In spring I rebuilt my 1997 780 SLT engine, upper and lower. A rebuilt crank from SBT, and I rebuilt my carbs. I pressure tested the engine and did the Pop off correctly for the carbs. Use quality oil as 40:1 pre-mix. No inject
At WOT it ran great, then would start to loose power, I would back off the throtle and it would start to rev full again. So it really seems like it is starving for gas.
Then yesterday, after only 20 minutes on the lake, it lost all power and only went to 3000 rpm. At home did compresion test, 3 good, 2 not as good, 1 dead.
Removed head, hole in #1 piston. Spark plug does not look like it has been running lean, but may be due to trying to run it for 10 minutes with hole in piston.
I now want to add a second fuel pump to supply #1, the post state that # 1 starves for fuel on these PWC's, even though each carb has it's own line going to it. The post state that #1 gets the left overs from 3 and 2. Not clear on that, like I said, there is a line going to each carb, so can someone tell me why they think #1 gets the left overs.
I want to put this back together with a new top end and the second pump, but I also read on threads that to check the crank phase to put #1 at TDC and the other two should be in the exact same place. Is this correct? my #3 is about 3/8 inch lower than #2. Is my crank out of phase? This is a rebuilt crank from SBT, told me it was welded so it could not do this, and I do not wave jump. I read it is what twist the cranks from the sudden hit on the water really toques the engine.
I do not want to do a top end on this engine if the crank is out of phase, am I doing this right to check it this way?
At WOT it ran great, then would start to loose power, I would back off the throtle and it would start to rev full again. So it really seems like it is starving for gas.
Then yesterday, after only 20 minutes on the lake, it lost all power and only went to 3000 rpm. At home did compresion test, 3 good, 2 not as good, 1 dead.
Removed head, hole in #1 piston. Spark plug does not look like it has been running lean, but may be due to trying to run it for 10 minutes with hole in piston.
I now want to add a second fuel pump to supply #1, the post state that # 1 starves for fuel on these PWC's, even though each carb has it's own line going to it. The post state that #1 gets the left overs from 3 and 2. Not clear on that, like I said, there is a line going to each carb, so can someone tell me why they think #1 gets the left overs.
I want to put this back together with a new top end and the second pump, but I also read on threads that to check the crank phase to put #1 at TDC and the other two should be in the exact same place. Is this correct? my #3 is about 3/8 inch lower than #2. Is my crank out of phase? This is a rebuilt crank from SBT, told me it was welded so it could not do this, and I do not wave jump. I read it is what twist the cranks from the sudden hit on the water really toques the engine.
I do not want to do a top end on this engine if the crank is out of phase, am I doing this right to check it this way?
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