97 force 40hp question

[djj.simon@gmail.com]

Just got the boat [first one ever], have clymer manual, ran some preliminary checks.<br />With ears on, starts/runs fine-water out of prop/exaust warm, engine not too hot, engages in both gears. Plugs a little oily, not wet looking after running, but slightly milky after a day of sitting.<br /><br />In the water it starts, but dies, only runs [eventually stalls] with full throttle in neutral.<br />Smoke from cowling, some water in lower cowling [splashing?]<br /><br />Lurking through the posts shows that possible exaust gasket failure forcing exaust into the cowling instead of the pressure of submurged prop/exaust is likely?? [no air to burn fuel?]? another possibility is the lower unit is suffering a sheared bolt on the connection to the middle of the outboard...is it possible that exaust is going into the shaft/water pump side? would that matter? <br />Compression is ~122 on each cylinder... book has no listing for this series/year, but for a different year range seems to indicate the difference should be less than 15psi, but not what the pressure should be.<br /><br />I have never messed with a 2 cycle/water cooled engine [not afraid yet...]<br /><br />Any suggestions?<br />Thanks, Dave

 

[roscoe]

Re: 97 force 40hp question

Has motor run properly at all since you have had it?<br /><br />Do you have the vent on the gas tank opened up, so air can replace the gas that is being removed by the fuel pump?<br /><br />What is the condition of the fuel line pump bulb? flat?<br />Will it pump up firm?<br />Do you pump it up before starting the motor?<br /><br />Compression looks adequate.<br />Run the engine with the top cowling removed to see if the exhaust is snuffing out the motor.

 

[djj.simon@gmail.com]

Re: 97 force 40hp question

Its only been run by me on ears, "successfully". It evidently ran fine before...before I bought it that is.. <br />The first time in the water I got the symptoms I described. I never did anything to the cap on the tank..I guess I never knew to do anything because it ran out of water fine without messing with that. Regarding the bulb, it is not deflated, and is hard when the engine is running. It only needed the bulb primed once to start it on ears several times..it seems to hold its pressure... <br /><br />I will try all of those things this weekend and update the forum. <br /><br />Thanks for your time...<br />Dave

 

[djj.simon@gmail.com]

Re: 97 force 40hp question

Well, I was running with the fuel primed, and the cap vent loosened. I went over the engine wiring and made sure the ends were clean, and no corrosion. I replaced both spark plugs. Replaced all of the fuel with fresh, and added a fuel filter/water seperator [it never had one before I bought it] after flushing all of the old fuel out. I removed and checked the carb.. It was clean and the float/jets etc seems to be fine. I also checked the pump/thermostat and they seemed fine.<br />I also got a barrell so that I could test it in water, not with ears. with the cowling on and off it starts immediately. With the cowling off, after it starts there is a large amount of smoke/exaust which clears up in a few seconds. It runs decent, but not well. If I put the cowling back on, it starts to die right away, and eventually stalls in 15-20 seconds.<br /><br />Short of changing the fuel-air mixer to 1.5 or 1.25 turns [I have not messed with it yet] and pulling spark plug wires and testing for spark [it seems to run on both, and I need nylon pliers] ..I dont know what to do.. I purchased but did not install new adapter plate and exaust gaskets..<br /><br />Any other suggestions?<br />The long delay in posting to re-posting is due to other stuff getting in the way of fun..<br /><br />Thanks in advance.<br /><br />Dave

 

[roscoe]

Re: 97 force 40hp question

The stalling once you put the cowl on is a definite indicator of exhaust gas leak. I'm a bit surprised it happens in under a minute, but I guess that is an indicator of how bad it is.<br /><br />Nylon pliers would be nice, wouldn't they?<br /><br />Time to dive in and replace those gaskets.<br /><br />Before you start, double check all the wiring. Just to make sure the cowl isn't pinching a wire somewhere, cauing it to ground out and kill the motor.<br /><br />Keep us posted.

 

[djj.simon@gmail.com]

Re: 97 force 40hp question

Well, I studied the thing while running and there was exaust and water coming in around the bottom of the engine. Both exaust gaskets and both adapter plate gaskets are getting replaced. 3 of the four were bad. <br /><br />While the power head is off, im also replacing the driveshaft housing gasket, and the head gasket... figure I'll get em all while its out. any tricks on either? <br />Seems like ill need to remove a section of the upper plate/driveshaft that acts like a motor mount..and the cylinder place/top does not seem to have a gasket...weird. I got all new bolts for the exaust/head because the exaust ones were corroded, for a buck a piece its worth it to stave off new corrosion. I am running in salt water after all. Any further advice?<br /><br />I'll weigh in when finished with results.<br /><br />Thanks<br />Dave

 

[djj.simon@gmail.com]

Re: 97 force 40hp question

Well, All adapter plate gaskets are replaced [three]. I chose not to replace the head gaskets, they were fine. Several siezed bolts and a few drills and taps later, it seems to run fine. There is no exaust leaking, and no water in the cowling. I have had it on the water twice and it seems to be fine at wot. <br />Is it normal for a stutter once in a while?<br />What is a good estimate of fuel economy? [gallons/hour @ wot]<br /><br />Thanks for the help!<br /><br />Dave