Motor trouble! !!
 

Question for a friends boat Yamaha 50 2 stroke. Ran fine on the first run. Then on the second run, got on it hammer down and sound like it had no power, barely idle speed. So backed off and engine would sputter got on it again, same thing.

compression is good on all cylinders. Sounds like a power pack too me. What yall think??

sent from my Galaxy NOTE II

Sounds like it to me

Power pack???

Check the bulb on the fuel line!!!! Have had the same experience twice in my many years on the water, and the bulb not holding pressure was the cause.

losing fuel pressure or bad gas...clean carbs and check fuel lines...my 40 does the same thing when bad gas clogs carbs

I have a yamaha and it did the same thing,brought it to the shop and mechanic said it was a dirty carb,bad gas etc,drained the gas and cleaned carb and 178 dollars and been fishing happily ever after.Good Luck

before he bought the boat previous owner had the carbs were cleaned. new owner changed the old gas line and bulb bc the old one was leaking at the nipple on the gas tank. though it might be air causing this problem but it isnt.

bulb was holding pressure the hold time never lost its prime.

Get a clear 2 liter bottle. Remove the wrapper. Squirt gas out of tank into it. Let it set and see if it has water in it. If not get a manual and check powerpack and your other electrical parts

Water/trash in the gas like the others say. The ethanol gas that is sold today is terrible for that. I try to only put non ethanol gas in my boat for just that reason. Another thing to do is to use Marine Stabil. I try to put it in every tank especially if I'm going to leave the boat sitting up for any time.

Yep, dirty carbs, my Yammy 50 hp 2 stroke did the same thing, get the carbs cleaned.

Could the nipple on the motor that connect to the gas line being loose cause this problem?

pull and clean the carbs again.

after all that take your plugs out & put new ones when they flie out it will do the same thing, also a coil will do the same good luck