QD-15 just picked it up. couple of questions.

[mettyfish]

Just aquired a Johnson QD-15 pretty good shape with pressure tank. Noticed that the guy only had the fuel side of the hose hooked up. The air hose not hooked up. Seems like the air hose has shrunk and I can't get the hose on. I ran it a little with just the gas hose hooked up and it would run a while and stop. Did notice a couple times it would cough when stoping and spit a little out the air side on connector because no hose on it. Could you give me a description of how the pressure tank system works and do you have to have the air tube hooked up. I would think you do because its there for a reason. Motor seemed to pump water well. I would like to change impeller but do you have to take power head off. After my 9.5 issues I hate to bother you all but I have the outboard bug bad and have been picjing up a few motors off craigslist to work on and learn. Thanks for any info. Mettyfish

 

[jbjennings]

Re: QD-15 just picked it up. couple of questions.

New QD-15!! cool.
The primer button on the tank pushes fuel up to the carb and fills the bowl. When you get the motor running, the nipple on the intake manifold pushes air into the tank and pressures it up to only a few psi (less than 10psi so it's not dangerous like some folks say---it even has a pressure relief valve on it so too much press. can't build up) which pushes fuel into the carb from then on. So the primer is just to get it started, the air from the motor keeps the tank pressured up and fuel flowing. It's lean sneezing as the fuel bowl runs low and then dies, which is exactly what it should do.
Fear not, you can easily get BRAND NEW double line hose from various places. i use laingsoutboards.com for mine. They have lots of other goodies for your motor.
Love those QD's!!!

BTW, you don't have to remove the powerhead. Change the impeller the same way as your 9.5.
JBJ

 

[mettyfish]

Re: QD-15 just picked it up. couple of questions.

That all makes since now about how the tank works. Thanks, and I am thrilled I dont have to remove the power head. Just drop the lower unit a little and I can get to the shift shaft screw? Right Metty

 

[mettyfish]

Re: QD-15 just picked it up. couple of questions.

Oh and fuel ratio please. Thanks again. Metty

 

[jbjennings]

Re: QD-15 just picked it up. couple of questions.

Fuel ratio is 24:1. I like synthetic tcw-III since it smokes less and is biodegradable-----moreso than regular oil---supposedly....

There's a little 2" oval cover on the midsection, under which is the shift shaft connector. Just be sure on reassembly that you have the groove in the shaft perfectly aligned with the hole in the brass coupling or you will rub off the threads on your bolt.
Later,
JBJ

 

[mettyfish]

Re: QD-15 just picked it up. couple of questions.

Couple more questions. I got hose today and got the tank hooked up correctly. Runs pretty good other than it cuts out some. Seem like if I move the slow speed knob counter clockwise pretty far it does not sneeze or cut out as bad. What do I need to do with that problem? Go through carb. Pressure is building in tank because I unscrewed cap on tank and a burst of air came out.
I also replaced impeller and it went real well. Pumping about twice as much water now.
So I go to replace lower unit oil and I open the bottom screw and rusty water came out so I ran some gear lube through top hole down through bottom hole and a little crap came out. So I then filled it with new lube. Then pulled prop and there was a big ball of fishing line on prop shaft. No gear lube seems to be leaking though. Is there supposed to be a rubber or plastic seal on the lower unit gear lube screws? Seem like some motors have them and some not. Just metal to metal. I will keep eye on it. Thanks, Mettyfish

 

[lindy46]

Re: QD-15 just picked it up. couple of questions.

Turn slow speed needle clockwise until lean sneeze is noted. Then back the needle out 1/8 to 1/2 turn, a little at a time until sneeze stops. If it still runs poorly, carb may need cleaning/rebuilding. If there are no washer/seals on the drain screw and vent screw, water will get in the lower unit. They should be replaced each time the L/U is drained and refilled. If there is fish line around the prop shaft, there is a good chance the prop shaft seal has been compromised. I'd make sure to replace the drain and vent seals and see if it leaks before tackling the prop shaft seal.