550 experts help. Good spark lots fuel. No run

truerider411

truerider411

Location
alberta, canada
hi guys. I rebuilt a 91 piston port 550. Everything is good I just confirmed that timing is at zero. It's getting amazing amazing spark, turning over extremely fast. I've put fuel down the carbs (race fuel) no fire. Not even a sputter. Not even with carb cleaner. Now I checked the compression and I'm at 90psi. The reason I did this rebuild is because buddy said his motor seized. After ripping his motor apart and finding nothing wrong I discovered the pump was seized. No biggie rebuilt the pump and decided to powder coat the motor and make er pretty. Buddy said ski ran great prior to pump seizing so I decided not to bother with piston rings however I put all new sbt gaskets on it. And now nothing. Any help or suggestions? Is 90 psi just to low. I know stock is around 120-130 I was just hoping once I got the ski to run maybe the rings would seat a little better
Thanks.
 
_evan

_evan

Location
3 stacks and a rock, California
90 psi is really low for an engine. mine was at 125 per hole and I rebuilt it and brought it up quite a bit (around 150-155 per hole) Its probably turning over super easy because it has next to no compression.


also a little info on fuel and octane level. The higher the octane number the more pressure and heat it needs to ignite it. so, 87 octane is actually MORE flammable then race gas. The only reason why you would ever want to run high octane fuel in your engine is to prevent detonation in your engine (the fuel going off due to pressures in the engine rather then spark). so running race gas in your stock engine will actually lessen your horsepower output and performance.
 
Nottjbarlow

Nottjbarlow

_evan said:
90 psi is really low for an engine. mine was at 125 per hole and I rebuilt it and brought it up quite a bit (around 150-155 per hole) Its probably turning over super easy because it has next to no compression.


also a little info on fuel and octane level. The higher the octane number the more pressure and heat it needs to ignite it. so, 87 octane is actually MORE flammable then race gas. The only reason why you would ever want to run high octane fuel in your engine is to prevent detonation in your engine (the fuel going off due to pressures in the engine rather then spark). so running race gas in your stock engine will actually lessen your horsepower output and performance.
Click to expand...

+1
Race gas should ONLY be run in a machine when it's needed!
 
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