hp 500efi rev limiters
09-18-2009, 07:33 AM
#21
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to get this correct put the motor in base timing mode, run it to 4000 rpm and set the timing on 4000rpm. I watched them set the timing on the motor and it was not done that way. If you have a set procedure please explain, also I have a rinda scan tool available to me what can I check for to make sure it is done properly.
You put the motor in base timing mode and you only need to rev it to 1250-1500 and set it at 8 degrees. Some cals call for 10 degrees. Also some engines do not like the 34 degrees total the spark retard kicks in and it loses power.
09-18-2009, 11:04 AM
#22
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After the timing is checked maybe do a leak down. I did have a bad valve job from a machine shop on a new motor. Ran it on the dyno and didn't do to well. The leakage on one cylinder turned out to be 40%. I ran it again on the dyno in the exact same config and picked up 25 hp. Just a thought.
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09-21-2009, 07:09 PM
#23
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Have not had a chance to check timing will try this weekend, I did run it a few weeks back with the rinda tool on it to see if it would advance at 5250 and it did but the motors were off like 2 degrees from each other. I was by myself and did not have alot of time so I will try it again with some in the boat with me. trying to go wide open and look back at that monitor on the back seat is not easy. Thanks for the input.
09-21-2009, 10:36 PM
#24
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that's not thrue, you put them in timing mode (we use the dtt or newer laptop) and you time them on 4000, like a carb engine, that way you are 100% you have the complete timing degrees available, had the exact problem before, was a mercruiser factory tech who told me and turned out just fine
Please enlighten me. What was the timing at 4000 rpm? I can't believe me and every other engine builder have been doing this wrong for the last 20 years.
You can not check total timing with it in base timing mode. The ecm will add 10 deg. past 1800 rpm when in base timing mode. Total timing is determined by the calibration. It is based on the initial timing, which is usually 8 deg on Mefi 1,2,and 3. Usually the Mefi 4's use 10 deg. If the initial timing is set correctly, then the timing will be whatever is programmed in the cal. If initial is set at 12 deg., then there will be 4 more deg. of timing throughout the entire cal.Eddie
