Stall in water idle only

csvencer · #1 07-22-2010, 07:14 AM

Similar to Carl's problem but I didn't want to hi jack his thread. 98 Johnson 175 2 stroke, carbed that won't idle in the water. On the ear muffs it has no problem idling around 1000 rpms but in the water she stalls out. It also has a weird issue with throttling up. When I go to throttle her up, in the water, it is real rough up to about 1500 rpms and usually stalls out, like it was flooded, but if/when I get her past 1500 its all smooth sailing.

Scenario, I start it up with a couple bumps on the primer (choke), shift into gear, continue to bump the primer while giving it more gas to "get over the hump" and then she is fine by 2000 rpms. I am not sure if it is a starving or flooding issue as it is really hit or miss on what gets it running. Sometimes pumping the ball seems to help, sometimes not, sometimes too many hits on the choke and she dies out. It's a very delicate process leaving the pier!

First thing I was going to do is drop some sea foam through the tank to try and do an easy clean, followed by some engine tuner via the shrader valve. Then I am guessing a carb tear down / cleaning. Any other ideas suggestions?

Thanks.

-Svence

THEFERMANATOR · #2 07-22-2010, 09:03 AM

Take the airbox off and check the carb bodies for cracks first. The new style 150/175's seem to be having problems with the plastic carbs crackling from being old now. I guess OMC used a different grade of plastic on the EAGLE engines than they did the big ones. If they look good, then I would clean and soak them to clean out the air bleeds and pick-up jets. BUT YOU CAN'T USE REGULAR CARB DIP AS IT WILL EAT THE PLASTIC CARBS

. I use EVINRUDE engine tuner as my dip for the plastic carbs and have had great luck with it. Problem is it is EXPENSIVE! AND I don't know if it is still available by the gallon.

csvencer · #3 07-22-2010, 12:10 PM

Ferm-
I will take a look at the carbs this weekend and see what I find. Quick Q, what's the difference between the 150 carbs and the 175's? I just found another 98 (150 HP though) on CL for $500, thinking about grabbing it for the Lower Unit and Tilt Trim alone and parting out the rest. Any chance I could swap the carbs if needed?

-Svence

THEFERMANATOR · #4 07-22-2010, 12:28 PM

The 150 carbs should bolt right up, but it would make your engine a 150 instead of a 175. And you may need to change the jetting some as the 175 block has different porting than the 150 does.

csvencer · #5 07-24-2010, 06:26 PM

Ferm-
I just picked up a 2000 Johnson 150 with a blown head, looks like water got in the cylinders. I plan on swapping out the tilt trim, cowling, and some other odds and ends. The power packs should be the same, do I have to do anything after putting the new one on?

-Svence

csvencer · #6 07-24-2010, 06:27 PM

Ferm-
I just picked up a 2000 Johnson 150 with a blown head, looks like water got in the cylinders. I plan on swapping out the tilt trim, cowling, and some other odds and ends. The power packs should be the same, do I have to do anything after putting the new one on?

-Svence