MX MPI Horizon 6.2 throttle body clean

scrumper

Active Member
SILVER Sponsor
Jul 10, 2020
152
Boat Info
1981 310 Vanguard Express
Engines
Twin Mercruiser 6.2 MPI Horizon FWC inboards
Risking a flaming for a dumb question here but do I need to remove the throttle body on this engine to clean it?

Having some slow idle & stalling problems and on inspection it’s pretty carbonized and the IAC muffler sponge is disgusting.

So I’m wondering if throttle body cleaner is safe if it drips into the intake manifold or whether I should just not risk the shortcut and take the extra time to pull the throttle body before cleaning it.
 
I just did the same thing. I didn't remove the throttle body but did a good cleaning with throttle body cleaner. The flame arrester was filthy and took some time to get clean. Be sure to change the IAC filter but don't spray the IAC. Mine worked out great afterwards I have a nice smooth idle again.
 
Risking a flaming for a dumb question here but do I need to remove the throttle body on this engine to clean it?

Having some slow idle & stalling problems and on inspection it’s pretty carbonized and the IAC muffler sponge is disgusting.

So I’m wondering if throttle body cleaner is safe if it drips into the intake manifold or whether I should just not risk the shortcut and take the extra time to pull the throttle body before cleaning it.
If you clean it still installed, just leave the throttle wide open without the flame arrester for 30 minutes. Most of it will evaporate and it should start relatively easy. You may have to use the “clear flood” procedure if it doesn’t start.
 
Thanks Espos4 and Brite Idea, that's encouraging and thanks for the advice. I get the cleaner can evaporate; what about the sludge that I'd be washing off?

EDIT: starting to really like this idea of doing it in situ, the little TB gasket is $77 each side!
 
That worked a treat, thanks guys. Shitty 450rpm idle is no more. (Now it’s too fast but that’s another post! I expect the IAC cooked itself trying to compensate for all the gunk.)
 

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