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post #1 of 3 Old 02-18-2013 Thread Starter
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Yanmar 4GM Shift question

On my Endeavour 38 the engine when idling at high rpm has a tendancy to jump in forward. When engaging the shifter its a short throw. Reverse is a good solid move. Trying to figure out where to look. Just bought this boat recently and hoping it's out of adjustment. Also the engine blew white smoke a lot on cranking but leveled out after running a bit. Surveyor and several others said it was most likely clogged injectors.....been sitting awhile. Said to try fuel cleaner first but trying to decide which one to use with so many on the market. Thoughts were to put some cleaner in first then try and pump out the fuel before putting in new injectors. Engine runs smooth and cranks easy enough. Any advice or thoughts appreciated
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post #2 of 3 Old 02-19-2013
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Re: Yanmar 4GM Shift question

I would remove all the fuel from the tank and clean the tank, change all filters, and then add all new fuel with a biocide and a fuel injector cleaner and lubricator. Not sure of your tank access, but really need to see what is in your tank after pumping all the existing fuel out. To make this easier, try contacting a local fuel polishing company (one recommneded by a good boat yard or other boaters). They may be able to filter and reuse your fuel, or dispose of it legally if it is no good. Most of the fuel biocides and injector additives seem to work although some boaters swear by them and others say they are a waste of money. If used per directed they should at least cause no harm.

I think you shifting problem could be fixed with proper adjustment of the shiter, shifter cable (might need lubrication), and cable connection at the transmission. Also check if engine vibration is in some way causing the transmission shift linkage to "shift" the transmission- maybe a loose transmission/engine mount.

Last edited by casey1999; 02-19-2013 at 06:50 PM.
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post #3 of 3 Old 02-19-2013 Thread Starter
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Re: Yanmar 4GM Shift question

Thanks for the advice. I'll do some asking around on the fuel polishing. Getting the tank out would be an ordeal. My last boat I was ablke to get it out and then cut some ports on top to be able to clean it. This one looks like it was set and everything built around it with little thought to it ever coming out. Have not had a chance to stare at the shifter but will start plundering around the abyss checking that area out soon.
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