Throttle Adjustment - how difficult
#1
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Thread Starter
Throttle Adjustment - how difficult
Twin 525efi motors, Livorsi throttles. At idle, to get engines at exact same RPM, port throttle is forward almost 1/2" of starboard throttle. Same thing under power, cruising on plane, throttles separate by close to same amount. Maybe a bit less. The difference is a 100 RPM across engines or so if I recall.....
If running twin screws, are your throttles dead even?
Am I expecting unrealistic perfection?
Is this something I should get fixed, if so, how difficult to do? If easy, may try it.
Thanks,
If running twin screws, are your throttles dead even?
Am I expecting unrealistic perfection?
Is this something I should get fixed, if so, how difficult to do? If easy, may try it.
Thanks,
#2
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It's quite simple to fix. You have adjustment on both the engine side and on the throttle side. It's obviously easier to adjust on the engine side. Which ever engine/throttle is advanced farther then the other (at the same rpm), that is the one to adjust. Simply remove the throttle cable end from the throttle body. Loosen the lock nut and unscrew the end about 2-3 full turns. Put it back together and see how close they are. If need be, adjust a little more at a time. Only change in 2-3 turn increments.
Whenever you adjust the cable ends, just be sure to check the throttle to be sure that it closes all the way. You also want to check WOT.
Eddie
Whenever you adjust the cable ends, just be sure to check the throttle to be sure that it closes all the way. You also want to check WOT.
Eddie
#5
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Eddie, after looking at some pics, are you talking about loosening that lock nut bow side of the cable assembly, then turning/tightening that barrel assembly on the end?, thus when you go back to mount in on the throttle plate, it pulls the slack out of the cable. as you said, 2 or 3 turns at a time. doesn't take much.
Do yo have to loosen the hex lock nut on the stern side of the assembly? Doesn't appear you would have to.
Thanks!
Ian
Do yo have to loosen the hex lock nut on the stern side of the assembly? Doesn't appear you would have to.
Thanks!
Ian
Last edited by imartin; 06-17-2015 at 06:31 PM.
#6
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You want to work on the engine that has the throttle that is farther advanced when the engines are at the same rpm. On that throttle body, loosen the jam nut on the cable end that is closest to the throttle body. You want to screw the end in so that you make it shorter, removing some slack so that the throttle will open faster evening them out.
Yes, only 2-3 turns at a time.
Eddie
Yes, only 2-3 turns at a time.
Eddie
#7
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Thread Starter
Ah, now I get it. Perfect! I will make an attempt at it. Thank you very much Eddie, I read great things about you on this boating forum. I concur with the positive feedback from others......
#8
While you are in there, make sure that when you lay both sticks all the way forward, the butterflies (throttle bodies) are fully open as well.
This could be robbing you performance if not.
If you have a Rinda or other scanner, you can check to see that they are digitally reading the same percentage of open at any given throttle position; by looking at the Throttle Position Sensor output. Do this with the engines off, but ignition on.
Be very careful not to drop anything down the throat of the TBs.
The new Mercury engines with DTS are actually "self aware" in that the computer(s) talk to each other and digitally match RPMs, etc. on all engines, twins or more.
This could be robbing you performance if not.
If you have a Rinda or other scanner, you can check to see that they are digitally reading the same percentage of open at any given throttle position; by looking at the Throttle Position Sensor output. Do this with the engines off, but ignition on.
Be very careful not to drop anything down the throat of the TBs.
The new Mercury engines with DTS are actually "self aware" in that the computer(s) talk to each other and digitally match RPMs, etc. on all engines, twins or more.
Last edited by Sydwayz; 06-19-2015 at 08:30 PM.
#10
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Thread Starter
Tackled the job today, couldnt have been any easier...Didnt even have to take the whole assembly off. did 2 turns, tested it, did another turn, tested it, backed it off 1/2 turn for a perfect match.
2.5 turns on the barrel. ....
Thanks all (for saving $95/hr in shop labor)!
2.5 turns on the barrel. ....
Thanks all (for saving $95/hr in shop labor)!