Rough/Won't idle Black Max 150

[REDRIGHT]

82-84 Black Max 150 sn 6132562<br />Runs great at higher rpm but coughs and splutters at idle.Has now developed into a will not run at idle.Have replaced thermostats all six coils sparkplugs.How do I check stator trigger and switch boxes?

 

[WillyBWright]

Re: Rough/Won't idle Black Max 150

Welcome to iboats. <br /><br />You're barking up the wrong tree. You have some clogged and/or sticky bleed valves. For the most part, they can be removed with a 5/16 wrench and cleaned with spray carb cleaner. Most will clean-up, but you may have to change a few. There is a screen that clogs and a check valve that sticks. I believe there are seven of them. One for each cylinder and one for the top/bottom crank bearings. Look on the intake manifold near the carbs.

 

[REDRIGHT]

Re: Rough/Won't idle Black Max 150

Thankyou for your advice WillyBWright I will check it out.

 

[andy6374]

Re: Rough/Won't idle Black Max 150

Try Willy's suggestion.<br /><br />If that doesn't work, check in the carb throats to make sure the throttle shutters are completely closed at idle.<br /><br />If not, might be time for a carb cleaning

 

[Texasmark]

Re: Rough/Won't idle Black Max 150

And when you are through, do a decarb with Sea Foam. Great stuff.<br /><br />I have a different engine but had same problem...almost, never actually quit at idle. Top end ran like a scalded cat. Started using Sea Foam. Different engine.<br /><br />Mark

 

[REDRIGHT]

Re: Rough/Won't idle Black Max 150

Looks like you were on the mark WillyBWrightI pulled out the bleed check valves (only 5 on my engine according to diagram)Three out of five malfunctioning, cleaned them with carb cleaner reinstalled runs beautifully.Still I am going to replace them all along with the old vacuum lines as they are showing signs of age.Will post result when new parts are installed. Thanks again