Random stalling on take off 2000 Johnson 150

[kehi66]

Model number is: J150PLSSC. Took the boat out several days ago and the engine seems to be acting up after an extended period of off time while using trolling motor fishing. The engine runs great once idled up and at mid and top range but seems like the idle speed is too low to keep it running. Please give me any suggestions but I plan on doing the following. Thanks in advance

-Decarb engine
-change plugs after decarb
-Would like to check throttle roller timing arm but not sure how to get to this. As seen here http://www.bbcboards.net...otors
-Anyway to bump idle speed up?

[Mr Limpet]

Don't go screwing with the idle speed just yet. You motor started running different for a reason and it is not because the idle screw mysteriously backed out to a lesser idle speed.
You have a fuel delivery issue that is probably easily solved with a new OMC/BRP primer bulb. You have to get the one with the yellow male connector ports as it is the correct diameter fuel line for the demands of your motor.

Next thing to check is the timer roller adjustment. You have three screws on top of the engine @ the flywheel/starter area on top. Remove the black plastic to access the roller for the adj. It has one p-head screw, loosen it for the adjustment and move the roller as stated in the how to post.

There is also a throttle roller on the starboard side of the motor that is nothing more than a @ 1" piece of rubber hose over a metal post. This moves the throttle linkage when you move your shifter or hot foot. Sometimes this piece of rubber can wear out and fall away. Replace it with a piece of hose and that should get your motor back into spec for that.

You also need to inspect and PM the usual fuel related issues like fuel filter, stabil etc....

[kehi66]

Thanks for the info. I will check it tomorrow. I recently replaced fuel line and filter but the primer bulb that was on the engine is an aftermarket Attwood with black fittings. I think the primer bulb fittings might be 5/16" instead of 3/8"

[noodledude]

hey just a check and I am in no way a mech. but check your ground to the spark plug mine was doing the same thing and thats what it was apparently the ground would not make contact at that spped and it would cut off. just a thought Noodle