since i don't want to type a novel i'll be blunt about this. does anyone have experience with the motorvac carbon tune system? if so could you briefly outline how i may perform this service without shelling out $800 for the service kit (i don't exactly run a full service station)? i'm willing to do some fabrication and buy their solvents, but what i really want to know is how the cleaning process is performed. how can this system possibly remove carbon from the top of the pistons and the back side of the exhaust valves without any major disassembly. i have a client that NEEDS this service performed (i recently removed a head to have the machine shop repair spark plug threads that were stripped, don't ask me how it happened -- they call only after stuff breaks). anyway i found at least 1/8" carbon buildup on the piston and even more in the combuston chamber. the head that was sent to the machinist is as clean as new, but the other one is still filthy inside and i could not justify removing the other head just to scrape the carbon off, so i did some research and found this motorvac thing. other than stating that there are three steps to performing this process the manufacturer is vague about how the service is performed and what the solvents are comprised of. any help is greatly appreciated.

Doesn't the motorvac system inject the cleaner through the FI sytem? BG and Wynns make similar systems for alot less. The old timey solution was to pour water through the intake when the engine is hot & revved. I don't know how safe that is or if I'd try it.

boschman, i don't really know how the motorvac thing works, honestly i was hoping that you would because i've seen you advise people to use those magic (and expensive) tools of the professional mechanic's trade such as ir thermometers and the like. i have used the water trick in the past and i do not know how effective it is at removing ALL of the carbon deposits, but usually a whole lot of stuff comes out of the tail pipe! anyway, the reason that i had intrest in the motorvac stuff is because the carbon deposits that i encountered in this engine were probably the thickest and hardest that i have ever seen. i'm not really surprised since the engine lives in a taxi cab and runs nearly 24-7, i just thought that something that would remove as much as possible would help to prolong this engine's life and hopefully be a step toward making it somewhat more fuel efficient (the intake valves had LOTS of buildup. a can of carb cleaner helped somewhat, but this stuff was so tenatious that i had to let is soak all night long). oh, well. in my opinion what all of these cabs need is to have the engines pulled and replace all of the wear items, gaskets, do the the macine work and all of that fun type stuff, but the owner is trying to make money not spend it. thanks anyway

As much as all the additive & cleaner companies would like to tell you about how their product will clean off those deposits, I haven't had much success. If it's a s bad as you say & it's bonded to the intake valve then removal & physical cleaning is the best way to get it done.

there is never an easier way. stupid chryslers are always plotting against me. at least my wabbit isn't.