2013 250 proxs rpm help

[mawilsoncobra201]

just had the #6 sleeve replaced and replaced all the pistons now motor will not run over 5000 rpm with 13hrs on break in tried 4 dif props 26 scorpion 26 tempest+ 25 4 blade and 24 scorpion all stay around 5000 to 5200 rpm

[lpugh]

Make sure it is getting full throttle at the throttle body!
.Check port alignment and verify pistons are in the right locations.

[mawilsoncobra201]

we checked all the above thats why we are at a loss

[DewRonInc]

Must have a failing coil. I actually found a problem with my crank trigger, it ran around 54 5500 and didn't want to go any higher. Now all good

[JOE54]

correct parts /pistons ????

[mawilsoncobra201]

new pro marine rebuild kit was used standard bore size

[JOE54]

pistons have domes or flat on top ,, important

[mawilsoncobra201]

domes same as ones that came out

[mawilsoncobra201]

port on port and starbord on starbord

[JOE54]

cyl drop test can determine non working cylinders to isolate problem

[mawilsoncobra201]

This is a 2013 250 proxs changed out the trim unit so dont know ser# all 6 cylinders are firing we have taken each cylinder while running and unhooked the fuel injectors and you can hear a difference each time All injectors air and fuel were sent off and cleaned and tested. new compressor also. Did a compression check all cylinders are at 95+ Motor was running 5000 rpm and turning the 26 scorpion 67gps when we found #6 was bad now same prop 5000 rpm 59gps

[lpugh]

This is a 2013 250 proxs changed out the trim unit so dont know ser# all 6 cylinders are firing we have taken each cylinder while running and unhooked the fuel injectors and you can hear a difference each time All injectors air and fuel were sent off and cleaned and tested. new compressor also. Did a compression check all cylinders are at 95+ Motor was running 5000 rpm and turning the 26 scorpion 67gps when we found #6 was bad now same prop 5000 rpm 59gps

serial number is on the swivel assy. starboard side, not the trim.
Fuel and air pressures at top speed are needed, dual glycerin filled gauges and a 3rd gauge on the low-pressure port. Report back with exact readings

Have you verified all pistons are installed in the right cylinders?
This can be done with good camera, most likely.

[mawilsoncobra201]

when we replaced the pistons with the new ones i didnt see any notation for cylinder other than port or starboard

[JOE54]

pistons marked up and or S,P towards top of block ?????

[mawilsoncobra201]

yes we have double checked the pistons

[JOE54]

do you have any way to do a cyl drop test to isolate a non working cyl at 5000rpm ??????

[mawilsoncobra201]

no we dont

[mawilsoncobra201]

dont even know how to do that

[mawilsoncobra201]

have 2 thoughts on what may be happening we changed the lower unit out with a older 1999 225 opti lower maybe dif gear ratio 1.87 not 1.75 will check that today but same rpm with 26-24 pitch props. Also going to switch out ECU from another motor

[lpugh]

can you get the serial number for the motor the lower came off of? Is it even a mercury lower, not SEI? good condition
Your motor most likely came with a torkmaster maybe a gen II
Got a pic of your old lower?
Joe or don can run the serial numbers.