What is the best thing to do for a engine with carbon build

[cbxchris]

Without going into great detail I have a engine that has carbon build up on the valves. I`ve heard many things before but what does everyone use?? I had a friend say water!!! Said rev engine up and take a small spray bottle and spray water into the individual cylinders until it tries to bog...said a awful mess of carbon would come out. Honestly I`m scared to try that but he is a top mechanic with 30 years of bike experience. I`d prefer a additive or something to remove it. Thanks again for the replys!!! Chris

 

[saaz]

I have never heard of the water trick, but I think I have heard that some water injection may be beneficial. I have used redex (and there are probably similar things around) to soak in the cylinders to remove carbon (gee it smokes for a while after) but I don't know if this would do the valves. I remember (on a car) gradually squirting the Redex directly into the intake while running to loosen valve carbon buildup, a total of 150mls. This would do more for the valves and other carbon buildup.

 

[Anonymous]

Old guy trick.

Old guy trick.

Try this:

The old guy I used to work for showed me to use uncooked rice. Just put it in while its running. It pops like popcorn and works great.

Gavin

 

[Anonymous]

I think a half tank of 110 octane gas will probaby do it

 

[focus frenzy]

the water trick does work, I have used it numerous times at it will amaze you the amount of gunk that will blow out of the pipes.
it will be dificult to do because cv carbs dont like to work correctly with out the air cleaner.
you will need to warm the engine up good and toasty first before it will work good.
the water when it hits the cylinder will flash steam due to the high temperature in the cumbustion chamber blasting the carbon loose.

are you sure it is carbon? the detergents used in modern gas tends to turn to a tar like substance when it hits the hot intake valve.
valvoline puts out a additive that works pretty good for cleaning it out.

 

[Anonymous]

Oh No! the "BEST" thing is to tear the whole motor down have the head ported, polished, multi angle valve job with oversized valves, the biggest oversize pistons that will fit in the stock cyl sleeves(compression your choice)monster camshafts, smoothbore carbs...oh wait , I got carried away there for for a moment...the water actually works, if it's a really big load of build up you might think of pulling the mufflers off so when the 'junk' breaks loose it has an eaiser excape route, oh & do it outside not "aimed" at anything close(like a white garage door,don't ask me why I know that)
Also have you been running "Premium" gas? A low compression motor will carbon up quicker when you don't need the octaine because of the slower "burn rate" of high test. There isn't enough time to burn the slower burning high octaine so it leaves unburned fuel deposits(carbon) On max zuki there was a discussion of that topic since our Bandit's have low compression people were getting carbon build up because they were using too much octaine for the motor's needs.
Of course bigger pistons, more compression and port& polished head will be a fun ride and then you will need the high octaine :twisted:

 

[Don Lobacz]

I would recommend a simple head removal/cleanup. Wire brushing the valves is the only way to get them completely clean, and that will make them 1) lighter 2) smoother (less likely to cause detonation) and 3) better heat transfer conduits. A light lapping of the valves and you will be back to near-new combustion chamber sealing. I decarbon the piston tops with a several small wire wheels, first on a drill and then on a Dremel tool (make sure you wash/blow all of the soot out of the rings). Replacing the valves seals is another major advantage of a quick valve job. I also do a quick cleanup of the intake/exhaust ports.

 

[cbxchris]

I guess I should have explained this a little better. I ran a leakdown on a 1150 I have and all were 160 except #4. I would check it one time and it would be 60...then another 120. I ran a leakdown and it was in the head but on both sides...unusual. I had the valve cover off to check the valves which other than slightly loose were fine. I have seen this done before so I took a small socket and tapped lightly on the retainer...hey the compression came up 20 pounds...did this several more times and now its at 160 with all the others. I have ran the bike and rechecked...both leakdown and compression. It was a bit of carbon. This engine uses no oil...I basically was just asking the technique everyone used when in a situation like this. From being a old drag racer I didn`t have to worry about carbon...just melted pistons 8)

 

[wrench]

I have never heard of the water trick, but I think I have heard that some water injection may be beneficial. I have used redex (and there are probably similar things around) to soak in the cylinders to remove carbon (gee it smokes for a while after) but I don't know if this would do the valves. I remember (on a car) gradually squirting the Redex directly into the intake while running to loosen valve carbon buildup, a total of 150mls. This would do more for the valves and other carbon buildup.

That Redex really works, i dont think its availible in North America, i used it when living in the Uk. I added it to the gas on a old Triumph with a sticky exhaust valve. It took about a week of riding with Redex in the gas to clear up the problem, better than tearing the head off as far i'm concerned.
Leon send me some details on the water trick when you have time
Wrench.

 

[terry]

Do you guys get Pro-Ma fuel and oil additives there in the US? It's made in the US but may be marketed under a different brand name perhaps. I "overdosed" my wife's Nissan with it years ago, was only supposed to put 60 mils per 60 litre tankfull, her tank was only 1/4 full, but I thought I'd put it in before I drove to the gas station to fill up, anyway, this stuff worked so well it blew clouds of black smoke and soot out of the pipe for about 10 minutes, then it ran clean. We drove it to my parents place that afternoon (about 180 miles) and for the first time ever, it ran a clean pipe. Good stuff.
I've heard about the "water injection" trick working very well on cars, like one of the previous posts says, you have to warm the engine to normal temp, then spray (use a little spray bottle though, not your garden hose, ha ha) a little water into the carbs while holding the throttle at about 2500 rpm. (or else it will probably stall) The water mist turns into super-heated steam and "steam blasts" the carbon off.
Now I'm not advocating this, but I know that to "de-glaze" your cylinders to get your compression up a little, some people (I won't say who, they might be servicing your bike right now) use a teaspoon or so of abrasive powder cleanser like ajax or bon ami, holding it to the carbs, and as the vacuum draws it into the cylinder, once again, it showers everything around it with black soot, but apparently helps the rings bed back into the cylinders. I saw a friend do it on his old Honda CB750 and it worked ok, and his bike felt better to ride afterward, but I'm in two minds whether I'd risk it personally. :twisted:

 

[Anonymous]

I have never done it on a bike before, but I had done it to a car motor before and yes it does clean out the carbon. I was told to do it from an engine builder for drag cars.

 

[Anonymous]

Just pull the head and scrape the firing chambers with a wirebrush on a Dremel. I set mine at 30K rpm with the angled brush and the crud comes right off.

Then you aren't dumping all kinds of rice and water and additives into your engine and you will get the carbon completely off without damaging or reshaping (aka gouging) the firing chambers and pistons.

It only takes 3 hours to pull the head, scrape it and get it back together, and thats working slow on your day off with beer.

This also works great for removing old gasket material from the top and bottom head surfaces and the block surface.

 

[W1ngman6]

3 hrs with american beer

3 hrs with american beer

I'm from canada...it take 3 hrs with american beer ... how much longer with Canadian beer???

 

[terry]

Geez you Americans and Canadians are lucky with that "mild" beer you have over there, if we spend 3 hours drinking Aussie beer we're lucky if we can identify a bike, let alone work on one, ha ha!