Quick Question On Intake Mani

[B3M2W5]

I am running into a problem with my intake mani. I have noticed that the inside of it is coated with some sort of dirt or debrie, im not sure what it is but its not comming off with just gas, i tried brake cleaner but that didnt help much, i can scrape it off but run into an issue with getting some thing up inside of the plenums.
My question is what is the best way to clean these, sense they are plastic i dont want to use something to harsh, i was thinking carb cleaner but thought maybe that would like start eating the plastic. I am also an auto tech student and have accses to parts cleaner but dont want to hurt it, their not cheap.
Any info or input would be really helpfull kind of on a time crunch its getting cold and i dont want to ride a Rocket in the snow.

[lateapex31]

Try using a hose and car wash brush with lots of dawn soap. The high pressure and flow of the hose should get most of the large debris, and a skinny wheel brush should get up into the plenum and runners. Maybe even one of those bottle brush type things. I think Jegs sells them for cleaning out oil galleries in blocks. The deposits are most likely hydrocarbons (ie. fuel and oil vapors) built up over time.

[Jordan]

Lacquer thinner dissolves said deposits very quickly. It won't bother the composite plastic.

[87-325ic]

a pressure washer works great on m20 manifolds.

[B3M2W5]

Ok thatnks guys, and sorry and im glad people knew what i was talking about as i failed to mention its an M50 mani, sorry about that.
But lacur thinner works hmm i might have to try that i went a head and used some carb cleaner and its seemed to work well
I just sprayed it in the the bottom of the ports as i held it up and then stoped and let it drain out, and repeated this till the liquid was no longer brown
I wornder if it was carbon i just didnt think it would be in there due to so much air and the fuel only really being at the bottom but it was coated about 3/4 of the way up the plenums from what i could see
I might pull the rail back off and the injectors and try the Thinner i never thought of that.
Thanks agian for you help guys