Possible fuel shortage....

[kingbingy]

Afternoon all. This Forum is great...<br /><br />I have an 88 125hp force motor on a 18 bayliner. I did a complete tune up, including water pump and Thermo, Changes spark plugs. IT had a over heating problem, but after reading the boards here, I was able to figure out that the thermo was the cause.<br /><br />After that I dropped the boat in the water and tried to get going when it wouldn't stay started. I noticed that gas was spewing out of the carbs. At that point I took the boat back home and rebuild carbs.<br /><br />I finally rebuild carbs and dropped boat back in the water and it seems to run good on idle. When putting boat in drive, it would want to shut off. so I adjusted carb to increase idle. Seem to help a little. No more fuel spilling after cleaning out carb. When giving it the goose it feels that it is not going anywhere. But what I notice is that it feels that it was to turn off on me after a short period but after pumping bulb the engine starts to work ok. So I took the boat back home.<br /><br />Yes, I have a set of bunny ears, but it seem to run good at home. <br /><br />I took the fuel pump apart and that seem to be ok. I also noticed after taking out all spark plugs that sparks 2 and 4 was heavily gummed up with oil. Where 1 and 3 seems to be ok. At this point I am not sure if I am having a compression problem, After reading a few of the boards now, I will check tonight if I am getting sparks from each wire. I will also try and get a compression tester to confirm that all cyl. are moving. <br /><br />I think that could be the reason why my boat is moving like a snail. But I am not sure what pumping the bulb would prevent the boat from stalling. Even after pumping the boat sometimes stalls.<br /><br />Any thoughts would be great.

 

[roscoe]

Re: Possible fuel shortage....

It could very well be a low compression problem.<br />It runs ok at home on the earmuffs, because there is no backpressure on the exhaust when using the muffs. When the motor is in the water, it cannot overcome the back pressure.<br /><br />The fuel pump also operates on compression pressure from the crankcase, which explains your pumping the primer bulb situation.<br /><br />Fouled plugs also from incoplete combustion caused by low compression. But I would bet that the clean plugs are the bad (low compression cylinders) as they may be getting steam cleaned if water is leaking into the cylinders from a blown gasket.<br /><br />Doing a thorough DECARB of the engine may free up a stuck piston ring, and give you some more compression.<br /><br />Low compression could also be a result of the overheating problem you mentioned, it may have blown the head gasket when it overheated.<br /><br /> Click for info on decarbing. <br /><br />So, check compression, then, if compression is low, examine the head and gasket.

 

[punkyBOATER]

Re: Possible fuel shortage....

Yeah i agree, I pulled a 85 force 125 out of a four year hibernation and when i went to fire it i had the same fuel spitting carb prob. Thats from stuck floats in the carbs. I took my float bowls off right away and there was a layer of oil that had separated from the fuel that was in there when the previous owners had put it away. Pull the float bowl and make sure your floats are moving freely also go to your local outboard motor service center and pick up some power tuner spray. Spray alot in the carbs while the motor is running, almost till the motor stalls out but dont let it stall until u are well over half a can and make sure and do both carbs go from one to another till you feel u have used enough. I used half a can some people use a whole can im not too sure on this but id rather save half a can for next time. This might get your some compression back as well. Definitly a cheep alternative to a top end rebuild. Im not sayng u dont have a bad motor but i like to exhaust all the cheep alternatives before i go tearing into something major. I had almost identical problems as u after pulling my force 125 out of hibernation...had the over heating, did the water pump and thermostat and it fixed it. When you dump that power tuner in u might want to use an old set of plugs cause it might foul out your plugs. When your done spraying half a can or more into the motor switching back and fourth form carb top carb "there shoud be a small hole in the plastic piece that cover the intake side of the carb butterfly to spray through so u dont have to take those off" go ahead and stall out the motor using the spray. Leave it for more then three hours, i left mine in over night and when u fire it up dont do it in your drive way cause it leave a big black mess and lots of smoke. GOODLUCK and i hope you dont have to pull your head.

 

[kingbingy]

Re: Possible fuel shortage....

Well I have some good news and some bad news. The good news that my cylinders has great compression. Each cylinders was pumping at 140 psi. Now for the bad news, I check the juice coming from plug wires and indeed 2 of the 4 cables were not firing. After a few test I was able to determine that numbers 1 and 3 were not firing. So I tested the coils on all seems to be working after swapping wires around. What seems to be the problem is the c-d units. What is weird is that both c-d unit (Which are blue) have what I would call two channels on each unit. But one of the channels on both c-d units are not sending power to the coils. So my question is "Can both one channel just be bad on the c-d units on both? That is too weird for both to be bad. But I see in the book that there is a trigger, does this supply power to the c-d units? If so, could this be the unit with two bad ports (that's what I would call it)?<br /><br />Any ideas would be great. Because I wouldn't want to bad some c-d units (Which are over 200 bucks a piece, which I may need two)when I don't really need them.<br /><br />P.S. I also can't find the serial number for my motor. That is giving me hard times, since I need that to figure out what parts I need to order.