Low RPMs

[Fausto Trujillo]

Here is an update. I checked the timing on my starboard engine, the one with lower rpms (7000) and yes, it was off, both exhaust and admission. I got it fixed. The result? well....now the engine gets to 8000 rpms but it is still 1000 below the port engine that revs at 9000. Now...I did not know that the impellers are different (pitch) from each other on these boats so I swapped them back again port to starboard and starboard to port, I may gain some more rpms. I will post the results tomorrow evening, taking the boat out tomorrow.

So ran a compression check on both engines. To a crazy result

Raman SBT#3
Revs to only 7k rpm(1500) below stock
Cylinders rich

All 4 Plugs look rich

Cylinder 1 152 PSI compression check
Cylinder 2 155 PSI
Cylinder 3 167.5
Cylinder 4 155

Original older engine runs perfect.

Plugs look lean


Cylinder 1 110
Cylinder 2 167
Cylinder 3 124.5
Cylinder 4 177.5

Hello

So ran a compression check on both engines. To a crazy result

Raman SBT#3
Revs to only 7k rpm(1500) below stock
Cylinders rich

All 4 Plugs look rich

Cylinder 1 152 PSI compression check
Cylinder 2 155 PSI
Cylinder 3 167.5
Cylinder 4 155

Original older engine runs perfect.

Plugs look lean


Cylinder 1 110
Cylinder 2 167
Cylinder 3 124.5
Cylinder 4 177.5

Hello.
Make sure you have a decent compression tester, it happened to me, I bought a good quality SNAPON and my compression was completely different (better and even)