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Old 05-07-2016, 09:27 PM   #1
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Low rpms

Hi folks!

Any thoughts about why my starboard Ford Lehman 120 won't go beyond 1600 rpm? Throttle cable? Or?

Thanks for your suggestions about where to look first.

Robert on "My Lady."
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Old 05-07-2016, 09:39 PM   #2
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--Throttle cable could have slipped. THe clamps that hold the sheath will prevent proper operation if they loosen. If they are loose the sheath will move instead of the core. Check both ends, the engine end and the control lever end.

--.fuel filters. If clogged will limit fuel available.

Have you tried to run the engine at full throttle out of gear?
Do it fully warmed up.
If the engine revs up fully then it likely is NOT the cable although I would still check the clamps as intermittent can be a problem. The governor will stop it over speeding. You only need do it for long enough to find out if the engine reaches its high idle speed.
It could still be a fuel restriction as out of gear requires a miniscule amount of fuel..

These are the most likely causes. I'm sure I've missed something.
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Old 05-07-2016, 11:17 PM   #3
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Engines off...
Do both levers go full forward at the helm?
If so do both cables extend the same at the engines?
If not, it's likely a simple loose "cable."
If both throttles at the engine reach the full open position then follow clectrics other suggestions.
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Old 05-15-2016, 09:29 PM   #4
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Quote:
Originally Posted by Bigfish View Post
Hi folks!

Any thoughts about why my starboard Ford Lehman 120 won't go beyond 1600 rpm? Throttle cable? Or?

Thanks for your suggestions about where to look first.

Robert on "My Lady."
Any luck?
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Old 05-16-2016, 02:25 PM   #5
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Quote:
Originally Posted by Bigfish View Post
Hi folks!



Any thoughts about why my starboard Ford Lehman 120 won't go beyond 1600 rpm? Throttle cable? Or?



Thanks for your suggestions about where to look first.



Robert on "My Lady."
Can you manually move the throttle linkage on the fuel pump (where the engine end of the throttle cable connects). Does this get the engine up to full speed?
Do you have fuel vacuum gauge? Any difference in exhaust color? Have you been aground lately? (Bent wheel).
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Old 05-16-2016, 03:59 PM   #6
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first? Change fuel filter. Do indeed check out of gear wot. Then look for something bent or on the prop.


After that report back.
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Old 05-16-2016, 04:34 PM   #7
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Could also be a faulty tachometer. Mine read low by about 400 rpm at WOT. I calibrated it back to specs with a laser tach.


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Old 05-16-2016, 05:15 PM   #8
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The out of gear wot test will verify the tachometer.
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