snookwhaler
Regular Contributor
I recently had my 2005 Mercury 60hp ELPTO powerhead rebuilt by a local reputable builder and I have some issues and questions. If anyone has any experience with this sort of thing, I sure would appreciate the help.
I had the powerhead rebuilt because of a "ticking noise" at idle and up to around 2900rpm. Turns out 2 of the cylinders had bad piston slap. All holes were bored .20 over to get rid of the grooves and new pistons, rings, seals, etc. were installed.
So, far I have had the engine on the water only a total of 8 hrs. and I'm still breaking in the rebuild. The problem is the that the idle is a little rougher than before and there is a vibration or shake from 1100rpm to about 1900rpm. Almost as if the timing is off or it's running on 2 cylinders every now and then instead of all 3. Also, right around 2800rpm there is a shudder and then every thing smooths out over 2900rpm. From 2900rpm and up it runs beautiful and smooth.
Oil injection system was removed a long time ago and this engine runs premix. I have been running 40:1 for the break in as per requested by the rebuilder and will continue to do so for about 1 more hour, then switch back to 50:1.
What I have done:
1. I have been through the carbs with new kits and they are absolutely spotless with no issues. All fuel lines are in excellent shape under the cowl.
2. All fuel line in the boat is new to include a new fuel tank.
3. New spark plugs.
4. New fuel filter.
5. Just checked compression (again). It is strong and even at 128psi across all 3 cylinders with throttle plates closed.
6. I just rechecked the carb. linkage and verified that all 3 are sync'ed.
7. I just rechecked clearances at the throttle bellcrank and cam follower alignment.
8. I just rechecked the crank WOT timing at the stop and it is 22 BTDC at cranking speed.
9. All plugs look about the same with no issues on any one particular plug.
10. I pulled all the plug wires one at a time at idle to verify that they are firing. The engine bogged just a little when each one was removed.
Perhaps a bad coil or plug wire? Or maybe just a timing issue?
One thing that is odd is it states in the owner manual that idle speed should be around 750rpm in gear and timing would be 2-6 ATDC. At that rpm in gear the timing is 2 BTDC?
Any help or advice greatly appreciated!
I had the powerhead rebuilt because of a "ticking noise" at idle and up to around 2900rpm. Turns out 2 of the cylinders had bad piston slap. All holes were bored .20 over to get rid of the grooves and new pistons, rings, seals, etc. were installed.
So, far I have had the engine on the water only a total of 8 hrs. and I'm still breaking in the rebuild. The problem is the that the idle is a little rougher than before and there is a vibration or shake from 1100rpm to about 1900rpm. Almost as if the timing is off or it's running on 2 cylinders every now and then instead of all 3. Also, right around 2800rpm there is a shudder and then every thing smooths out over 2900rpm. From 2900rpm and up it runs beautiful and smooth.
Oil injection system was removed a long time ago and this engine runs premix. I have been running 40:1 for the break in as per requested by the rebuilder and will continue to do so for about 1 more hour, then switch back to 50:1.
What I have done:
1. I have been through the carbs with new kits and they are absolutely spotless with no issues. All fuel lines are in excellent shape under the cowl.
2. All fuel line in the boat is new to include a new fuel tank.
3. New spark plugs.
4. New fuel filter.
5. Just checked compression (again). It is strong and even at 128psi across all 3 cylinders with throttle plates closed.
6. I just rechecked the carb. linkage and verified that all 3 are sync'ed.
7. I just rechecked clearances at the throttle bellcrank and cam follower alignment.
8. I just rechecked the crank WOT timing at the stop and it is 22 BTDC at cranking speed.
9. All plugs look about the same with no issues on any one particular plug.
10. I pulled all the plug wires one at a time at idle to verify that they are firing. The engine bogged just a little when each one was removed.
Perhaps a bad coil or plug wire? Or maybe just a timing issue?
One thing that is odd is it states in the owner manual that idle speed should be around 750rpm in gear and timing would be 2-6 ATDC. At that rpm in gear the timing is 2 BTDC?
Any help or advice greatly appreciated!