Why does my Johnson 90 have cold-start issues once in the water?

[Danthehitman]

Hi everyone and thanks in advance for any advice you may have!

So, I've only only this boat as of this year, had it out for the 5th time this last weekend. I'm noticing it starts immediately when out of the water (using water-muffs, of course). I always test-start before heading out on the road. I have been using the 5-8 second prime after pressurizing the fuel-line and it starts like a charm. For some reason, once it's in the water, at launch and/or after sitting for 10 minutes on the water, it refuses to start at which time I have to use starting-fluid, then it'll start. I'm struggling to figure out what the problem is.

I notice the fuel pressure bulb behaves differently, typically at launch, like it doesn't want to pressurize. Other times, after sitting for 10 minutes, I can pressurize the bulb but still have no-start condition.

I've GOT to figure this out. Fuel pressure bulb is new, ruled that out.

Thanks, again.

 

[flyingscott]

Holding the primer in for 5-8 seconds does nothing, the primer is not a pump. Are you using the cold start lever? Are you holding the key in while starting? On muffs is not the same as in the water. What is your exact cold start procedure? I would also stop starting it with no water in the impeller. That will take its toll on the impeller then you will have bigger issues. Have you changed your impeller?. What is your compression?

 

[Danthehitman]

Holding the primer in for 5-8 seconds does nothing, the primer is not a pump. Are you using the cold start lever? Are you holding the key in while starting? On muffs is not the same as in the water. What is your exact cold start procedure? I would also stop starting it with no water in the impeller. That will take its toll on the impeller then you will have bigger issues. Have you changed your impeller?. What is your compression?

Hello Vince, I read about that cold-start "5-8 second hold" from some iBoat forums that many swore it helped in cold start scenarios. Here's my start process: 1)Pump-up fuel pressure bulb, 2)Fast-Idle fully up, 3)Push-in key while cranking and/or 5-8 second hold (as previously mentioned). *5-8 second hold seemed to make it fire-up faster than ever before.

I have not changed impeller. Only work I've done has been new plugs/wires, fuel-filter, fuel-pressure-bulb.

My compression numbers didn't look that great. 90, 90, 85, 90. Some have suggested I get another comp-gauge to verify.

Engine runs like a champ once running...after about 10 minutes in the water it doesn't want to start w/out starter fluid. (when starting immediately after shutting-off it also starts immediately. *Cool engine in-water = no start w/out starter-fluid.

Thanks

 

[flyingscott]

You have a compression problem Get a different gauge before anything else. Holding the key in without the starter turning does nothing. My name is not Vince.

 

[racerone]

Primer is to be activated by pushing in the key and holding it in while cranking.----There are a number of things (age / wear & tear ) that will cause the " no start in the water " condition.