I think my throttle lever assembly is worn, I have a new one but can not figure out how to shorten the shaft at the end of the shift cables, one them is a few inches too long and will not connect to the shift arms in the motor. Any suggestions anyone?


Thanks for all of your help...