Yamaha spark question.

I have been reworking a small 1997 15hp. 2 stroke yamaha. I have replaced almost everything... lol This project is getting out of control!!! Well rebuilt the carb, rebuilt the fuel pump ,cleared all the water passages and a bunch of other stuff... So I have been trying to get it started for 2 days now and I don't think it is getting spark. I closed up the garage so it is pitch black with the spark plugs out and tryed starting it to see if it is getting spark, well no spark!! Is that a good way to test the spark?? I don't know, but I thought it might be... Maybe needs coils??? Please help!

 

yes it is attached. Answers why when I touched the power head while cranking it, I got buzzed.

 

I unpluged the ground and white wire that come out of the kill switch but to no avail. I seem to think the motor isn't getting fuel. With a rebuilt carb and fuel pump, could it be the reeds? Yes I have a vented gas tank.... that always seems to come up. Anymore suggestions? The motor has good compression.

 

I bought the motor on the cheap from a guy who let it sit for 6 years. I have rebuilt several small out boards before but this one is giving me trouble. Originally all of the cooling passages were heavily clogged and the main water tube was shot. I pulled the power head and lower unit replaced all of the gaskets and the water tube. Rebuilt the carb just to be on the safe side and the fuel pump was all dried out so replaced all the internals. Now i can get fuel into the bow but after 20 time trying to start is I pulled the carb and the intake has no signs of fuel.

 

Most motors I replace the fuel pumps completely after tinkering with them, it was always easier to replace. But this model has the fuel pump built into the carb. When you remove the carb bowl the fuel pump is attached. I did blow compressed air through but didn't soak it in carb cleaner.... I WILL try that.

 

Well it has spark. I will compression test it today just to make sure. Worst comes to worst, I would have to hone the block and re ring the pistons. Been there, done that.

 

Did a compression check and it is a little low but almost even in both cylinders. 98 and 96. I know this is a little on the low side, but it should start. The carb bowl is full of fuel but it won't get into the cylinders to ignite. I am thinking this is a reed problem?

 

Okay after an afternoon I finely said F it and pulled the whole power head. I noticed some suspicious things while taking it apart. Looks like the reeds were replaced and the exhaust cover had been previously taken apart. Yep if it all lines up then this motor swallowed a reed and got stuck in the exhaust housing. Oh well it need new rings and a upper piston. It is heavily scarred and so is the exhaust housing. Not an exact newbie when it comes to this, but at 98psi compression I figured I could get it to fire, my johnny/rude fired with 50psi!!! There was so little compression that the reeds would not open hence why the cylinders weren't getting gas. Thinking about boring it .50 over, modifying the carb, and boyseen reeds just for kicks. I might have $400 into when I'm done and it might become a 17hp. LOL

 

Usually on other motor that I have played with in the past, I could put my hand over the intake and crank the engine. When I did this in the past I could feel the suction, but not on this motor.
They do make .50 over pistons, but I found a killer deal on oem ones. I can get both new pistons, rings, and pins for the cost of just one oversized piston.