Honda 50 multiple problems

"Hey guys, my first post here

"Hey guys, my first post here with a trouble motor. I did some searching but couldn't find anything along these lines. I've done some testing and here is what I've found.

Okay so a 2001 or 2002 BF50 came to me for diagnosis. The owner (not 1st owner) told me that it runs for 15/20 minutes or so and then the buzzer comes on, loses the green oil pressure light and it dies, will restart but won't run well at all. Basically limps back in.

I don't have a dyno so I can only run it with the hose and earmuffs attached. It seemed to run well except for two things I noticed. A little lumpy running at idle (nothing major) and definately the water tell tale stream isn't as strong as it usually is. When you'd run it at 2500 rpms for a minute and drop down to idle it seemed like the water stream would practically die off.

I pulled the t-stat and found rubber pieces lodged around there. I pulled the water pump open and it didn't look thaat bad, impeller certainly wasn't missing pieces. I went back to the motor and looked more at it and realized that the silicone sealant around the bottom of the cylinder block and crank half was definately not factory. Someone has been in here before.

Okay fine. I install a new Honda t-stat and full w.pump assembly including the lower housing.

Fire it up and while the water stream was a wee bit better it certainly wasn't as potent as what I'm used to seeing and now it would stay steady at least and not weaken after a bit of fast idling. Oh yeah, lots of zebra muscles noted around the water pump but nothing in any of the water jackets I could see, checked behind the exhaust water jacket cover, clean.

Go to lake, it runs perfect for 20 minutes and dies out with no green light and buzzer. Comes back to me. Okay something is fishy. Spend some time thinking about it and the lumpy idle so I do a compression test just for giggles. 175, 75, 175. OOPS!! Big problem. Pull head off and cyl 2 intake valve visually seems bent. Move the cam to close cyl 2 valves put the head combustion chamber up and put some solvent in cyl 2 combust. chamber and its pouring past the valve out the intake runner.

Okay..... hmmmmm. Take oil filter off and cut it open. Tonnes of dark colored shrapnel in between all the pleates. Dig some of it out put it on my stainless tray, wash it dry and it is totally magnetic. My pick up magnet picks it all up.

No heavy scoring in the cylinder walls, only a little bit of polishing on the load bearing sides, tops of pistons are carboned up.

At this point I think I have multiple bogies. Lets say this motor hydro locked and bent valves, or carboned up and bent valves. Why does it run for 20 minutes then lose oil pressure?

Why is the water stream so weak even with a new pump and totally clean unobstructed water jackets. Could there be a crack in the head or the block.

How old is that oil filter, is the shrapnel in there from before? These are the things going through my head and I don't know which direction to go in while spending the least money for the guy.

Thx a bunch in advance if anyone has any suggestions from experience."

"If it's been in storage o

"If it's been in storage or not run for some time, the valve has probably seized in the guide in the open position, then bent on start-up(not uncommon in humid conditions).
Or there's been a previous timing belt problem(incorrectly fitted).
The oil pressure fault is most likely either a faulty oil pressure sender unit, or bearing/oil pump fault."

"How's the #2 cyl big-end

"How's the #2 cyl big-end bearing(rock crankshaft back & forth & check piston for response).
If the #2 cyl big-end bearing was totally stuffed, that could account for your low oil pressure once oil warms up, metal in oil fliter, & bent valve(piston hitting valve)."

"Small update, I disassmebled

"Small update, I disassmebled the oil pump and the head today. I can't see any signs of problems other than it is obvious the valves hit the pistons on all three cylinders. You can clearly see the dents on the edges of the valves where it hit. There are no bad signs of scoring or wear anywhere throughout the top end. It all looks fine.

Tomorrow I will take the rest of the engine out if I have time. May as well get to the bottom of it. The crap that is in the filter is not from the top end thats for sure."

how is it gowing?

how is it gowing?

"Yeah its been a while since I

"Yeah its been a while since I posted. Well I am completely slammed with the stuff I normally do and she did sit on the back burner for a while.

I've been back at it and found some very interesting new things, read on. Had a few friends come over and look at it too all of which have more experience than me with rebuilding blown motors.

I am not going to take the bottom end apart. The consensus is we likely don't have a bottom end problem. The tops of all pistons look good, the cylinders, the head, there is no signs of detonation or catastrophic failure. The top end is spotless in terms of having lubrication and never losing it. So we are hoping everything is kosher on the bottom.

New findings. When I pulled the float bowls off the carbs to have a look in there I was shocked at how much water was in them !! I mean lots of water you can clearly see it separating on the stainless steel surface where I'm working.
Then a few minutes after as I'm taking this stuff apart I'm all of sudden Mr. Sticky why are my fingers so sticky?? SUGAR!! May as well be a maple sugar candy bar. Go back to the intake manifold and start looking at that crusty stuff thats all over the place here and there, its all sugar.... Go to the boat and look at the gas fill, right below it on the side of the hull there is what appears to be a vent that is smashed off and obviously water has been going in it when he's operating his boat and contaminating the fuel. And somewhere along the lines someone has put sugar in his tank.

I'm gonna go ahead and rebuild everything on top correctly, install the timing belt correctly which is I think initally what happened somehwere along the way and wacked valves. Then I'm gonna clean out the fuel system and hope for the best. I'm also changing the oil pressure sender. Then we'll see what happens after that."

I rebuilt the water pump on my

I rebuilt the water pump on my BF15 and initially the water stream was very strong. I had done my best to clean all of the rubber debris out of the water system. Shortly after I noticed that the water stream was beginning to get weaker and weaker. I diasembled the water stream hose from the thermostat and the pisser nozzle from the engine housing. Briefly ran the motor connected to the garden hose with the hood removed to clear the system. Very small rubber pieces were blocking the hose and the nozzle. Once I cleaned these the water stream was again as strong as ever.

Final update. FIXED! Did w

Final update. FIXED! Did what I said I was gonna do in the last post. Boat runs like a clock. Man that was a lot of work and I officially don't like boats but the outboard engine is pretty sweet!!