Mixing gas and sbt oil at 50/1 after rebuild

[cornhusker]

I recently rebuilt a seadoo 717 with sbt top end. I mixed gas with sbt oil as directed. I did not close off the oil injection.
The ski will run great for a couple of minutes on the water. The moment i let off to bring it to shore it starts to bog down. I have ran thru 2 new sets if ngk plugs. Plugs arent necessarily wet rather they are black. Please note that i filled the tank up all the way mixed.
Should i drain half the tank and fill it up with gas to get closer to 100/1? I want the rings to set in good, but would like the ski to run too!
Thanks,

[Technical Support]

Re: Mixing gas and sbt oil at 50/1 after rebuild

Why did you do a top end? what damage was done to the old one?

[cornhusker]

Re: Mixing gas and sbt oil at 50/1 after rebuild

The ski sat for a number of years and had water in it. Top end and crank was bad. I tore it all the way down and installed sbt top end and used crank.

[Technical Support]

Re: Mixing gas and sbt oil at 50/1 after rebuild

You may have more of a fuel issue than anything else, go through the fuel system and the carbs

[cornhusker]

Re: Mixing gas and sbt oil at 50/1 after rebuild

I did a compression check. The PTO (rear) has 150 psi and Mag side has 115. I litterally have 30 minutes of run time on this ski! Unfortunately I didn't check compression after the rebuild. Can someone lead me in the right direction to resolve the issue? I am wondering if the rings didn't seat correctly or if one of the cylinders wasn't good upon putting it all back together. Please note that the walls all looked good and I wasn't able to dig my nails in any nics. Very very minor scuffing. Thanks in advance for all the help.
Thanks,

[Technical Support]

Re: Mixing gas and sbt oil at 50/1 after rebuild

It still sounds fuel related and the front cylinder being low on compression could be the result of the lack of fuel going to the cylinder. Does this ski have gray colored fuel lines on it? and has the carb or carbs been cleaned out or rebuilt?

[cornhusker]

Re: Mixing gas and sbt oil at 50/1 after rebuild

The ski still has the gray colored fuel lines which I assume were the original. I did tear down and clean the bottom half of the carbs. This includes the needle/seat, main and idler jets. I did not buy a rebuild kit and do the entire carbs. Looking at the schematics the fuel pumps are located inside the carbs and it looked to be a pain to install. Are you suggesting that if I tear the top end down again and the the cylinder walls look good it will more than likely blow up again unless I clean the carbs all the way and put a rebuild kit in it? That makes sense that it could be leaning it out.
Although I usually look at the cylinder walls good, is it possible that the Mag side has ovaled itself out a little, thus letting compression by?
Thanks,

[cornhusker]

Re: Mixing gas and sbt oil at 50/1 after rebuild

Update:
I removed the head to check for the possibility of a broken gasket. To my suprise nothing was wrong with the gasket, piston, rings, or sleeves of cylinders. OR at least the naked eye couldn't detect anything. So I put everything back together. To my suprise both cylinders are now at 120PSI. I used the same gaskets and retorqued the head down to 18 ft lbs. Now WTF!!!!
Both cylinders are low! Is it possible that I have a warped head? Please note that I only have about 30 minutes of run time on this motor. Do you need to replace all the gaskets everytime they are openly exposed?
Please help,

[Technical Support]

Re: Mixing gas and sbt oil at 50/1 after rebuild

behind the fuel pump is the fuel filter pushed into the carb, remove it and clean it out, replace all the gray fuel lines, clean the on/off valve out 100% and the carb with out the fuel pump ( if its dual carb ) in the same location as the one with the fuel pump will also have a fuel filter check and clean that too.

[cornhusker]

Re: Mixing gas and sbt oil at 50/1 after rebuild

One of the two filters was absolutely filthy. I soaked them overnight and plan on putting it all back together tonight. I will update later this evening.

Thanks,

[Technical Support]

Re: Mixing gas and sbt oil at 50/1 after rebuild

Sounds good

[cornhusker]

Re: Mixing gas and sbt oil at 50/1 after rebuild

Cleaning the filters fixed my problem. Thanks everyone for your help!