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J&T 6-71 TIB Idle Adjustment

Ok, do you know how to access high speed spring and idle speed adjustments screw? They are located under an elongated cover on the side of the governor housing held on by two 1/4" bolts.

The idle speed adjustment screw is the small screw with a jam nut on it in the center of the assembly. Sometimes they have an Allen headed socket and sometimes they have a slot for a screwdriver..

Loosen the idle speed jam nut and back out the buffer screw (located on the side of the housing 90 degrees from the speed adjustments) at least 5/8".

With the engine running, adjust the idle screw in to increase RPMs or out to decrease. Stop and lock the adjustment about 15 to 25 RPM lower than your desired setting and then bring the buffer screw back in to increase the rpm to the final desired setting. DO NOT increase idle speed with the buffer screw any more than that. If you end up with an "engine roll" or hunting at idle after that, then the rack is out of adjustment or there is wear in the governor or fuel control linkage or pins.

Good luck.
 
Thanks, Ill be on the boat friday and ill take a good look before i touch anything. I do remember I had a mechanic when I first got the boat adjusting around thier. He only wants to come back for 8hr at a time now. Thanks again ill take a good look at whats their.
 
Are you adjusting the idle because it recently changed?

If your idle is too low, it could be that the jam nut on the idle has come loose and, when that happens, they always eventually start to back off and lower the idle.

But, if your idle has suddenly started to increase, that could be a problem that needs to be evaluated prior to trying to just adjust the idle setting.
 
I found the the Jam nut and idle slotted screw but did not see the buffer screw. I beleive we had adjusted the rpm to 550 its now about 600. So yes it increased since spring of 2010. So you are thinking its not just idle adjustment?
 
If you look at the engine from the front and imagine the governor housing as a box that sits on top, then the buffer screw would be on the left side of the box. Sometimes they come loose and "drift" in on their threads. This would have a tendency to raise the idle and could cause a problem if it goes in too far. Check that out and if it seems that's what might have happened then just go through the procedure and re-set the idle where you want it. Factory spec is 400-450rpm so you had it pretty high before.
 
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