Pictures of Hole in Piston and Boat at shop

[cheappc]

Here is the picture of my piston with a hole in it

also a picture of the old oil pump

Also my boat today picking it up at Inland Jet Sports Rancho Cucamonga.

 

[Dr Honda]

a hole burnt right under the plug..... Either preiginition... timing was too high... the fuel was VERY bad... The carbs were lean... or the squash band was set too tight. In the end... it's all because the combustion was too hot.


Why are they changing the pump? A hole in the piston isn't from lack of oil.

 

[cheappc]

ok...

wow....

So what did I do to cause this?

I used the best fuel, 76 91 octane, or Shell 91 octane.

Everything else you mentioned is chinese to me? lol

 

[Dr Honda]

If that was the PTO piston... the crank could have gotten out of index. OR... if the key sheared on the flywheel... it could have gotten out of time. (just trying to think)

With 91... it shouldn't have had pre-ignition.


Regardless... with a melted hole in the crown... you need to find the problem. If they are just doing a top end... it could happen again. Before running that engine, I would want them to do a leak-down, clean the carbs, and verify they ignition timing.

 

[DonoBBD]

Just what doc said. In your picture is exhaust port side of the piston facing to the left? Is the edge of the ring lands look like it is sand blasted?

This all leads to pre ignition or detonation. On a two stroke it sounds like a bee buzzing.

I would check the timing key for sure.

Don.

 

[cheappc]

Tony
They went ahead and sealed all the leaks?
Also went through the carbs again..
And went through the crank..

I remember when Seadooya came over one of the cylinders was reading 90 (the one that died), and the other one was reading 150..

So... Im not sure.. What does PTO mean again? Im gonna go ahead and try it today, he said I need to break it in, I cant go full throttle for the first 30 minutes...

Then kick back a little, and go at it again for 30 more minutes not full throttle again... so I can break in the motor....

 

[DonoBBD]

PowerTakeOff.

PTO.

 

[Dr Honda]

PowerTakeOff.

PTO.

Yup


It's the side that the drive shaft is hooked to. The crank can twist in the center, and give the POT jug a few more degrees, and do just like in the picture.

 

[cheappc]

Here are the videos I went out yesterday to Puddingstong Lake,
the boat was awesome!!!

Thank God, I had no issues what so ever, wow, knocking on wood, everything worked perfect, the boat started right up this time, turned off right away, launching and docking were a breeze, the water was warm!! unbelievable..

The engine sounded so strong, I am so happy unbelievable!

I am going to take a picture of the other piston and that one side by side so you can see,

here are the videos..

I didnt take it with my good camera the battery died...

http://www.youtube.com/watch?v=bolOaaIu3Ao

http://www.youtube.com/watch?v=sgECqeSGx6U

http://www.youtube.com/watch?v=bolOaaIu3Ao