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2005 Mercury 60hp ELPTO need some advice

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!
 
It will idle like that and bog it bleed restrictor are missing...under front intake and easy to fall out during reassemble
 
Thanks for the quick reply guys!

Sounds like the idle mixture is off a bit.

Jeff
I adjusted them once out on the water in gear. Never could get it to where I liked it and gave up. I adjusted them lean first, then rich and then tried to find a happy medium on the richer side. Every setting I tried made very little difference.


It will idle like that and bog it bleed restrictor are missing...under front intake and easy to fall out during reassemble

That is interesting! Where are the "restictors" located? Pardon my ignorance... Are there 3 of them? If so could you elaborate? Is there one for each carb or just one on the bottom?
 
I spent quite a bit of time on this today and I think I pretty much have figured it out. I followed the Mercury shop manual and it got me close to where I need to be. The rest is just a little fine tuning.

At cranking speed, I checked the idle timing and it was 2 BTDC. I also checked the Max. timing and it was set at 24 BTDC. The sticker on the engine says 22 BTDC. After adjusting idle timing to 0 TDC and Max. timing to 22 BTDC I moved on to the carbs.

Upon inspecting the carbs I found they were not in sync. So, I synced the carbs (again) and moved on to the cam follower adjustment. I set the follower on the looser side of the setting and did the final setting along with the idle mixture setting on the water.

It is odd, because as I stated above, I checked a lot of this stuff when I got the engine back and now it is out of wack only after 8 hrs of run time? Is this normal?

In the end and with the engine running I wound up with the idle timing being around 2 ATDC and an idle of 700 RPM in gear. I also played with the idle mixture adjustment again and got it to what seems to be closer to where it should be. The toughest part was adjusting the cam follower and getting it in the right position. It seems that for me the tighter the gap the better. If the gap was looser it would sputter a bit off idle. So, it is on the tighter side of the spec as listed in the manual. Off idle now the engine is smooth. There is still a slight vibration from around 1200 to 1600 RPM and I believe that this is from the carbs still not being properly sync'ed. Following the procedure in the manual is obviously not enough to properly sync the carb linkage. I plan to have a helper tomorrow "preload" the cam follower so I can tighten the other 2 screws on the top and bottom of the linkage. By following the manual, the center carb opens just barely before the other 2.

I think the key points here were to follow the manual to the letter in regards to the sequence of doing all of this stuff. When I did it the first time, I may have skipped around a bit and that could be what threw things off.
 
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