2005 175 optimax, how do I test compressor and fuel pressure

[SparkieBoat]

I have good sparks and compression. I just got this motor. It ran great for 5 mins up the river. then when I idled it started acting funny, When I tried to throttle up it slowly bogged out and after about 30 secs it shut off and would not restart. How do I test the compressor air and the fuel pressure if it will not run?
After trying to start it, I have fuel pressure spit out if I press the top shcrader valve in, If I push the bottom valve I get nothing no pressure at all.
Any other tips and hints appreciated as this is my first opti.

 

[schematic]

cranking for 10 seconds or so should yield approx 80 psi air at lower shrader. If not....belt,compressor, reeds or tracking valve could have failed. you should get a service manual as this is a complex engine.
Connect to the upper shrader to check fuel pressure. should get 90 ish psi

 

[SparkieBoat]

Thanks a lot Schematic, I will get a manual soon. Right now the air compressor is not putting out any compressed air at all, when I spin the engine over I get no pressure build up on the hose going out to the fuel port rail. I am ordering a new reed plate assembly. (I found one on the cheap)
The piston seems to be in good shape, there is a very small amount of wiggle, but it seems about like I would expect. If it is not the reed plate, I guess I will have to take the piston out and hone the cylinder and new rings.

 

[schematic]

Should be obvious if its the reeds. Look for signs of overheat as well. Follow the coolant hose from the air pump to the engine. There is a screen on the engine side hose fitting that can plug, causing pump overheat.

 

[SparkieBoat]

Hello Schematic, the reeds look ok. I will check out that coolant line, That is a great piece of advice, thank you for that.

 

[SparkieBoat]

Should be obvious if its the reeds. Look for signs of overheat as well. Follow the coolant hose from the air pump to the engine. There is a screen on the engine side hose fitting that can plug, causing pump overheat.

You win the golden prize schematic, the water filter was clogged, the piston rings are shot from over heat. Thanks for the advice you were right on target. Got an extra optimax compressor piston laying around anyone?

 

[SparkieBoat]

is it possible to purchase a new compressor piston and rings from anywhere?

 

[schematic]

no luck on pistons.....aftermarket should jump on this as there is a demand. Watch your telltail closely, as it gets it flow through the compressor. If the tell tail is weak, compressor cooling is weak. Kind of a good plugged screen indicator.

 

[SparkieBoat]

yes I noticed that when I was flushing the lines that the water leaving the compressor went out the tell tell hole. That is certainly something to watch for. I also found out that they have a separate over heat alarm wire for the compressor. I had to run a separate wire to the console and tie it into the alarm. the alarm seems to be working fine now.