decarb procedure

gofastsandman · 07-03-2009, 03:36 PM

Thanks for being here. I have a 1996 EX150EXEDB Rude. I do not have the owners or factory tech manual. I have owned it for 2 years and want to decarb it. I have been confused because different brands of decarb say different things. No muffs, yes muffs. Soak overnight, soak 15 mins.. Run at 5000 , run at fast idle etc. I`ve been told the Merc powertune is the stuff to get.
I also had an old time mechanic tell me to empty the filter and bowl into the tank and fill with Powertune. Then run at 2000. Said this was the best method as the carbs get cleaned too. How would the motor get any/proper lubrication this way? I run premix. No VRO.
I found this service 2 weeks ago and have been pouring through the related threads. Thanks again.
GFS

A1 Outboard · 07-06-2009, 03:59 AM

Internal engine cleaner is not a good lubricant, it must be used with oil. You run the cleaner through the crankcase to clean the bottom piston rings. Your engine should be equipped with a valve on the primer which will allow you to attach a hose from Bombardier's Engine Tuner. The valve has a cap that looks like a valve stem cap for your car. It is attached to the small red manual primer valve on your outboard. The instructions on the can of Engine Tuner are the ones to follow. When you restart the engine DO NOT run above idle speed untill the smoking has stopped. The cleaner will clean out the oil in the engine as well as the carbon. When the smoking stops you are running on the correct fuel oil mixture. There is no harm in decarbing the engine on the flush muffs. Most dealers do it this way. The black junk that comes out the exhaust is the carbon. It should be biodegradeable, but may stain your drive way. The cleaner is not instant acting, this is why the instructions tell you to leave it in for at least three hours. If you leave it in too long the crank seals may be damaged.

gofastsandman · 07-06-2009, 01:04 PM

Roger the Schraeder valve. What are your thoughts on Dunk`s Seafoam method after the B.R.P. procedure. 900 hours and probably never done. Could I get an increase in WOT rpm?
Thanks again,
GFS

A1 Outboard · 07-09-2009, 05:04 AM

I dont know anything about seafoam. Decarb generally helps with starting and idle, it wont do any thing at wot unless the carboning is extreme.

bj · 07-09-2009, 10:19 AM

Just curious, is there any risks or harm by decarbing that could be done to an engine with 525 hrs and has never been decarbed? My engine is a Merc 2003 200HP EFI model. It runs and idles fine but wondering if I need to do this. Thanks.

A1 Outboard · 07-14-2009, 05:55 AM

Correctly done decarb will cause no problems. Reving up the engine before the chemical is out of the system or leaving the chemical in the engine too long can cause problems. The decarb can cause spark plug fouling, so you may have to install new plugs after the procedure.