This is a bit of a long read, but I tried to include everything I could think of.
Normally I take the boat into a mechanic, however I entered a fishing tournament which is this Saturday (June 15th). I just got the boat/motor back from a mechanic who replaced a bad impeller/pump on Monday June 10th. The water pump works flawlessly now, however I believe I was running the engine with a bad impeller for an extended length of time.
Ok so the problem is a fairly common one, and after going through a lot of threads on here and trying a few different things I have a few questions so that maybe I can figure the problem out tomorrow and still fish the tourney on Saturday.
Engine runs fine on muffs (never ran it more than 60 seconds though), however under load (in water), it barely maintains an idle, but it can maintain it. However anything more stalls the engine. Short of taking apart the carbs and rebuilding them (not so confident I could do it in the given amount of time) what are some ideas?
I had the mechanic check the compression when the water pump was replaced, he said the compression was good, although he didn't give numbers. I also took the boat back to him today, and he checked the spark plugs and they were soaked with unburnt oil and pretty black, though I wouldn't go so far as to say they were fouled. He changed them out for fresh ones and I took the boat back down to the water and the problem was still there. Noticed my trim tab was missing, but was told that it wouldn't cause my problem.
So far with it back in the driveway I called most of the local shops and the earliest any one can look at it is Monday. So I began to tinker a bit. The carbs seem like they are in sync. Choke is working (side note: choked the engine as I gave it throttle under load and that killed the engine even faster). I took off the cover of the air intake and thought it was very odd there wasn't any sort of filter, I feel like there should most definitely be an air filter. Is there no air filter on this engine? I sprayed liberal amounts of sea foam into all 3 carbs with the throttle open, and closed, ran it on the muffs for a minute or so and didn't notice any difference. I was contemplating pulling the plugs and fogging the cylinders as well?
Also went from the fuel tanks (new last year), fuel line (new last year), the bulb, to the fuel filter. All appeared to be in good condition and not pulling any air. Filter looked brand new (may have been replaced in March when I took it in for de-winterizing/tune up). I've tried fresh fuel twice, but used the same oil (Sierra brand), mechanic recommended XD50 but with 18 gallons of fuel in the tanks I'm having a hard time believing its just the oil causing the problem. I was also told that I could fill up my car with the mix without problems, but that doesn't sound good and almost sounds like a way to watch my car blow up or something lol. If any one can confirm that its not harmful to my mini van I'll change the fuel/oil again tomorrow.
I also read that the linkage that operates the carbs has to "hit it just right" when it activates, I assume this is the curved metal plate that links everything together and has a position labeled "start" on it. The nut holding that plate was slightly loose and my first instinct was to tighten it but stopped at hand tight just in case it shouldn't be torqued too much. How can you tell if its activating the carbs at the right time? Mechanic also suggested adjusting the idling screw which is the lower of the 2 adjustment screws (according to him). My question is which direction adjusts the idle up/down? Clockwise,counter clockwise? Also there is another adjustment screw above it, what is that screws function?
I plan to do another check of the boat side fuel system, possibly drain and refill with fresh mix, check the spark on all the cylinders, also contemplated pulling off spark wires to see if I had a dead cylinder (wouldn't the compression check have shown a cylinder down?), contemplated fogging all the cylinders with sea foam, and lastly playing with the idle screw/linkages in the morning and then taking it back in the water and see if the problem is resolved or not before I officially accept defeat.
Anyone who managed to read all that, I applaud you, any one who helps me, I salute you!
Normally I take the boat into a mechanic, however I entered a fishing tournament which is this Saturday (June 15th). I just got the boat/motor back from a mechanic who replaced a bad impeller/pump on Monday June 10th. The water pump works flawlessly now, however I believe I was running the engine with a bad impeller for an extended length of time.
Ok so the problem is a fairly common one, and after going through a lot of threads on here and trying a few different things I have a few questions so that maybe I can figure the problem out tomorrow and still fish the tourney on Saturday.
Engine runs fine on muffs (never ran it more than 60 seconds though), however under load (in water), it barely maintains an idle, but it can maintain it. However anything more stalls the engine. Short of taking apart the carbs and rebuilding them (not so confident I could do it in the given amount of time) what are some ideas?
I had the mechanic check the compression when the water pump was replaced, he said the compression was good, although he didn't give numbers. I also took the boat back to him today, and he checked the spark plugs and they were soaked with unburnt oil and pretty black, though I wouldn't go so far as to say they were fouled. He changed them out for fresh ones and I took the boat back down to the water and the problem was still there. Noticed my trim tab was missing, but was told that it wouldn't cause my problem.
So far with it back in the driveway I called most of the local shops and the earliest any one can look at it is Monday. So I began to tinker a bit. The carbs seem like they are in sync. Choke is working (side note: choked the engine as I gave it throttle under load and that killed the engine even faster). I took off the cover of the air intake and thought it was very odd there wasn't any sort of filter, I feel like there should most definitely be an air filter. Is there no air filter on this engine? I sprayed liberal amounts of sea foam into all 3 carbs with the throttle open, and closed, ran it on the muffs for a minute or so and didn't notice any difference. I was contemplating pulling the plugs and fogging the cylinders as well?
Also went from the fuel tanks (new last year), fuel line (new last year), the bulb, to the fuel filter. All appeared to be in good condition and not pulling any air. Filter looked brand new (may have been replaced in March when I took it in for de-winterizing/tune up). I've tried fresh fuel twice, but used the same oil (Sierra brand), mechanic recommended XD50 but with 18 gallons of fuel in the tanks I'm having a hard time believing its just the oil causing the problem. I was also told that I could fill up my car with the mix without problems, but that doesn't sound good and almost sounds like a way to watch my car blow up or something lol. If any one can confirm that its not harmful to my mini van I'll change the fuel/oil again tomorrow.
I also read that the linkage that operates the carbs has to "hit it just right" when it activates, I assume this is the curved metal plate that links everything together and has a position labeled "start" on it. The nut holding that plate was slightly loose and my first instinct was to tighten it but stopped at hand tight just in case it shouldn't be torqued too much. How can you tell if its activating the carbs at the right time? Mechanic also suggested adjusting the idling screw which is the lower of the 2 adjustment screws (according to him). My question is which direction adjusts the idle up/down? Clockwise,counter clockwise? Also there is another adjustment screw above it, what is that screws function?
I plan to do another check of the boat side fuel system, possibly drain and refill with fresh mix, check the spark on all the cylinders, also contemplated pulling off spark wires to see if I had a dead cylinder (wouldn't the compression check have shown a cylinder down?), contemplated fogging all the cylinders with sea foam, and lastly playing with the idle screw/linkages in the morning and then taking it back in the water and see if the problem is resolved or not before I officially accept defeat.
Anyone who managed to read all that, I applaud you, any one who helps me, I salute you!
