2QM20 throttle

Alctel

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Dec 13, 2013
264
Hunter 36 Victoria
Hey chaps

Does the throttle on your 2QM20 'stay' forward all the way? If I push my forward in forward gear I can get to around 2500 RPM, but as soon as I release the lever it slips back physically to around 2000-2100 RPM. Is this normal? I sounds very comfortable at 2000 RPM but I was reading it should maybe run at a higher RPM, in which case I am wondering if the lever should not be slipping back like that.
 
May 24, 2004
7,174
CC 30 South Florida
Has nothing to do with the engine, it is a malady of older boats. The throttle lever stays in place by friction and after many years of use the friction points wear down. I would wedge a piece of cardboard between the lever and the binnacle to hold it in place or device a more permanent fixture. Check the archives as I think some of the fellows have device a clamp to help the issue.
 

Alctel

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Dec 13, 2013
264
Hunter 36 Victoria
Interesting thanks, I'll take a look!

What RPM do people run their 2QM20s at? And what fuel burn are you guys getting? I'm at around a gallon an hour I think, or thereabouts
 
Jun 21, 2007
2,117
Hunter Cherubini 36_80-82 Sausalito / San Francisco Bay
A concurent thread on the same topic is happening right now on another SBO forum:

http://forums.hunter.sailboatowners.com/showthread.php?t=173825

And as Benny suggested, check the greater archives (not only Cherubini Hunters) for a range of solutions. Slipping throttles has been discussed many times over the years.

I have my own friction fitting, but the because I made a major repair to the cracking plastic throttle housing which afforded a means to integrate.
 

tmjb

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Mar 13, 2012
222
Hunter 36C Glen Cove
Mine has an Edson pedestal on which the stainless shafts that the shift and throttle levers mount pass through plastic plastic sleeves fitted into the aluminum housing. Both shafts have screws/bolts that pass through the aluminum which can be screwed in/out (assuming they are not seized of course) to increase/decrease the friction on the shaft. I thought this was standard on the Edson fittings. I believe Edson sells replacement plastic sleeves if needed (I purchased new for a different boat some time ago).
 
Nov 6, 2006
10,095
Hunter 34 Mandeville Louisiana
I think this was/is a standard on the old Merriman pedestals as well as the Edsons.. If you remove the compass, they are normally in the control shaft supports.. but a lot of boats now don't have the traditional pedestal and/or have single lever controls..
 

Alctel

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Dec 13, 2013
264
Hunter 36 Victoria
I have a yacht speciality pedestal

Thanks guys, I'll tighten the cable brake. All this time I thought the engine wasn't supposed to go above 2000 RPM!
 
Jun 21, 2007
2,117
Hunter Cherubini 36_80-82 Sausalito / San Francisco Bay
Hi Actel:

I am not sure your reference to "cable brake"? If you have the original Yacht Specialties housing, like I have, I don't recall ever seeing any OEM feature for controlling the friction of the throttle cable.

The pedestal housing has the wheel steering brake. I use it all the time!

About 1.5 years ago, recall that we had thread about the plastic throttle and gear shift housing on the Yacht Specialities housing. The link is below. I will call this piece the "puck". It has a serious weakness inside. The original design does fail after 25+ years. If you still have the original puck that hasn't been reinforced, give some consideration to modifying before you have a OMG moment! It isn't if. But WHEN.

http://forums.hunter.sailboatowners.com/showthread.php?p=1084640&highlight=housing cracks pedestal

Also here is a link to a thread in 2009. Maine Sail also contributed with a recount and photos of his very professional repair method (as we have been appreciatively accustomed to).

http://forums.hunter.sailboatowners.com/showthread.php?p=607878&highlight=housing cracks pedestal
 

Alctel

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Dec 13, 2013
264
Hunter 36 Victoria
I pulled the compass - it appears that there are no plastic parts in the pedestal levers - I guess a PO replaced them with metal? Unless I am looked at the wrong part, see pic.



I noticed the cable for the compass light was slightly caught under the throttle cable so I removed it.

I had a small cable clamp on the cable, so I tightened that and it fixed the slippage.
 
Jun 21, 2007
2,117
Hunter Cherubini 36_80-82 Sausalito / San Francisco Bay
Hi again Alctel:

I did look at your attached picture. Just to verify, the failure spot I am suggesting is not the bronze metal arms you are showing. Nor the metal "axle". Rather the plastic extrusions of the "puck". From your pic, this looks to me same as my OEM part.

Maybe hard to see if you don't remove it, but extending down are plastic molded extrusions or "arms" to which the morse cables sheathes are bolted to. That is where the stress cracks happen. If one of them breaks free (most likely the gearshift because is gets the most strain), then control of the engine is immediately lost.
 
Aug 16, 2009
1,000
Hunter 1986 H31 California Yacht Marina, Chula Vista, CA
The throttle brake on my Hunter was a very primitive clamp installed along the throttle cable that applied pressure to the cable jacket and hence the cable. I didn't care for the original version so I substituted a stainless U style pipe clamp [not sure the proper term].