Throttle Question

[DaBod]

Hi all,

My apologies if this has come up before; I did some searching and didn't find anything. I just have a quick question. My Hunter 27 still has the original Renault RC8D, which, luckily for me, still proves very reliable. My question is that the throttle doesn't stay in position. If pushed open and left untouched, it will work its way back to a high idle. This is my first experience with a diesel, so I am unsure if that is normal or not. On all of the inboard powerboats I've owned/driven the throttle would remain when untouched. I've read in a few places that it is a safety feature that will prevent overspeeding should the spring or cable break, but it just seems kind of odd and inconvenient. In the interim I've found that a wine cork wedged between the throttle lever and pedestal works as a makeshift cruise control...

[daddle]

Add another spring at the engine end. Or a smaller spring at the lever end. Or add some more friction somewhere. But friction is generally bad. The foolish PO of this boat added u-bolt cable clamps to the Morse cable. Nice expensive friction free cables with added friction. Sheesh!

BTW: On a most diesels it is a speed control, not at throttle.

[roverhi]

If it's a single handle control, there is probably a friction setting on the throttle handle shaft. On the Morse controls, it's an Allen screw. IIRC you have to take the control handle off to get at it. Could be wrong on the location, it's been awhile.

If the control doesn't have a friction setting, Someone makes a clamp device to put on the throttle cable that works to hold the throttle in position.

[kmaz]

Perhaps related, perhaps not. Was having an issue with both reaching and maintaining full throttle. She wouldn't hit 900 short of redline and would slowly come back to about 1500 RPM. Went through the usual prop, fuel, air troubleshooting. No problems. Pulled the exhaust riser and sure enough she was badly corroded/clogged. Replaced with new and she not only hits redline but maintains it. No changes to tension or springs on the throttle control.