water treatment for valves???

[chuck hahn]

OK.. Never heard of this one before.. Old dude was checking out my 77 at bike night tonight and was digging it a lot and telling me about BACK IN THE DAY stories. Anyways he tells me to take off the airbox and get the engine up to operating temperature and rev up the engine and use a spray bottle to spray a mist into each carb a few times.. He says this will loosen carbon build up from the valves and lets them seat better to do the shim adjustments...what that all about? anybody ever heard of this treatment??

[Nessism]

Adding water creates steam, which can help loosen carbon but I don't see the point. Some carbon build up is normal and nothing to worry about.

[chuck hahn]

it sounded like snake oil to me so i threw it out there....i know i need to do the valves on both my zukes soon.. I am a bit timid about it though..I was looking at the search for some tolerances for the 750 8 valve but hadnt seen it yet.. i was thinking that from waht i have seen is too shoot for a .04mm overall tolerance..

[piester]

i have done this on a few cars. what it does basically is it loosens carbon buildup on the valves and seats. this helps the valve to seat better and helps with compression. once carbon starts to build up the valve wont seat properly. i word of warning thow. make sure the water is hottttt. cold water could cause warping or cracking of aluminum parts. also i would recomend using distilled water. tap water has minerals in it and yeah you dont wanna spray that in there. also, spray slowly. very slowly. count one one thousand two one thousand, and so on, every time you say a number spray the bottle. do 2 or 3 sprays and move to the next cylender. once you get to the end start at the beginning again. bike needs to be at 3/4 throttle or higher, not with choke, the actual throttle.

as a side note, most people think that water in the engine is a bad thing. this is not true. as long as it is in the propper amount water injection can actually improve drivability, gas milage, and increase hp and tq. the reason behind this is the water vaporizes and creates oxygen and preassure, this allows the fuel to burn cleaner, the preasure created will raise the effective compression ratio without causing detonation.
sorry i cant spell

[chuck hahn]

so if i boil a pan of water then a medium fine mist 2 or 3 times then move on and then go down the process again......just to be sure i am understanding your reply correctly.

[ranger rick]

hey all! this is actually a useful technique for cleaning not only the valves but the piston dome too. if you look in the racing catalogs you will find water injection kits for high performance and diesel engines as it lowers egt's, increases compression,prevents detonation. however I would recommend that if your doing this for the first time on an old engine DO IT OUTSIDE because you are going to get a lot of nasty smoke out the exhaust the first few times.and like piester said use hot water in your bike.being aircooled we don't have the thermal mass that a water cooled engine has to control heat fluctuaions that lead to parts cracking.

[ranger rick]

oh by the way it's not really the steam that removes the carbon. when the 212 degree steam hits the 500+degree carbon the sudden temp change shatters the carbon allowing it to be blown off by airflow and cumbustion turbulence.

[chuck hahn]

MAN..I sure am tempted to give this a try.. just over 35,00 on the 77 and i just over 37,000 on the 78...gonna go try and find some metric feeler guages tomorrow..

[ranger rick]

whoops < I meant combustion. gotta slow down when I type.

[Nessism]

There won't be any carbon between the valve and seat if the clearances are properly maintained. If the clearances are NOT maintained, the valves will burn. In either case, no worry with burning off carbon.

[piester]

damn i thought i put that in there about the temp change cracking it lol. give her a try. start small. do one spray and see how the bike runs. going too slow or too little wont hurt as much as going too fast or too big. the mist wont damage anything. actual liquid water will. water cannot compress. it will stop the piston dead no matter how fast its going. when i used to drift i was dyno tuning an sr20dett for my 240sx. ever heard an engine go from about 10 grand to 0 rpms in a 10th of a second? didnt break the crank, twisted it 500ish degrees.

[Macmatic]

ever heard an engine go from about 10 grand to 0 rpms in a 10th of a second? didnt break the crank, twisted it 500ish degrees.

That would be one to hang on the wall for sure.

/\/\ac

[ranger rick]

hey piester,yep I've heard that.the next thing I heard was my wallet deflating.roflol

[OldVet66]

Having gone through that one, I've also heard from the old timers a good puff of Babbo (like Comet) through the carbs helps seat new rings real quick.

[rustybronco]

MAN..I sure am tempted to give this a try..

Chuck, forget the water. adjust the valves and be done with it.

do you have or need the bucket depressing tool?