"Using" Carb cleaning/carbon removing fuel additiv

[Dozer7380]

I've read plenty on what people like to use. I personally like Sea Foam but will be trying Techron soon. However none of these tell you how you should "use" them to most effectively remove build up. I know this may not matter but was wondering if anyone had a theory on this.

I can personally think of a couple theories.
1) Accellerate hard , quick wot bursts to redline: this causing a quick outflow of fuel from the carbs sweeping any junk out. Moves the valves faster to also remove built up carbon.

2) Ride under higher load : Drag the breaks in a higher gear , for short periods to build up heat that may help remove carbon , maybe open throttle to load the cylinders with cleaner?

3) Riding Fast , highway speed : Keep lots of fuel flowing through the carbs + more load, giving a constant flushing effect

*4)Bounce it off the revlimiter : LoL . hey you never know maybe the quick change in engine speed while revved up may help. Plus with no load the motor can rev quicker using more fuel, faster.

Possibly:
- Doing things at diffrent operating temps
- Spraying water/ manual water injection in the airbox while revving engine will give "steamcleaner" effect (water expands in chamber on ignition producing steam that will force out any crud)



Disclaimer: I am not a mechanic so dont go doing these things, they are just ideas to bounce around.

[The CyberPoet]

OK, the best way to remove carbon build-up is to use high detergent gasolines, which will remove it slowly over time. Having your jetting at the stoichiometric ratio will also help, as less carbon is left over after detonation to form build-up.

All fuel sold in the USA have some minimum amount of detergent (requirement), but the big name companies bundle up to ten times (10X) that minimum amount in their fuels (Shell and Chevron both immediately come to mind).

Techron additive says specifically how to use it: dump 1 bottle into the 12 -15 gallon gas tank of your car, then pump your gas to fill up. Since the Kat has a 5 gallon gas tank, 1/3rd of a bottle dumped in just before the fill-up will give your fuel the same consistency as the car version. Also means 1 bottle is good for three tankfuls.
Chevron's pump gas also has techron in it, although in a much weaker quanitity (about 1/50th the strength of what you end up with out of the bottle).

In terms of the effectiveness of the chemicals, most fuel system cleaners have a lot of light compounds that will try to evaporate out of the fuel in a couple days on a bike. The best way to use them is burn through a half tank on day one, leave it parked overnight (the fuel in the carbs is now filled with the techron) and then burn through the rest of the tank the next day. This maximizes the cleaning effect, at least on the fuel system, and to a lesser degree, on the engine.

If you have a lot of carbon in your engine, the best way to remove it is to literally break it up manually. Why? Because there is no other reliable way to get most of it out in a short period of time, plus you can control what happens to the carbon when it's removed. Using solutions like water-injection risks both warping the head and may release huge chunks of carbon that could scratch the crap out of your cylinder bores or even (in a worst-case scenario) physically interfere with the valves & piston's motion by jamming between them and cause the engine to seize.

As for the rest (none of which are effective in general):
(A) Accelerating hard doesn't make much of any difference on a typical motorcycle engine. Carbon is very hard and doesn't tend to break up.
(B) Riding under a higher load does not increase the odds of carbon breaking up -- if anything, it increases the odds of carbon build-up (carbon forms as a result of incomplete burning of the fuel normally).
(C) Ride fast falls under accelerating hard -- carbon is very hard and doesn't tend to break up.
(D) If you bounce your engine off the rev limiter, it shuts down the spark to the center two cylinders. And that just means more unburned carbon hanging around until it gets ignited in the exhaust pipe.

Good high-detergent fuels and healthy fuel-air ratios to do it the slow way; manual removal to do it the fast way.

Cheers,
=-= The CyberPoet

[Dozer7380]

Hmm "top tier" gass is harder to come by around here for some reason. Im in the refinery state. Recently Lukoil and Valeo have been taking over, chevron is non existent along with all other brands and Shell is rare. So if i run through 3 tanks of gas on a bottle of techron , Could I safely continue to use a splash every tank?

By manual, Im assuming removing the head and such.

[The CyberPoet]

Yes, you could safely use techron in every tank as long as you don't exceed the recommended strength regularly (running it weak is just fine).

By manually, yes, I mean removing the head and having at it... MD86 posted a nice thread with pics when he went at his.

Cheers,
=-= The CyberPoet

[md86]

Yeah , but my thread wasn't exactly a "how-too" . Just a "look what I'm bitching about NOW" .

http://www.katriders.com/forums/viewtopic.php?t=16671&highlight=inside+engine

[Teh_K]

Yes, you could safely use techron in every tank as long as you don't exceed the recommended strength regularly (running it weak is just fine).

But there are many posts where someone suggests that you do an immediate oil change after using Techron - as if it's bad for your oil (which could make sense since the two mix slightly). So... do you not have to do an oil change after running some Techron thru?

[The CyberPoet]

I said that it is my habit to run the techron as the last full tank of gas that I'll burn through before an oil change. It's just how I remember to do it at a reasonably cycle...

Actually, I initially said this because in theory, if your engine's valves were particularly grimy or nasty enough, it could loosen up sludge and build-up, and that -- combined with the lighter compounds being pushed into the oil around the rings -- would result in the mess being pushed into your oil. Add to that the minor possibility of a petcock leak combined with a bad float, and the stuff could flow into your crankcase (engine off), where it would really do a number on stripping down your oil's viscosity (more so than straight gasoline alone). Thus, if you are going to use it extra strong once every 3500 miles, as the last tank before your oil change is the ideal time to use it.

But using it on a healthy bike in a weak dose strength, I wouldn't be any more concerned about it causing issue than I would be of high-detergent fuels causing problems: as long as you don't have carb-float issues flooding your cylinders, it shouldn't be a problem.

ON SEMI-RELATED NOTE:
Malloc came to me this week and said his '99 Kat 750 was sucking through fuel like it was going out of style, giving him around 16-20 mpg (when it usually returned around 40 mpg driving the way he usually does).
Initially I suspected a bad float causing fuel leakage into the cylinder -- at least while he was actively driving (because the petcock wasn't in Prime). But on checking, the oil level hadn't gone up. We tore into the carbs' float bowls anyway -- and found nothing amiss. Pulling the spark plugs and checking the intake pathways for fuel, we found one cylinder with obviously liquid fuel on the intake side of the intake valve and an excessively clean spark plug...
Sealed up the float bowls, and turned the carbs back over, and tried to push the diaphrams upward with the side of the shaft of a long screwdriver (rather than pushing directly with a finger) -- and two of them didn't raise up freely, but stopped somewhere between 1/8th and 1/4 of the way into their travels. Culprit found!
We pulled out the diaphrams, diassembled them, washed both the rubber bellows and the hard plastic of the slides in warm water with dish detergent, then coated the rubber with a bit of the red rubber grease and coated the hard slide itself with silicone spray lube. Carbs' paths for the slides got cleaned out with carb cleaner and some qtips... reassembled, and off to test -- fuel mileage back up around 40 mpg.
It wasn't the problem I expected to find, but I do suspect that a fuel system cleaner would have probably kept some of the build-up off the exterior of the hard plastic of the slide mechanism itself (it appeared to almost be a moly compound on there -- a gray, thick compound).

Cheers,
=-= The CyberPoet