04/22/02 - I have run a compression test. See post below.I have a problem I know you guys can answer. Trent was a saint in helping me get this thing running again. It starts and idles like a champ. However, I was out about a week ago and stopped to fish. Everything was fine. Left the fishing hole and the darn thing didn't have enough power to plane out. (It's not because of I added weight by stopping at that fishing hole!)It has been the same ever since. With two people in the boat, one guy has to shift his weight to the bow in order to plane the thing out. Once planed out, and we run for a while, and then back down to idle, the engine will flood and will eventually stall out. I also have discovered that removing the wire from the plug on the top two cylinders does relatively little to idle (it does something, just not much). Removing the wire from the plugs on the other four cylinders stalls it out or it runs very rough. There is good spark to the top two cylinders, just as good as the other four, I'd say. The primer bulb seems to be working fine. It will firm up and stay that way. Now, am I looking at two different problems... loss of power and flooding out separately or are the two related. Any help is much appreciated. Thanks!.
Hi there mate,before spending any money in repairs,make sure you have'nt got any kinks in the fuel hoses,cause that will can give you that problem by starving the motor of fuel.I had a similar problem on mine and all it was a kink in one of the hoses.After I took the kink out all was well.Good luck.
I pulled her apart yesterday afternoon (with the help of my new shop manual!) and I'll add the following. In both the carbs (bowls and jets) and the fuel pump I have found a few drops of water. don't know how it could have gotten there, but how much water would need to be in the fuel to cause this bogging down problem? The fuel pump looks perfect, as it was rebuilt recently... filter screens are clear, gaskets are sound. The vent line to the fuel tank is clear, and the bulb and fuel line are fine. However, squeezing the bulb enough can make a pretty good amount of fuel leak out of the top carb. Carbs all have new gaskets, and look good inside. It seems though that the needle does not always move on the top carb. I cleaned it up as best I could, seems to be working now. Havent had time to look at the bottom two yet. Plugs in cylinders 1-2-3-4 were oily, and had burnt black residue on the electrode. Cylinders 5-6 (which are running together off the bottom of the three carbs) had perfect plugs. Does this sound like a carb problem on 1-2-3-4 or compression problem? Thanks sooooo much!!
Any water is too much. Water seperator filter kits are cheap these days ($25 or so), and are fairly easy to install.I would still check the compression, since you are this far into the engine.
Okay, I've got her all back together and running again. It idles, except the top two cylinders are dead. I haven't gotten a compression gauge yet, but the cylinders easily blow my finger out of the hole when cranking. It's a good thing I am 6'8"... I can do the redneck compression test without an assistant! I'll get the gauge this weekend and check it, but I think it's okay. The carb that supplies these two cylinders is leaking fuel out of the air vent when idling (this is a 1983 Mariner with the side bowl carb). I am assuming it a seat problem in the bowl. I have ordered a carb kit for it. It seems though that the cylinders should still be getting fuel regardless of this leak, right? (probably too much fuel) Are my two dead cylinders a result of this carb? I think it must be a reed problem if things don't improve with the carb kit, and the compression check results are satisfactory. Am I on the right track. I have definitely learned a ton! I have decent spark to all 6 cylinders. thanks so much for everyone's help. Sean
Hi everyone. I finally got around to running a compression test, and the numbers were fantastic! I hope I did this right. It was a cold compression test, I removed all spark plugs and cranked the engine over several times for each piston. The numbers range from 143 - 148 across all 6 pistons! I am shocked at these numbers, but I bought a good compression gauge, and followed the instructions on this board to a t. So now, with these numbers, I just don't understand why my top two cylinders arent' doing much. After further research, the spark does not seem to be as strong on the top three cylinders as the bottom three. The bottom 3 give a good 1/2 inch gap to the block, the top three don't fare as well. Thanks! Sean
90 HP Mariner... Compression numbers
Linear Mode
