QD16 idle issue

[sbump52]

My QD16 motor runs very well for its age. I checked the gap on the points the other day and they were a little close when I checked them with a feeler gauge, so I adjusted them to .020 and cleaned them up a little. (They looked fine) I took it out yesterday, started on two pulls after setting for about a month. Fired on the first pull, pushed choke in and started on second. Started on first (actually half way between the first) pull each time after that. The problem I noted was that it won't idle very low. Put the GPS on it and the slowest it will go is 2.5 MPH by the GPS. It is on a 12ft alum boat. It seems a little high idle for shifting also. I checked the timing plate base and the end of the base where the roller starts to fall off the end doesn't quite fall off. In other words there is still a little plate left over. Could I adjust that plate a little so it lets the butterfly close a little more? Other than that it seems to be running good. No hesitation and easily planes out the boat with a heaving trolling motor battery in the middle and my lard butt and gear. Checked top speed with GPS and it was up to 18 MPH with more throttle to go. A little too rough water to open it all the way.

 

[Daviet]

Re: QD16 idle issue

At idle the throttle plate should be completely closed. Adjust the plate a little to get the plate to close.

 

[sbump52]

Re: QD16 idle issue

Thanks for the reply, I think I will adjust it a little to see if that helps. One other question. I mix the oil 25:1. Is this correct or should it be 24:1? Not much difference, but just wondering which is better. Also us Stabil and an occasional shot of Seafoam.

 

[Daviet]

Re: QD16 idle issue

It sould be 24:1. I use sea foam every time in the gas tank, over the long run it will help with carbon build up and it is a fuel preservative.

 

[jbjennings]

Re: QD16 idle issue

Sounds to me like your slow idle mixture adjustment is off. If you haven't checked it, post back and I'll post a link on how to adjust it. You can't adjust the throttle plate itself, but can adjust the synchronization by adjusting the cam on the armature plate. I personally haven't found them to be bad about getting out of adjustment that often. I'd try turning the slow idle mixture knob clockwise in about 1/16 turn increments and see if you can idle it down a little more with the throttle, then if it starts "sneezing" open the mixture adjustment a little until it stops sneezing and idles smooth. IGnore the "start" and "slow" and "shift" marks on the throttle handle, they don't mean much. I've got a qd-16 also and really like mine.
good luck,
JBJ

 

[sbump52]

Re: QD16 idle issue

Cool thanks.

 

[sbump52]

Re: QD16 idle issue

JBJ I turned the low speed knob to the left toward the lean side and no help. Turned to right, to rich and it helped slow it some, but ran out of adjustment. Should I take the knob off, turn it to the right some more and put the knob back in the middle? Or adjust the timer base. When I first got the motor someone had moved the base quite a bit and it took a post or two on here to find out where it is supposed to be and do a link and sync.

 

[jbjennings]

Re: QD16 idle issue

Just push in the face plate and it should let your knob make another turn. If not, then take the knob off and get it past the stop and keep going. DO NOT overtighten. Be really gentle so that if you close it all the way you don't bend the needle point. It should die before you get it closed anyway, though.
BTW, I believe clockwise is leaning it and counterclockwise is giving more fuel and enrichening the mixture with fuel.
It may be WAY out of adjustment, because leaning it out will speed up the idle a little right before it leans it out too much and it starts lean sneezing on you. I like to start about 1 1/2 turns out from gently seated, and usually wind up about 1 turn out for a good idle. They all vary a little, though. The main thing is it idles nice for you. If you can't get it to idle really slow and reliably, then something's still wrong because those are very smooth idling motors. Make sure your 7/16 nut is holding a bind on your needle so it doesn't vibrate back out of adjustment.
Good luck,
JBJ

 

[sbump52]

Re: QD16 idle issue

Thanks I will try it out the next time out, maybe tomorrow after work.

 

[sbump52]

Re: QD16 idle issue

Thought I'd post an update. Got the motor to idle down, but ran a little rough in idle. Was leaking gas around the connector. Replaced the two o rings in connector and it will idle better, and gained one MPH on the top end. Now the boat will go 19.3 WOT by GPS on my 12ft alum. boat loaded. Starts half way through the pull. Thanks iboats!